Shared Flashcard Set

Details

CSET Genetics and Evolution
These are the vocabulary for the Genetics and Evolution Subset for General Science
26
Biology
8th Grade
06/23/2012

Additional Biology Flashcards

 


 

Cards

Term
trait
Definition
A qualitative characteristic; a discrete attribute as contrasted with metrical character. A trait is amenable to segregation rather than quantitative analysis; it is an attribute of phenotype, not of genotype.
Term
gene
Definition
The fundamental, physical, and functional unit of heredity. It is because a gene is a segment of DNA (on a specific site on a chromosome) that is responsible for the physical and inheritable characteristics of an organism.
Term
allele
Definition
One member of a pair (or any of the series) of genes occupying a specific spot on a chromosome (called locus) that controls the same trait. For example, a pair of alleles controlling the same trait, i.e. eye color: one allele codes for blue eyes, another allele for brown eyes.
Term
dominance
Definition
The property of a gene (or allele) when it suppresses the expression, or dominates the effects, of the recessive gene (or allele). Usually, a dominant allele is symbolized with a capital letter and the recessive allele a small letter, for example: Hh
Term
recessive
Definition
A gene (or allele) whose phenotypic expression is masked by a dominant gene (or allele). The recessive trait may be expressed when the recessive genes are in homozygous condition or when the dominant gene is not present. That happens when an organism inherits a pair of recessive genes from its parents.
Term
incomplete dominance
Definition
A kind of dominance occurring in heterozygotes in which the dominant allele is only partially expressed, and usually resulting in an offspring with an intermediate phenotype. Synonym: partial dominance.
Term
phenotype
Definition
The physical appearance or biochemical characteristic of an organism as a result of the interaction of its genotype and the environment, for example, skin color or height.
Term
genotype
Definition
A set of alleles that determines the expression of a particular characteristic or trait (phenotype).
genotype + environment + random variation → phenotype
Term
sex linkage
Definition
A condition in which a characteristic that apparently manifests more frequently in one sex than in the other is associated with the gene(s) located in the sex chromosome.
Term
monohybrid cross
Definition
A genetic cross between homozygous individuals but with different alleles for a single gene locus of interest. Monohybrid cross is one of the methods used by the geneticist, Gregor Mendel, in his garden peas experiments.
Term
dihybrid cross
Definition
A genetic cross between individuals with different alleles for two gene loci of interest. Was used to formulate his Law of Independent Assortment.
Term
Punnett Square
Definition
A tool that helps to show all possible allelic combinations of gametes in a cross of parents with known genotypes in order to predict the probability of their offspring possessing certain sets of alleles. Named after Reginald Punnett ,a British geneticist, who developed it.
Term
Law of dominance
Definition
In a pair of alleles, one trait may cover up the allele of the other trait; for example; brown eyes are dominant to blue eyes.
Term
Law of segregation
Definition
Only one of the two possible alleles from each parent passed on to the offspring from each parent, so that during meiosis, the haploid number ensures that hall the sex cells get one allele and half get the other.
Term
Law of independent assortment
Definition
Alleles sort independently of each other so that many combinations are possible depending on which sperm ends up with which egg.
Term
sexual reproduction
Definition
Reproduction that involves the fusion of gametes or haploid reproductive cells. Two gametes, one of each sex, fuse during fertilization to produce a zygote.
Term
asexual reproduction
Definition
Occurring without a fusion of gametes and by which offspring arise from a single parent, and inherit the genes of that parent only.
Term
mutation
Definition
(1) a change in the structure of a nucleotide sequence, often, but not necessarily, in a gene; (2) the altered sequence or gene resulting from such a change; (3) a change in the karyotype (chromosomal mutation) (4) an individual or type having such a change in its genetic makeup, and any descendants of that individual that in which it also occurs.
Term
DNA replication
Definition
The creation of a duplicate molecule from a template. During the replication of DNA the two strands of a duplex DNA molecule are first unzipped, then each of the separated ("parental") strands is used as a template for the synthesis of a new strand.
Term
deoxyribonucleic acid (DNA)
Definition
The molecule in living organisms that contains inherited information; it is made up of genes which in turn make up the chromosomes.
Term
evolution
Definition
The production of new forms of life over time, as documented in the fossil record.
Term
natural selection
Definition
A natural evolutionary process in which different heritable traits have a differential effect on the ability to produce offspring. Since there are variations due to sexual reproduction and mutations, some traits allow for better survival rates.
Term
causes of evolution
Definition
Certain factors increase chances of variability in populations which lead to evolution such as mutations, sexual reproduction, immigration, large populations and variation in geographic local.
Term
adaptation
Definition
1) a genetic process whereby a population or at type of organism is thought to have become better suited to its environment; (2) a trait considered to be the product of such a process.
Term
speciation
Definition
The evolutionary process by which new biological species arise which can no longer exchange genes with the original population.
Term
extinction
Definition
The end of an organism or of a group of organisms (taxon), normally a species. Species become extinct when they are no longer able to survive in changing conditions or against superior competition.
Supporting users have an ad free experience!