Exam 2: Mitosis and Meiosis

Down syndrome,or trisomy 21,in humans is caused by an extra copy of the relatively small,acrocentric 21.Including only chromosome 21,the X chromosome (medium in size and somewhat metacentric),and the Y chromosome (small and acrocentric),draw one possible array of chromosomes in the four sperm cells produced by the complete meiosis of one primary spermatocyte.For the purposes of this question,assume that males with Down syndrome produce normal ratios of sperm cells.(More than one answer is possible.)

How many haploid sets of chromosomes are present in an individual cell that is tetraploid (4n)?

Normal diploid somatic (body)cells of the mosquito Culex pipiens contain six chromosomes.Assign the symbols A^mA^p,B^mB^p,and C^mC^p to the three homologous chromosomal pairs.The "m" superscript indicates that the homolog is maternally derived; the "p" indicates a paternally derived homolog.Assume that in the genus Culex,the sex chromosomes are morphologically identical.

If a typical G1 nucleus contains 2C (two complements)of DNA,a gamete that is haploid (n)contains 1C of DNA.

The centromere of a chromosome separates during anaphase.

How many haploid sets of chromosomes are present in a diploid individual cell with a chromosome number of 46? 32?

If a typical somatic cell has 64 chromosomes,how many chromosomes are expected in each gamete of that organism? A)8 B)16 C)32 D)64 E)128

Regarding the mitotic cell cycle,what is meant by a checkpoint?

For the purposes of this question,assume that a G1 somatic cell nucleus in a female Myrmecia pilosula contains 2 picograms of DNA.How much DNA would be expected in a metaphase I cell of a female? A)16 picograms B)32 picograms C)8 picograms D)4 picograms E)Not enough information is provided to answer the question.

There is about as much nuclear DNA in a primary spermatocyte as in ________ (how many)spermatids?

An interesting group of ants consists of several virtually identical,closely related species,with females having chromosome numbers of 18,20,32,48,60,62,and 64.If one crossed a female of species (A)with 32 chromosomes and a male species (B)with 9 chromosomes (males are haploid,and each gamete contains the n complement),how many chromosomes would one expect in the body (somatic)cells of the female offspring? A)4.5 B)9 C)25 D)32 E)41

List four terms used to describe the normal morphologies,with respect to arm ratio,of eukaryotic chromosomes.

The meiotic cell cycle involves two cell divisions but only one DNA replication.

List in order of occurrence the phases of mitosis.

A bivalent at pachytene contains four chromatids.

The house fly,Musca domestica,has a haploid chromosome number of 6.How many chromatids should be present in a diploid,somatic,metaphase cell?

The two terms reductional and equational generally refer to which stages of meiosis (I or II)?

During interphase of the cell cycle,________. A)DNA recombines B)sister chromatids move to opposite poles C)the nuclear membrane disappears D)RNA replicates E)DNA content essentially doubles

You may have heard through various media of an animal alleged to be the hybrid of a rabbit and a cat.Given that the cat (Felis domesticus)has a diploid chromosome number of 38 and a rabbit (Oryctolagus cuniculus)has a diploid chromosome number of 44,what would be the expected chromosome number in the somatic tissues of this alleged hybrid?

S phase is the part of interphase when DNA duplication takes place.