Term
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Definition
| The union of haploid gametes to produce a diploid zygote. |
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Term
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Definition
| Component of the phenotypic variance that is due to genetic differences among individual members of a population. |
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Term
| Law of Independent Assortment |
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Definition
| Gregor Mendel's second law, stating that each allele pair segregates independently during gamete formation; applies when genes for two characteristics are located on different pairs of homologous chromosomes. |
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Term
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Definition
| A heritable, usually rare change in the DNA of a gene. Mutations are important in creating genetic diversity. |
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Term
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Definition
| Chromosomes created when crossing over combines the DNA from two parents into a single chromosome. |
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Term
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Definition
| An alternative form of a gene (one member of a pair) that is located at a specific position on a specific chromosome. For example, the gene for seed shape in pea plants exists in two forms, one form or allele for round seed shape (R) and the other for wrinkled seed shape (r). |
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Term
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Definition
| Breeding experiments between parent generation organisms that differ in two traits, for example, AABB x aabb. |
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Term
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Definition
| An allele that expresses its phenotypic effect even when heterozygous with a recessive allele; thus if A is dominant over a, then AA and Aa have the same phenotype. |
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Term
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Definition
| A cross between true breeding plants, homozygous for the trait of interest. Known as "First Filial Generation". |
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Term
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Definition
| A cross between members of the F1 generation. Known as "Second Filial Generation". |
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Term
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Definition
| The entire genetic identity of an individual (including alleles or gene forms) that do not show as outward characteristics, or the genetic composition at a specific gene locus or set of loci. |
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Term
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Definition
| (1822-1884) A Czech-Austrian monk who is often called the "father of genetics" for his study of the inheritance of traits in pea plants. Mendel showed that there was particulate inheritance of traits according to his laws of inheritance. However, Mendel's work was largely ignored until the turn of the 20th century, when its significance was understood for the first time. |
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Term
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Definition
| Having the same allele at the same locus on both members of a pair of homologous chromosomes. Homozygous also refers to a genotype consisting of two identical alleles of a gene for a particular trait. An individual may be homozygous dominant (AA) or homozygous recessive (aa). Individuals who are homozygous for a trait are referred to as homozygotes. |
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Term
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Definition
| In this context, a hybrid is a progeny individual from any cross involving parents of differing genotypes. |
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Term
| Law of Independent Assortment |
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Definition
| Gregor Mendel's second law, stating that each allele pair segregates independently during gamete formation; applies when genes for two characteristics are located on different pairs of homologous chromosomes. |
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Term
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Definition
| Gregor Mendel's first law, stating that allele pairs separate or segregate during gamete formation, and randomly unite at fertilization. |
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Term
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Definition
| Hybridization using a single trait with two alleles, for example, Aa x Aa. |
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Term
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Definition
| An ancestral line of descent, as diagrammed on a chart, to show ancestral history and to analyze Mendelian inheritance of certain traits including familial diseases. |
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Term
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Definition
| The formal study of the pattern of a trait in a pedigree to determine such properties as its mode of inheritance, age of onset, and variability in phenotype. |
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Term
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Definition
| The first generation of a cross. The letter "P" is the conventional designation for the "parental" generation. |
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Term
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Definition
| The observable structural or functional characteristics of an individual organism that result from the interaction of its genotype with environmental factors. |
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Term
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Definition
| A diagrammatic representation of a particular cross used to predict the progeny of the cross, developed by British geneticist Reginald Punnett. |
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Term
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Definition
| An allele which will only result in a specific phenotype when its counterpart allele is also recessive, or when no counterpart allele exists. |
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Term
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Definition
| The breeding an individual of unknown genotype to a homozygous recessive individual in order to reveal the unknown genotype. |
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Term
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Definition
| A type of allelic interaction in which the heterozygote simultaneously expresses traits of both homozygotes. |
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Term
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Definition
| Refers to the phenotype of a heterozygote that is intermediate between the phenotypes of the two homozygotes. |
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Term
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Definition
| An additive effect of two or more gene loci on a single phenotypic character, in other words, a phenotypic characteristic that is encoded by genes at many different loci. |
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Term
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Definition
| A dense object lying along the inside of the nuclear envelope in female, somatic mammalian cells, representing an inactivated X chromosome. |
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Term
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Definition
| The reciprocal exchange of genetic material between non-sister chromatids during synapsis of meiosis 1. |
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Term
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Definition
| Equalization in males and females of the amount of protein produced by X-linked genes. In placental mammals, this is accomplished by the random inactivation of one X chromosome in the cells of females. |
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Term
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Definition
| Genes that are located on the same chromosome. |
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Term
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Definition
| A genetic map based on the frequencies of recombination between markers during crossing over of homologous chromosomes. The greater the frequency of recombination between two genetic markers, the farther apart they are assumed to be from each other. |
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Term
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Definition
| One of four extraembryonic membranes that supports embryonic development; the first site of blood cells and circulatory system function. |
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Term
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Definition
| Describes the traits that are alternatives to the wild type. |
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Term
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Definition
| Region of an egg with a high concentration of yolk; this region is opposite the animal pole where cytoplasm is concentrated. |
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Term
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Definition
| One of the pair of chromosomes responsible for determining the sex of an individual. |
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Term
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Definition
| Region formed by flattening the embryonic vegetal pole at the beginning of gastrulation. |
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Term
| Vas Deferens (plural, Vas Deferentia) |
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Definition
| A coiled duct that conveys sperm from the epididymis to the ejaculatory duct and the urethra. |
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Term
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Definition
| Specification of gender (male or female). Sex determining mechanisms include chromosomal, genic, and environmental sex-determining systems. |
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Term
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Definition
| Part of the female reproductive system between the uterus and the outside opening; the birth canal in mammals; also accommodates the male’s penis and receives sperm during copulation. |
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Term
| Sex-linked Characteristic |
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Definition
| Characteristics determined by a gene or genes on sex chromosomes. |
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Term
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Definition
| A female organ where development of the young occurs |
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Term
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Definition
| The tube from the urinary bladder to the exterior in both sexes |
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Term
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Definition
| a diagnostic test, usually carried out between 15 - 20 weeks of pregnancy, in which a needle is inserted through the abdomen to remove a sample of amniotic fluid containing cells from the developing baby for testing. The procedure can be used to diagnose neural tube defects such as Spina Bifida or genetic defects such as Down's Syndrome. |
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Term
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Definition
| Outer ectodermal nutritive layer of blastodermic vesicle; in mammals it is part of the chorion and attaches to the uterine wall. |
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Term
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Definition
| One or a few chromosomes above or below the normal chromosome number. For example, three number 21 chromosomes or trisomy 21 (characteristic of Down syndrome) is a form of aneuploidy. |
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Term
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Definition
| The most abundant androgen hormone in the male body. A steroidal hormone secreted by Leydig cells located within the testes. It promotes the development of male secondary sex characteristics and the development of spermatozoa. |
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Term
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Definition
| A mode of inheritance in which a gene is passed on by either parent; in most cases, the child has a 50% chance of inheriting the gene; the expression of the gene (that is, the development of the physical trait or the disorder) can vary considerably among different individuals with the same gene. |
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Term
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Definition
| The male reproductive organs, in which sperm and reproductive hormones are produced |
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Term
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Definition
| A mode of inheritance in which an individual has two copies of a gene that requires both copies for expression, or development, of the trait. Both parents must be carriers (that is, they have only one copy of the gene and, therefore, do not have the physical trait that the gene confers) or have the trait (that is, have two copies of the same gene). |
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Term
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Definition
| Paired blocks of mesoderm just lateral to the notochord of a vertebrate embryo |
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Term
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Definition
| A serious genetic disease of excretory glands, affecting lungs and other organs; it causes production of very thick mucus that interferes with normal digestion and breathing. The carrier rate among all Caucasian individuals is approximately 1 in 25. If both partners carry the gene, there is a 25% chance that the child will have the disease. |
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Term
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Definition
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Term
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Definition
| Any of the elongated cells in the tubules of the testes to which the spermatids become attached; they provide support, protection and nutrition until the spermatids are transformed into mature spermatozoa. |
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Term
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Definition
| Also known as Trisomy 21, individuals with this condition have three copies of chromosome #21 instead of two. The condition is characterized by mild to severe mental retardation and other characteristic physical traits. Several tests are available during pregnancy to determine whether a baby will have Down’s syndrome. The most accurate tests, amniocentesis and CVS (chorionic villus sampling), count the baby’s chromosomes to determine the number of copies of #21. |
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Term
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Definition
| A gland in males that secretes a fluid component of semen that lubricates and nourishes sperm. |
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Term
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Definition
| Highly coiled tubes in the testes in which sperm are produced. |
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Term
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Definition
| Meiosis in which there is a failure of paired homologous chromosomes to separate, and therefore results in an abnormal number of chromosomes in the daughter cells. Nondisjunctions can result in diseases or abnormalities, and occasionally aid in adaptation and speciation. |
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Term
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Definition
| The fluid that is ejaculated by the male during orgasm; contains sperm and fructose and other secretions from several glands of the male reproductive tract |
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Term
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Definition
| The condition of having more than five fingers and/or toes, and is inherited as an autosomal dominant phenotype. |
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Term
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Definition
| The pouch that contains the testes in most mammals |
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Term
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Definition
| A condition in which a cell or organism has more than two complete sets of chromosomes. Humans have two sets, 2 x 23 (46) chromosomes, while wheat, for example, has 6 sets, 6 x 7 (42) chromosomes. |
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Term
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Definition
| A gland in human males that secretes an acid neutralizing component of semen |
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Term
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Definition
| Hormone secreted by the corpus luteum and the placenta; prepares the uterus for the fertilized egg and maintains the capacity of the uterus to hold the embryo and fetus. |
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Term
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Definition
| Sickle Cell disease is an autosomal recessive disorder that is marked by sickle-shaped red blood cells, occurring almost exclusively in people Africa and African descent, and characterized by episodic pain in the joints, fever, leg ulcers, and jaundice. |
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Term
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Definition
| A groove on the surface of an early avian embryo along the future long axis of the body. |
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Term
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Definition
| An inheritance pattern in which males are much more severely affected than females. An X-linked disease results from mutation of a gene that lies on the X chromosome. Females have two copies of the X chromosome (XX) while males only have one copy (XY). |
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Term
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Definition
| A structure in the pregnant uterus for nourishing a viviparous fetus with the mother’s blood supply; formed from the uterine lining and embryonic membranes. |
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Term
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Definition
| A hormone produced by the hypothalamus and released by the posterior pituitary. It induces contractions of the uterine muscles and causes the mammary glands to eject milk during nursing. |
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Term
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Definition
| Sequence of three nucleotides in tRNA that pars with the corresponding codon in mRNA in translation. |
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Term
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Definition
| The female gamete; the haploid, unfertilized egg, which is usually a relatively large, non-motile cell. |
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Term
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Definition
| Sequence of three nucleotides that codes for one amino acid in a protein. |
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Term
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Definition
| Also known as Fallopian Tubes |
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Term
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Definition
| Protein required for the termination of translation; binds to a ribosome when a stop codon is reached and stimulates the release of the polypeptide chain, the tRNA, and the mRNA from the ribosome. |
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Term
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Definition
| In animals, the structure that produces female gametes and reproductive hormones. |
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Term
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Definition
| The cyclic recurrence of the follicular phase, ovulation, and the Luteal phase in the mammalian ovary, regulated by hormones. |
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Term
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Definition
| The concept that several different codons code for the same amino acid; it is usually only the third base of the codon that changes. |
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Term
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Definition
| The development of organ rudiments from the three germ layers |
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Term
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Definition
| Enzyme that synthesizes RNA from a DNA template during transcription. |
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Term
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Definition
| Stage in formation of ovum, just preceding first meiotic division (primary oocyte), or just following first meiotic division (secondary oocyte). |
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Term
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Definition
| An elongated cellular cord, enclosed in a sheath, which forms the axial skeleton of chordate embryos, jawless fishes, and adult cephalochordates. |
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Term
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Definition
| Modification of RNA before it leaves the nucleus, a process unique to eukaryotes. |
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Term
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Definition
| Organogenesis of the nervous system in vertebrate embryos during which dorsal neuroectoderm cells of the neural plate (typically) roll up to form the neural tube which gives rise to the central nervous system. |
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Term
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Definition
| Programmed cell death, in which a cell degrades its own dNA, the nucleus ad cytoplasm shrink, and the cell undergoes phagocytosis by other cells without leakage of its contents. |
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Term
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Definition
| A tube of cells running along the dorsal axis of the body, just dorsal to the notochord. It will give rise to the central nervous system. |
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Term
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Definition
| In human embryology, formation of neural plate is the first step of neurulation. It is created by a flat thickening opposite to the primitive streak |
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Term
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Definition
| Mutation in which a single pair of bases in DNA is altered. |
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Term
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Definition
| Bilaterally symmetric infoldings of the neural plate that then seal dorsally to form the neural tube |
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Term
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Definition
| Mutation in germ-line cells; cells that give rise to gametes. |
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Term
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Definition
| A band of cells along the border where the neural tube pinches off from the ectoderm. These are ectodermally derived embryonic cells that differentiate into many skeletal, neural, and sensory structures unique to vertebrates. |
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Term
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Definition
| The process that corrects mismatched nucleotides in DNA after replication has taken place. Enzymes excise incorrectly paired nucleotides from the newly synthesized strand and use the original nucleotide strand as a template when replacing them. |
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Term
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Definition
| The third germ layer, formed in the gastrula between the ectoderm and endoderm; gives rise to connective tissues, muscle, urogenital and vascular systems, and the peritoneum. |
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Term
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Definition
| In the human female, that time of life when ovulation ceases; cessation of the menstrual cycle. |
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Term
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Definition
| A type of mutation where a codon is altered in the mRNA, resulting in a different amino acid in the protein. |
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Term
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Definition
| That portion of the ovarian cycle during which endocrine cells of the corpus luteum secrete female hormones. |
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Term
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Definition
| A heritable change in genetic information. |
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Term
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Definition
| Any environmental agent that significantly increases the rate of mutation above the spontaneous rate. |
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Term
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Definition
| A type of mutation where a codon specifying an amino acid is changed into a stop codon. |
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Term
| Nucleotide Excision Repair |
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Definition
| The process of removing and then correctly replacing a damaged segment of DNA using the undamaged strand as a guide. |
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Term
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Definition
| A change in a gene at a single nucleotide pair, see Base Substitution. |
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Term
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Definition
| Mutation where a codon is altered, but the codon still specifies the same amino acid. |
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Term
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Definition
| Mutation in a cell that does not give rise to a gamete. |
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Term
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Definition
| Lutenizing Hormone; A protein hormone secreted by the anterior pituitary that stimulates ovulation in females and androgen production in males. |
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Term
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Definition
| A pair of abnormally chemically bonded adjacent thymine bases in DNA, resulting from damage by ultra-violet radiation. The cellular processes that repair this lesion often make errors that create mutations. |
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Term
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Definition
| A rare hereditary skin disorder caused by a defect in the enzymes that repair DNA damaged by ultraviolet light. |
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Term
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Definition
| Located between the seminiferous tubules of the testes, these cells produce testosterone and other androgens. |
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Term
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Definition
| A cluster of cells in a mammalian blastocyst that protrudes into one end of the cavity and subsequently develops into the embryo proper and some of the extraembryonic membranes. |
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Term
| Differential Gene Expression |
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Definition
| Gene expression that responds to signals or triggers; a means of gene regulation; e.g., effects of certain hormones on protein biosynthesis. |
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Term
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Definition
| In the animal embryo, one of three basic layers (ectoderm, endoderm, mesoderm) from which the various organs and tissues arise in the multicellular animal. |
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Term
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Definition
| The process by which a genes coded information is converted into the structures present and operating in the cell. Expressed genes include those that are transcribed into mRNA and then translated into protein and those that are transcribed into RNA but not translated into protein. |
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Term
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Definition
| Process, by which an early embryo becomes a gastrula, acquiring first two and then three layers of cells. |
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Term
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Definition
| Follicle-Stimulating Hormone, a protein hormone secreted by the anterior pituitary that stimulates the production of eggs by the ovaries and sperm by the testes |
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Term
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Definition
| A type of RNA, synthesized from DNA, that attaches to ribosome sin the cytoplasm and specifies the primary structure of a protein. |
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Term
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Definition
| That portion of the ovarian cycle during which several follicles in the ovary begin to grow |
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Term
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Definition
| The synthesis of RNA from a DNA template. |
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Term
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Definition
| A microscopic structure in the ovary that contains the devolping ovum and secretes estrogens. |
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Term
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Definition
| Four membranes (yolk sac, amnion, chorion, allantois) that support the developing embryo in reptiles, birds, and mammals. |
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Term
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Definition
| The synthesis of a polypeptide using the genetic information encoded in an mRNA molecule. There is a change of language from nucleotides to amino acids. |
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Term
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Definition
| The primary female steroid sex hormones, which are produced in the ovary by the developing follicle during the first half of the cycle and in smaller quantities by the corpus luteum during the second half. Estrogens stimulate the development and maintenance of the female reproductive system and secondary sex characteristics |
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Term
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Definition
| Substance that stimulates transcription in an inducible system of genetic regulation; usually a small molecule that binds to a repressor protein and alters that repressor so that it can no loner bind to DNA and inhibit transcription. |
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Term
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Definition
| A coiled tubule located adjacent to the testes where sperm are stored |
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Term
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Definition
| DNA sequence in the operon of a prokaryotic cell. A regulator protein binds to the operator and affects the rate of transcription of structural genes. |
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Term
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Definition
| The innermost of the three primary germ layers in animal embryos; lines the archenteron and gives rise to the liver, pancreas, lungs, and the lining of the digestive tract |
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Term
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Definition
| The outermost of the three primary germ layers in animal embryos; gives rise to the outer covering and, in some phyla, the nervous system, inner ear, and lens of the eye |
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Term
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Definition
| Set of structural genes in a bacterial cell along with a common promoter and other sequences, that control the transcription of the structural genes. |
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Term
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Definition
| A secreting tissue in the ovary that forms form the collapsed follicle after ovulation and produces progesterone |
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Term
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Definition
| Process of nuclear and cell division in animal zygotes |
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Term
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Definition
| DNA sequence to which the transcription apparatus binds so as to initiate transcription; indicates the direction of transcription, which of the two DNA strands is to be read as the template, and the starting point of transcription. |
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Term
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Definition
| The outer of the double memrane that surrounds the embryo of reptiles, birds, and mammals; in mammals it contributes to the placenta |
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Term
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Definition
| The membrane or vascular envelope around some amniote embryos formed by fusion of mesoderm from the chorion and allantois |
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Term
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Definition
| Gene associated with an operon in bacterial cells that encodes a protein or RNA molecule that functions in controlling the transcription of one or more structural genes. |
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Term
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Definition
| Regulatory protein that binds to a DNA sequence and inhibits transcription |
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Term
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Definition
| Protein in eukaryotic cells that binds to consensus sequences in regulatory promoters or enhancers and affects transcription initiation by stimulating or inhibiting the assembly of the basal transcription apparatus. |
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Term
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Definition
| The structural and functional divergence of cells as they become specialized during a multicellular organism's development; dependent on the control of gene expression. |
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Term
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Definition
| Sequence that stimulates maximal transcription of distant gene; affects only genes on the same DNA molecule, contains short consensus sequences, is not fixed in relation to the transcription start site, can stimulate almost any promoter in its vicinity, and may be upstream or downstream of the gene. The function of an enhancer is independent of sequence orientation. |
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Term
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Definition
| Glands near the base of the penis in the human male that secrete fluid that lubricates and neutralizes acids in the urethra during sexual arousal. |
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Term
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Definition
| The more open, unraveled from of eukaryotic chromatin that is available for transcription. |
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Term
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Definition
| An early developmental stage of vertebrate embryos formed by cleavage of the fertilized egg, in which the embryo consists of a single layer of cells surrounding a cavity (the blastocoel) |
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Term
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Definition
| The fluid-filled cavity found in the interior of a blastula or blastocyst |
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Term
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Definition
| Coding region of a split gene(a gene that is interrupted by introns). After processing the exons remain in messenger RNA. |
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Term
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Definition
| It is the structure formed in early human embryogenesis, after the formation of the blastocoel, but before implantation. It possesses an inner cell mass, or embryoblast, and an outer cell mass, or trophoblast. The human blastocyst comprises 70-100 cells |
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Term
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Definition
| Nontranscribed eukaryotic chromatin that is so highly compacted that it is visible with a light microscope during interphase. |
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Term
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Definition
| The endoderm-lined cavity, formed during ht gastrulation process, that develops into the digestive tract of an animal |
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Term
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Definition
| The point on the surface of an egg that is diametrically opposite to the vegetal pole and usually marks the most active part of the protoplasm or the part containing least yolk |
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Term
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Definition
| A small protein with a high proportion of positively charged amino acids that bind to the negatively charged DNA and plays a key role in its chromatin structure. They act as spools around which DNA winds and they play a role in gene regulation. |
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Term
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Definition
| The inner most of the extraembryonic membranes forming a fluid-filled sac around the embryo in amniotes |
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Term
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Definition
| Intervening sequence in a split gene; removed from the RNA after transcription. |
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Term
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Definition
| One of the extraembryonic membranes of the amniotes that functions in respiration and excretion in birds and reptiles and plays an important role in the development of the placenta in most mammals |
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Term
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Definition
| Also known as miRNA, they are small RNA's typically 21 bp in length, that are produced by cleavage of double-stranded RNA arising from small hairpins within RNA that is mostly single stranded. The miRNAs combine with proteins to form a complex that binds to mRNA molecules and inhibits their translation. |
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Term
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Definition
| An egg cell that comes from fertilization. It contains the complete set of chromosomes received from the union of the male (sperm) and female (egg) sex cells. The zygote develops into the organisms adult body |
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Term
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Definition
| The strong membrane that forms around an ovum as it develops in the ovary. To fertilize the egg, a sperm must penetrate the thinning zona pellucida. |
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Term
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Definition
| The basic, beadlike unit of DNA packaging in eukaryotes, consisting of a segment of DNA wound around a protein core composed of two copies of each of four types of histone. |
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Term
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Definition
| Giving birth to living offspring that develop within the mother's body. Most mammals and some other animals are viviparous |
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Term
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Definition
| Binds to the poly(A) tail of eukaryotic mRNA and makes the mRNA more stable. |
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Term
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Definition
| A structure directly adjacent to the outer surface of the plasma membrane of an ovum. It is composed mostly of protein fibers, with protein receptors needed for sperm binding, binding to sperm plasma membrane receptors |
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Term
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Definition
| A spermatogonium (plural: spermatogonia) is an intermediary male gametogonium (a kind of germ cell) in the production of spermatozoa. They are cells located within the seminiferous tubules that produce sperm |
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Term
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Definition
| String of adenine nucleotides added to the 3' end of a eukaryotic mRNA after transcription. |
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Term
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Definition
| The haploid male gametid that results from division of secondary spermatocytes |
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Term
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Definition
| A preinitiation complex (abbreviated PIC) is an ordered combination of six general transcription factors.The preinitiation complex combines with RNA polymerase II near the transcriptional start site, to support a basal level of transcription. |
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Term
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Definition
| In biology, regeneration is an organism's ability to replace body parts. Starfish are able to regenerate lost arms. A new starfish may be regenerated from a single arm attached to a portion of the central disk. |
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Term
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Definition
| The immediate product of the transcription of one strand of the original DNA sequence. Many kinds of processing are now known which turn the immediate products of DNA transcriptions into Mature mRNA. |
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Term
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Definition
| An abnormal condition where an egg is fertilized by more than one sperm. It is common in In vitro fertilization methods |
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Term
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Definition
| The form of sexual reproduction in which the organism develops without fertilization by the male gamete. Parthenogenesis is common in some types of plants, invertebrates such as some types of aphids, bees, and wasps, as well as vertebrates such as some types of fish and lizards. |
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Term
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Definition
| Producing eggs that hatch within the female's body without obtaining nourishment from it. Used of certain fishes and reptiles and many invertebrates. |
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Term
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Definition
| Producing eggs that hatch outside the mother's body, embryos develop outside and each egg eventually hatches to a young animal |
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Term
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Definition
| Having both male and female reproductive systems in the same individual |
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Term
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Definition
A short sequence of DNA within the promoter of a gene that is able to bind a specific receptor complex and therefore regulate transcription. The sequence is most commonly a pair of inverted repeats separated by three nucleotides, which also indicates that the receptor binds as a dimer.
A gene may have many different response elements, allowing complex control to be exerted over the level and rate of transcription. |
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| Modification of RNA before it leaves the nucleus, a process unique to eukaryotes. |
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| A cis-acting RNA sequence in an exon or intron on which a complex assembles to repress the use of a splice site. |
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| The process whereby male and female gametes unite to form a zygote (fertilized egg) |
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| Large complex consisting of several RNAs and many proteins that splices protein-encoding pre-mRNA. |
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| When a sperm unites with the egg's plasma membrane, altering the zona pellucida which prevents other sperm from binding to and entering the egg. |
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| A promoter DNA sequence crucial in forming the transcription initiation complex in eukaryotes. |
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| The final enlargement of the digestive tract in birds, reptiles, amphibians, and many fish, through which solid wastes, urine, and the products of the reproductive system all pass prior to defecation, egg laying, or copulation. |
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| Proteins that bind to DNA sequences in eukaryotic cells and affect transcription. |
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| A simple water-soluble protein found in many animal tissues and liquids. Also known as "egg white". |
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| A form of cellular exocytosis that allows sperm to penetrate the zona pellucida of ovulated eggs |
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| A protein found in the endosperm of many seeds. It forms the outermost layer of the seed coat in some grains. During seed germination, hydrolysis in the seed causes the aleurone cells to break down into amino acids. |
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| A cap-like structure that surrounds the sperm head and contains enzymes that help in penetration of the egg. This structure arises from the Golgi complex in spermatids |
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| A division of the plant kingdom that includes all flowering plants; vascular plants in which double fertilization occurs resulting in development of fruit containing seeds. Divided into two major groups, monocotyledons and dicotyledons. |
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| The stalk of the pistil which connects the ovary to the stigma. |
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| The pollen-bearing organ at the apex of the stamen. |
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| The sticky part of a flower’s carpel, which traps pollen grains |
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| A group of plant growth hormones which stimulate cell division, enlargement, apical dominance, root initiation, and flowering. |
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| The pollen-producing male reproductive organ of a flower, consisting of an anther and filament |
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| The multicellular diploid form in plants undergoing alternation of generations that results from a union of gametes and that meiotically produces haploid spores that grow into the gametophyte generation |
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| A whorl of modified leaves in angiosperms that encloses and protects the flower bud before it opens |
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| An adaptation for terrestrial plants consisting of an embryo packaged along with a store of food within a resistant coat |
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| see pistil=(The female reproductive structure of a flower, consisting of stigma, style, and ovary. ) |
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| The outermost primary meristem, which gives rise to the epidermis of roots and shoots |
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| A primary meristem of roots and shoots that forms the vascular tissue |
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| Protective sheath covering the shoot apex of the embryo in monocotyledenous plants. |
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| Primary (Apical) Meristems |
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| Meristem is a type of embryonic tissue in plants consisting of unspecialized, youthful cells called meristematic cells and found in areas of the plant where growth occurs. The apical meristem is located just behind the root cap of root tips and at the tips of shoots |
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| The pollen tube acts as a conduit to transport sperm cells from the pollen grain, which has landed on the stigma, to the ovules at the base of the pistil. The pollen tube germinates from the pollen grain and grows the entire length through the stigma, style and ovules to reach the eggs. |
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| The part of the plant embryo from which leaves are formed. Monocotyledons have one cotyledon in each seed; dicotyledons have two. The cotyledons of many plants emerge above the ground after germination, and become photosynthetically active and are essential to early growth and establishment. |
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| The structures that contain the immature male gametophytes |
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| A characteristic of angiosperms in which a pollen tube carries two sperm cells to the female gametophyte in the ovule. |
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| The female reproductive structure of a flower, consisting of stigma, style, and ovary |
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| The tissue containing stored food in a seed that surrounds the embryo and is eventually digested by the embryo as it grows. |
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| A structure that develops in the plant ovary and contains the female gametophyte |
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| The portion of a carpel in which the egg-containing ovules develop |
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| The reproductive structure found on flowering plants (angiosperms) that contains male pollen-producing stamens and female egg-producing pistils. |
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| The smaller of the two kinds of spores produced in the sexual life cycle of a flowering plant, giving rise to the male gametophyte |
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| The ripened ovary (or ovaries) of a flower, and contains the seeds. Found in angiosperms. |
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| Plant tissue that remains embryonic as long as the plant lives, allowing for indeterminate growth |
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| The haploid, gamete-producing stage in the life cycle of a plant. |
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| The larger of the two kinds of spores produced in the sexual life cycle of a plant, giving rise to the female gametophyte |
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| Young leaves, recently formed by the shoot apical meristem, located at the tip of a shoot |
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| The process that occurs when a seed or spore begins to grow into a mature plant; germination requires moisture, oxygen and a suitable temperature. |
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| A general term for a cluster of flowers on one plant. An inflorescence can be very loosely arranged, tightly bunched, or anything in between |
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| A growth stimulating and dormancy breaking plant hormone. |
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| The equivalent of the stem in a young seedling. The vegetative organ between the root and the cotyledons, which is responsible for initial upward elongation growth |
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| The basic primary tissue of the growing tip of a stem or root, excluding the epidermis and vascular bundles, which gives rise to the cortex, rays, and pith. |
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| The placement of pollen onto the stigma of a carpel by wind or animal carriers, a prerequisite to fertilization |
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