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Eukaryotic chromosomes are composed of a complex of 60% protein and 40% DNA. The name of this chemical compound is a

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Chromatin


some of the portions of the chromatin are permanently condensed so that their DNA is never expressed. all of these portions stains very intensly and are given a common name

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heterochromatin


In the human, the body cells (not sex-cells) contain two sets of chromosomes totaling

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46


which of the following sequence of cell-cycle phases is characteristic of eukaryotes?

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G1to S to G2 to M to C


the cell organelle replicates prior to genomic separation in ____phases

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G2


which one of the following represents interphase?

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G1+G2+S


plant cells typically achieve cytokinesis by
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forming a cell plate across the middle of the cell


in humans,the diploid # of chromosomes is 46. the haploid is 23. prior to mitosis in the cell cycle, the cell is the G2 phase. which statements is true?
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The homologous chromosomses have all been copied through DNA replication and are now sister chromatids.


if a cell has 32 Chromosomes prior to S and undergoes mitosis followed by cytokinesis, each daughter cell will have how many chromosomes?

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32


the point of connection between the two sister chromatids prior to being separted during anaphase is called

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centromere


the synaptonemal complex develops early in meiosis it is

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a lattice of proteins that hold homologues together


at the end of telophase II of meiosis,each of the four resulting cell contains

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one full set of chromsomes, each a single chromatid


the majority of meiosis I is spent in prophase I and metaphase I. after metaphase I is completed,anaphase I and telophase I quickly proceeds, thus ending meiosis. What immediately follows meiosis I?

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Prohase II


meiosis also has been called reduction division because

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there is a reduction in the chromosome number during two separate nuclear and cell divisions to produce gametes


which of the following statements regarding reduction dvision is false?

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reductiion division refers to both meiosis I and II


which of the following statments about cross over is false?

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crossing over takes place between non-sister chromatids


in 95% of cases of down syndrome, there is an extra chromosome 21 in every cell. this aneuploid  condiditon is the result of

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nondisjuction


early geneticists demonstrated al of the following about inherited traits except

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all traits breed true


when the etwo haploid gametes conain two different alles of a given gene. the resulting offspring is called

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heterozygous


the observable outward maniestion of the genes of an individual is referred to as its

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phenotype


what is the name of the cross that involves the mating of a hybrid F1plant with a homzygous recessive plant for the same trait?

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test cross


in peas, yellow-seeded plants might be homozygous or heterzygous we could find out which by crossinng these plants (assume that yellow is dominant to green for seed color)


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true breeding green-seeded planats


mendel's first law encompasses all of the following except

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all genes are found in an individual are not separable into gametes


let P=purple flowers and p=white, and T=tall and t=dwarf. of the 16 possible gamete combinations in the dihybrid cross, how many would be the phenotype white, tall?
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3


sometimes one gene pair will interact so as to control the expression of a second geen pair in an interaction called

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epistasis


when mendel crossed dark purple flowered pea plant with white flower pea plants, he never got any pea plants with light purple flowers. this was counter to the

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theory of blending inheritance


when mendels crossed 2 purple-flowered pea plants with each other, he obtained a phenotypic ratio of 3:1 (purple-flowered pea pants to white flowered pea plants) his results are consistent with which of the following sets of parents

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heterozygous pruple pea plants and heterozygous purple pea plant


Let Y=yellow and y=green and R=round r=wrinkled. you cross YYRR peas with yyrr. All of the F1individuals are yellow and round with a genotype of YyRr. you then perform a F2 cross and get the expected 9:3:3:1 phenotype ratio. which of the following is the correct genotypic ratio for yellow,round F2 individuals

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1/16YYRR,2/16YYRr,2/16YyRR, 4/16YyRr


Let R=red pigment and r=no pigment. in carnations, RR offspring make a lot of red pigment, rr offspring make no pigment and Rr offspring amke a small amount of red pigment, thus appearing pink. Pink carnations are therefore an example of

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incompelete dominance


Achondroplasia is a common form of dwarfism caused by autosomal dominants mutation. in the fibroblast grwoth factor reeptor gene 3. If a person with achondroplasia married and had children with a person  of normal height. what is the probability that both their first child and second child would have achondroplasia
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1/4


the theory of chromosomal inheritance was first proposed by

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Sutton


occasionally, the chromosomes fail to separate during meiosis. This phenonmenon is called

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nondisjunction


if a human female has two Barr bodies. it is almost certain that

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she deveolped froma fertilizied egg with a 3 X chromosomes


a human female with only one X chromosomes is said to have a condition called

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Turner syndrome


in sickle cell anemia, the defective hemoglobin differs from the normal hemoglobin by

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a simple amino acid substitution


Amnicentisis is a procedure that is normally used
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 for diagnosis of genetic disorder


in humans if a non-disjunction even led to an individual with a genotype of XXY, they would

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be maile b ecause they have a Y chromosome


if a female was a carrier for sex-linked color blindnedss, what percentage of her male children would also be color blind?

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50%


which of the following statements about calico cats is false?

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calico cats can be male or female


which offspring will inherit all their mitochondria DNA form their mother and non from their father?

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both son and daughters


the pairing of chromosomes along their length which is essetial for crossing over is referred to as

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synapsis


the zygote has

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two copies of each chromosomes


all of the following are animal cells are dipoids except

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gametic


crossing over of chromosomes takes place in
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prophase I


meiosis and mitosis difference

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mitosis is nuclear division, which ultimately leads to diploid somatic cells. meiosis is nuclear division, which ultimately leads to haploid gametes


the majority of meiosis I is spent in prophaseI and metaphase I after

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prophase II


A visual arrangement of all the chromosomes in a cell is called a
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Karyotype


What is the name for the position at which the chromosome is constricted so that the sister chromatids are manipulated as a unit?
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centromere


A cell described as 2N (diploid) with a chromosome content of 14 (14 chromosomes) is undergoing cell division. The convention is to say "the cell is 2N=14". An easy way to determine the number of chromosomes is to just count the number of centromeres. Which is the best description of a diploid cell at metaphase?

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2N=14


What does cyclin do?
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It accumulates so that the cell can access how much of it there is. This can stimulate cell division


haploid
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having only one set of chromosomes 2n


kinetochores
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replicated chromosomes are connect to each other by a disc shaped protein structure


all of the following are processes that promote new genetic combinations

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mitosis


name one advantage of sexual reproduction

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evolutionary progress


a diploid oranisim that has 2 identical alles for the same trait is called

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homozygous


mendel chose the garden pea for his work on inhertience for all of the following reasons except

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he failed his examination for a teaching certificate


mendel referred to the trait that was expressed in the hybrid F1 for first fillial generation as

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 dominant


in a typical mendel experiment on pea-seed color, if the dominate yellow seed bearing plant was crossed with the recessive green seed bearing plant the f2 generation will show what ratio

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3 yellow:1 green


yellow seeded plants might be homozygous or heterozygous. we could find out which by crossing these plants

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true breeding green-seeded plants


chaisma
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site where crossing over takes place


barr bodies

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site on a female cell where the X chromosome has been inactivated in females


non disjunction
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homologus of sister chromatids fail to separate


ratio describing the genotype which arise from a monohybrid cross of two heterozygous

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1:2:1


theory stating hereditary traits are carried on chromosomes
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chromosomal theory


female heterozygous for genes on the X chromosomes

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genetic mosaics


obtain information about the distance between genes and chromosomes

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genetic mapping


off spring resulting from crossover

 


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recombinant progeny


mapping genes in humans involves determining the recombination frequency between a gene ; does not cause a detectable phenotype

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anonymous marker


a site present at least 1 %, individuals differ by a single nucleotide. as genetic makers to map unknown gene/traits

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single nucleiotide polymorphisms


polymorphims
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difference between individuals in population


map unit

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1% of recombination frequency between 2 genetic loci


human genetic disorder
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- altered proteins encoded by mutate DNA -altered protein does not function, changing phenotype


during meiosis can create gametes having one too many or few chromosome

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nondisjunction


chorionic villli sampling

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sample of placenta tissue, detected early in pregnancy


chromosomes were first observed by

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walter flemming


scaffolds of proteins in aided by a complex of protein

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condensin


particular array of chromosomes of an organism

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karyotype


Which statement(s) is/are true about X-linked inheritance in Drosophila?
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A male inherits his X chromosome from his mothe


In humans presence of a Y chromosome determines maleness. In flies such as Drosophila sex is actually determined by the ratio of X chromosomes to the autosomes . If the diploid set of autosomes is represented as 2A then the ratio in females is XX/2A = 1, and in males it is 0.5. What would be the phenotypic sex of a human or a fly with one X chromosome and no other sex chromosomes, but with a normal set of autosomes? (Note: these individuals are not fertile)
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human female, fly male


Mitochondrial genes are inherited only from the female parent because
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mitochondria come from the egg, there are none in the sperm


Recombination of linked genes is caused by crossing over during prophase of meiosis I. Consider a double heterozygote of the genotype A b//a B. What are the parental and recombinant gametes if there is crossing over?
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Parental: AB, ab; Recombinant: Ab, aB


Nondisjunction can occur in meiosis I (Primary Nondisjunction) if the homologs do not separate, or in meiosis II (Secondary Nondisjunction) if the sister chromatids do not separate. What chromosome compositions could occur in the offspring from a couple where there was normal gamete formation in the female but nondisjunction of the Y chromosome in the male?
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XX, XYY, XO


barr bodies
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Xchromosomes inactived to prevent over expression of the alleles found on the X chromo in females


cellular process for recombination
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crossing over


OY
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letal combination


occurs when multiple gene are involved in controlling phenotype of a trait; influenced by one or more gene

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polygenic inheritance

ie: human ht


heterozygous
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an individual having two different alleles of same genes, and so giving rise to varying offspring. 


homozygous
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an individual having two identical alleles of a particular gene 


an individual heterozygous for Mendelian trait with simple dominance

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express dominiant phenotype


phenotype intermediate between homozygous dom and ress the trait is

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incompletely dominant


pleiotropy

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a single gene affecting more than one trait, refers to an allele having effect on the phenotype


heterozygote is intermediate in phenotype between the 2 homozygotes
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incomplete dominance


heterozygote shows some aspect of the phenotype of both homozygotes, ea allele has it's own affect

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comdominance ie; splotchy


extension of mendal

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environment causing pigment to change below 30 degree


type of gene interaction, in which gene can interfere with the expression of another

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epistasis


polymorphims
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difference between individuals in populations


Allele
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alternate form of a gene


euchromatin
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portion of chromatin not condensed where DNA is still being transcribed


heterochromatin
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portion of chromatin already condensed where dna is already transcribed


The spindle apparatus is fully formed by the end of


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prometaphase II


Separation of ________ occurs in anaphase II of meiosis.
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2 sister chromatids


At the end of meiosis II, there are
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four haploid cells, with each chromosome consisting of a single chromatid.


Replication of chromosomes occurs between meiosis I and meiosis II.


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false


The number of cells produced by meiosis is ________ the number of cells produced by mitosis.
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twice


The number of chromosomes in daughter cells produced by meiosis is ________ the number of chromosomes in daughter cells produced by mitosis.
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half


Chromosome duplication occurs prior to both mitosis and meiosis. t/f


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