Exam/Quiz Corrections

Question 1

compare & contrast sexual vs asexual reproduction

Answer 1

Sexual: involves 2 parents and produces beneficial genes faster; offspring are genetically unique
Asexual: involves 1 parent and offspring are geneticallu identical to eachother and too the parent

Question 2

define crossing over & what phase it occurs in

Answer 2

2 homologous non-sister chromatids pair up with eachother and exchange different segments of genetic material to form two recombinant chromosome sister chromatids; occurs in prophase 1

Question 3

why must sex cells first undergo meiosis before fertilization?

Answer 3

To create haploid gametes that will be used in fertilization; need to reduce the number of chromosomes to n in order to correctly yield a 2n (diploid) organism during fertilization, if not problems may occur

Question 4

discuss two ways meiosis contributes to genetic variation

Answer 4

crossing over & random fertilization

Question 5

four examples of genetic variation

Answer 5

synapsis, random fertilization, crossing over, mutation

Question 6

Homologous chromosomes line up on equator of the cell

Answer 6

metaphase 1

Question 7

Chromosomes line up on equator of the cell

Answer 7

metaphase 2

Question 8

Chromosomes become visible, spindle fibers form, nucleus disappears.

Answer 8

prophase 2

Question 9

Suppose you are trying to predict the offspring of two plants, knowing that they are both heterozygous. What percentage of the offspring will be homozygous dominant?

Answer 9

25%

Question 10

The building blocks of DNA are called:

Answer 10

nuleotides

Question 11

Suppose you run a DNA analysis and determine that the genome consists of 20% thymine. How much guanine makes up the genome?

Answer 11

30%