Question

11. Compare and contrast DNA and RNA.

12. During prophase I, the pairing of homologous chromosomes results in the formation of a ______.

	a.	cell plate
	b.	centrosome
	c.	zygote
	d.	chromatid
	e.	tetrad

13. During telophase ______.

	a.	tetrads form
	b.	the events of prophase are reversed
	c.	sister chromatids separate
	d.	chromosomes line up on the midline of the cell
	e.	the genetic material doubles

14. Which of the following occurs during prophase?

	a.	The mitotic spindle begins to form.
	b.	Chromosomes line up on the midline of the cell.
	c.	Nucleoli reappear.
	d.	Cytokinesis occurs.
	e.	Sister chromatids separate.

15. A cell that completed the cell cycle without undergoing cytokinesis would ______.

	a.	have two haploid nuclei
	b.	not have completed anaphase
	c.	be diploid
	d.	have two diploid nuclei
	e.	be haploid

1. 16. After completion of the cell, you would expect to have which of the following?

a.

four haploid cells, each with the same amount of genetic material but with different genetic information

b.

two diploid cells, each with the same amount of genetic material and the same genetic information

c.

four diploid cells, each with the same amount of genetic material and the same genetic information

d.

two diploid cells, each with the same amount of genetic material but with different genetic information

e.

a diploid zygote

17. All the offspring of a cross between a red-flowered plant and a white-flowered plant have pink flowers. This means that the allele for red flowers is ______ to the allele for white flowers.

	a.	pleiotropic
	b.	dominant
	c.	incompletely dominant
	d.	codominant
	e.	recessive

18. A homozygous plant that produces red flowers is crossed with a homozygous plant that produces white seeds. The seeds of all of the offspring are red. Why?

	a.	All offspring are heterozygous and the red allele is recessive to the white allele.
	b.	All offspring are heterozygous and the red allele is dominant to the white allele.
	c.	All offspring are homozygous and the alleles are codominant .
	d.	All offspring are homozygous and the red allele is dominant to the white allele. .
	e.	All offspring are heterozygous and the alleles are codominant.

20. What is the genotype of an individual who is heterozygous for trait A?

	a.	AA
	b.	AB
	c.	It would depend on what the trait is
	d.	Aa
	e.	aa

21. A child is shown to have a rare recessively inherited disease. The parents were tested for the gene, and both were found to be heterozygous. What is the probability of their second child having the disease?

	a.	1/2
	b.	1/32
	c.	1/16
	d.	1/4
	e.	1/8

Answer 1

Ans 11. Differences between DNA and RNA-

1) DNA consists of the bases A,G,C, and T, which RNA has Uracil instead of T.

2) DNA is more stable than RNA; the 2'-OH group makes RNA more labile, and hence reactive.

3) RNA mutates at a faster rate than DNA.

4) RNA is better for transmission of information, while DNA is better for storage of information.

Ans 12. e. Tetrad

This is the appearance due to the presence for 2 pairs of sister chromatids.

Ans 13. b. The events of prophase are reversed.

Nuclear envelope reappears at opposite end clusters of chromosomes; nucleolus, Golgi apparatus, ER reappear.

Ans 14. a. The mitotic spindle begins to form.

This is done in preparation for the chromosomes which will align in the middle plane, and migrate to opposite poles in the subsequent phases.