Bio exam ch11

Explain how the orientation of homologous chromosomes during metaphase I of meiosis contributes to greater variation in gametes. A. The random alignment of homologous chromosomes at the metaphase plate ensures the random destination of the chromosomes in the daughter cells. B. Because homologous chromosomes dissociate from the spindle fibers during metaphase I, they move randomly to the daughter cells. C. The homologous chromosomes are paired tightly during metaphase I and undergo crossover as the synaptonemal complex forms a lattice around them. D. Recombination of maternal and paternal chromosomes occurs in metaphase I because the homologous chromosomes are not connected at their centromeres.

A

Identify which of the following event(s) will occur during Prophase I of meiosis but does NOT occur during prophase of mitosis. A. Bivalents will form B. Chromatin will condense into chromosomes C. Centrioles will form in animal cells D. Nuclear envelope will dissolve

A

If the diploid number of chromosomes in mouse somatic cells is 40, how many chromosomes are present during prophase I? A. 40, each containing a pair of sister chromatids B. 20, each comprised of a single sister chromatid C. 80, each comprised of a single sister chromatid D. 80, each comprised of a pair of homologous chromosomes

A

In Meiosis I, _____ move into separate cells and in Meiosis II, _______ move into separate cells. A. Homologous chromosomes; sister chromatids B. Sister chromatids; paternal chromosomes C. Maternal chromosomes; paternal chromosomes D. Sister chromatids; homologous chromosome

A

In which stage of meiosis is the cell in? A. Metaphase I B. Anaphase II C. Metaphase II D. Anaphase I

A

The daughter cells produced by meiosis are _____. A. Genetically different from the parent and each other B. Identical to each other but genetically different from the parent C. Identical to the parent but genetically different from each other D. Genetically identical to the parent and each other

A

Which statement describes a similarity between meiosis and mitosis? A. Both create genetically different daughter cells B. DNA is replicated only once in both processes C. Both produce 4 daughter cells D. Crossing-over occurs in both E. Both halve the chromosome number of the parent cell

B

______ are sites of crossing-over visible under the microscope. A. Centromere B. Chiasmata C. Sister chromatids D. Tetrad

B

What is the difference between sister chromatids before and after anaphase II? A. Before anaphase II, the sister chromatids are separate; after anaphase II, the sister chromatids join and form a chromosome. B. There is no difference; they are still together as a single chromosome. C. Before anaphase II, the sister chromatids form a single chromosome; after anaphase II, each sister chromatid is an individual chromosome. D. Before anaphase II, the sister chromatids form a single chromosome; after anaphase II, the sister chromatids become homologous chromosomes.

C

Which does NOT occur in meiosis? A. Two nuclear divisions B. Four daughter cells at completion C. Two daughter cells at completion D. Formation of bivalents

C

One of the ways that sexual reproduction enhances the diversity of offspring from the same parents is through a process called crossing over. What are the entities involved? A. Sister chromatids B. Tetrads C. Nonhomologous chromosomes D. Non-sister chromatids of homologous chromosomes

D

When two pairs of homologous chromosomes join for crossing-over, the complex is called a _____. A. Sister chromatids B. Chiasmata C. Centromere D. Tetrad

D

Genetic variability in meiosis results from ______. A. Random joining of male and female gametes only B. Recombination between sister chromatids and homologous chromosomes C. Independent assortment of chromosomes only D. Recombination of homologous chromosomes only E. Recombination of homologous chromosomes, independent assortment of chromosomes, and random joining of male and female gametes

E

The manner in which chromosomes align themselves along the metaphase plate is completely random. This quality makes _____ possible. A. Metaphase I B. Fertilization C. Meiosis D. Synapsis E. Independent assortment

E

The chromosome number is halved by __________ and restored by ___________.

meiosis, fertilization