Term
| all cells in an organism other than their germ line cells or gametes are known as _________ cells |
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Definition
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Term
| mutations is somatic cells _______ transmitted to future generations |
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Definition
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Term
| ________ autosomal mutations are unlikely to result in a detectible phenotype changes |
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Definition
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Term
| dominant or (in males) X-linked mutations are _______ to be immediately expressed |
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Definition
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Term
| why are X-linked (in males) and dominant autosomal mutations extra noticeable during early development? |
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Definition
| early in development is when a small number of cells give rise to many other cells to create organs or tissues |
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Term
| if a dominant mutation takes place in an adult autosomal cell, the individual is ______ to express the mutant phenotype |
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Definition
| unlikely; mutations that occur in developed adult cells are often masked by thousands of other cells that have the wildtype phenotype |
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Term
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Definition
| an embryonic cell lineage that will form the reproductive cells |
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Term
| mutations that occur in a ______ cell may be transmitted to offspring |
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Definition
| germline (which turns into a gamete) |
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Term
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Definition
| only have one type of sex chromosome (i.e. females are XX) |
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Term
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Definition
| have two different sex chromosomes (ie. males have XY) |
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Term
| X-linked recessive genes are less likely to be expressed in ________ (hemigametic/homogametic) individuals and more likely to be expressed in ________ (hemigametic/homogametic) individuals |
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Definition
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Term
| when it comes to inheritance of genetic material, what is the difference between asexual and sexual reproduction |
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Definition
Asexual: genetic material is copied and results in offspring that are identical to the parent
Sexual: 50% of genetic material from male gamete and 50% from female gamete |
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Term
| True or false; dominance and recesiveness exist in haploid individuals |
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Definition
| false, haploid individuals have one copy of each chromosome and since dominance is relative there is no other trait to compare it to |
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Term
| gametes in a diploid individual will be ______ (ploidy) cells |
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Definition
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Term
| name the 4 phases of cellular reproduction |
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Definition
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Term
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Definition
| 1st growth phase (aka “Gap Phase”) where cell grows and starts to function like normal cell |
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Term
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Definition
| synthesis phase where chromosomes duplicate (in meiosis homologs have duplicatd) |
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Term
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Definition
| 2nd growth phase where cell prepares for mitosis |
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Term
| what are the 5 stages of mitosis |
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Definition
| prophase, prometaphase, metaphase, anaphase and telophase |
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Term
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Definition
| pairing of homologous chromosomes during prophase I of meiosis |
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Term
| tetrads consist of ____ (number) chromosomes |
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Definition
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Term
| what occurs during synapses to give rise to so much genetic variability |
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Definition
| recombination/crossing over occurs where chromatids on homologs switch pieces of DNA creating a unique chromosomal strand |
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Term
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Definition
| a chromosomal structure created in between synapsis and the formation of a tetrad |
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Term
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Definition
| homologs that form the tetrad |
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Term
| meiosis __ is considered reductional division because the number of centromeres are halved |
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Definition
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Term
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Definition
| the two sister chromatids that make up a dyad |
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Term
| True or false; in meiosis II, the number of chromosomes are halved |
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Definition
| false, the number of chromosomes stay the same because the number of centromeres stays the same |
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Term
| what is the difference between independent assortment and segregation |
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Definition
segregation ensures the seperation of homologs during creation of gametes in meiosis (i.e. red hair gene or black hair gene in one gamete, never both)
independent assortment claims that the assorting of chromosomes has nothing to do with one another (i.e. whether you get the green eyed gene or blue eyes gene when the gamete contains the brown hair gene is random) |
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Term
| given a probability question, if you see the word "and" you must ______ the probabilities |
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Definition
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Term
| given a probability question, if you see the word "or" you must _____ the probabilities |
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Definition
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Term
| given two homozygotes (Aa) what is the genotypic ratio |
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Definition
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Term
| iven two homozygotes (Aa) what is the phenotypic ratio |
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Definition
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Term
| what is the phenotypic ratio of a dihybrid cross (AaBb)? |
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Definition
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Term
| define: pseudoautosomal region |
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Definition
| : a region on both ends of the human Y chromosome that is also represented on the X chromosome (can synapse and recombine during meiosis). Genes found in this region of the Y chromosome are indistingushable from genes on autosomes |
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Term
| presence of the _________ region on a Y chromosome is critical to the segregation of X and Y chromosomes during male gametogenisis |
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Definition
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Term
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Definition
| orgnaism gains or loses one or more chomosomes but not a complete set (i.e. trisomy 21 means an extra chromosome 21) |
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Term
| aneuploidies originate from....? |
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Definition
| random errors durig meiosis such as non-disjunction |
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Term
| true or false; Fertilizing a gamete affected with a nondisjunction with a normal haploid gamete can result in a zygote with either 3 (trisomy) members or 1 (monosomy) member of the nondisjoint chromosome |
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Definition
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Term
| why can an abnormality in chromosome number be fatal? |
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Definition
| genes chromosomes code for proteins, and overdose or underdose of protein can be lethal depending on the chromosome and by how much its over/underdosing |
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Term
| monosomies are ____ lethal in plant |
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Definition
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Term
| which produces more viable offspring? Monosomy or Trisomy? |
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Definition
| Trisomy; - Addition of an extra chomosome produces more viable indivduals than the loss of one (both animals and in plants) if the chromosome involved is reletively small, but you will see phenotypic changes |
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Term
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Definition
| organism has complete extra haploid set(s) |
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Term
| If more than 2 haploid sets are present, its considerd ______ |
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Definition
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Term
______ (even/odd) numbers of chromosome sets are rarely properly maintained through __________ since polyploid organisms with ______ numbers of homologs often wont produce genetically _______ gametes
A) Even, Mitosis, uneven, balanced
B) Uneven, Generations, even, unbalanced
C) Odd, generations, uneven, balanced
D) unbalanced, meiosis, even, unbalanced |
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Definition
| odd, generations, uneven, balanced |
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Term
| what are the two ways polyploidy can arise? |
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Definition
| allopolyploidy, autopolyploidy |
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Term
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Definition
| a polyploidy caused by combining of chromosome sets from differing species due to hybridization |
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Term
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Definition
| addition of 1 or more sets of chromosomes, identical to normal haploid compliment of same species |
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Term
| why are aneuploidies of the X chromosome tolerated so well in humans? |
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Definition
| Barr bodies allow only 1 X chromosome to be active allowing for proper gene dosage regardless of how many X chromosome the individual has |
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Term
| why are aneuploidies of the Y chromosome tolerated so well in humans? |
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Definition
| Y chromosomes are relitively small and have very few genes (most of which are related to male sexual development) therefore, having an extra copy does not have a large effect |
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Term
| true or false; It is viable to be missing a Y chromosome (i.e. XO) but lethal to be are missing an X chromosome (i.e. YO) |
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Definition
| True;Missing an X chromosome can be lethal (YO) because X contains too many genes to be missing |
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Term
| can fertility be hindered by inversion of a chromosome? |
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Definition
| Yes; inversion hinders normal linear synnapsis during meiosis causing chromosomes to be broken in half during anaphase, giving rise to gene insufficiency |
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Term
| Aneuploidies, Euploidies and chromosomal inversions all effect _______, most of the time leading to _______ |
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Definition
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Term
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Definition
| SRY is the sex determining region on the Y chromosome (controls male sexual development) |
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Term
| what is TDF and what does it do? |
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Definition
| TDF is a protein encoded by the SRY that causes undifferentiated gonadal tissue of embryo to form testes (aka testes determining factor) |
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Term
| in birds __ (ZZ/ZW) is considered female and __ (ZZ/ZW) is considered male |
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Definition
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Term
| in drosphila (fruit flies) how is sex determined? |
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Definition
| : ratio of X chromosomes to number of haploid sets of autosomes present (females equal 1:1 ratio while males are a a 1:2 ratio) |
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Term
| how is sex determined in lizzards? |
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Definition
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Term
| in C elegans, females are __ (XX/XO) while males are (XX/XO) |
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Definition
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Term
| how is sex gene dosage compensated in dropsophila |
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Definition
| Male X-linked genes are transcribed at twice the level of the comparable genes in females |
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Term
| how is sex gene dosage compensated in birds |
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Definition
| local compensation is done on a gene by gene process in each tissue and/or developmental time point |
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Term
| how is sex gene dosage compensated in C Elegans |
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Definition
| X hypoactivation (limit gene expression by 1/2) in XX individuals |
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Term
| how is sex gene dosage compensated in Mammals |
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Definition
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Term
| the Xic loci in an X chromosome is used for _____ prior to inactivation |
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Definition
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Term
| Xic (aka _________) is located on the _ arm of the X chromosome and is considered the ______ _______ _____ |
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Definition
| X-inactivation centre, P, major control unit |
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Term
| Expression of Xic is only found on the ________ X chromosome |
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Definition
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Term
| Xic works by having its RNA product _____ the X chromosome that produced it, turining it __________ (hetero/euchromative) |
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Definition
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Term
| True or false; initially, all X present X-chromosomes transcribe Xic at a low rate |
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Definition
| true; but as inactivation kicks in the X chromosome designated to be inactivated’s transcription is enhanced |
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Term
| True or false; maternal phenotype from genes found in the cytoplasm (i.e. mitochondrial or chloroplast DNA) and not paternal will always be expressed in offspring |
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Definition
| True: Cytoplasmic DNA mainly inherited from mother (sperm much smaller so can’t hold much) |
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Term
| True or false; although cytoplasmic contents may vary, daughter cells will still be identical due to perfectly split nuclear DNA |
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Definition
| False; The cytoplasm also contains DNA (i.e. mitochondrial/chloroplast) therefore if cytoplasmic contents vary, it will result in differing phenotypes among daughter cells |
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