Exam/Quiz Corrections

Question 1

Define crossing over and list the phase it occurs

Answer 1

Crossing over is when two homologous non-sister chromatids pair up with each other and exchange different segments of genetic material to form two recombinant chromosome sister chromatids. This occurs during prophase.

Question 2

Compare and contrast sexual reproduction with asexual reproduction.

Answer 2

Asexual reproduction involves one parent and produces offspring that are genetically identical to each other and to the parent. Sexual reproduction involves two parents and produces offspring that are genetically unique.

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

Which of the following is not true of meiosis

Answer 4

It contains only one cell division

Question 5

After what stage are homologous pairs completely separate

Answer 5

Telophase I of Meiosis I

Question 6

What does not occur during meiosis II

Answer 6

Addition of sister chromatids

Question 7

During the cell cycle, a cell grows

Answer 7

and divides

Question 8

What is not one of the phases of the cell cycle

Answer 8

mitosis

Question 9

The stage which the cell carries out cell cell functions is called

Answer 9

interphase

Question 10

The structure that attaches sister chromatids is called the

Answer 10

centromere

Question 11

Which is a difference between meiosis I and meiosis II

Answer 11

Meiosis II results in four haploid cells instead of two diploid cells

Question 12

What describes a gene

Answer 12

DNA segment

Question 13

Special proteins that bind to enzymes during the cell cycle are called

Answer 13

cyclins

Question 14

During this phase, chromosomes line up on the equator of the cell.

Answer 14

Metaphase II

Question 15

Chromosomes become visible, spindle fibers form, nucleus disappears.

Answer 15

Prophase II

Question 16

Suppose a new organism is discovered in Arkansas in 2019. The scientist determined that the haploid number is represented with by the total chromosomes shown below. Which of the following best represents the diploid number of the organism?

Haploid Breeding: Development of Pure Homozygous Line : Plantlet

Answer 16

6

Question 17

Homologous chromosomes line up on equator of the cell

Answer 17

Metaphase I

Question 18

Chromosomes are at the poles, two new nuclei are formed around chromosomes. After this phase two cells are formed.

Answer 18

Telophase I

Question 19

Homologous chromosomes pair up, crossing-over occurs.

Answer 19

Prophase I

Question 20

Sister chromatids separate

Answer 20

Anaphase II

Question 21

Homologous chromosomes separate

Answer 21

Anaphase I

Question 22

Sister chromatids are at the poles, 4 new nuclei form around them. After this phase 4 haploid daughter cells are formed.

Answer 22

Telophase II

Question 23

Type of cell division that results in 4 daughter cells that each have HALF the number of chromosomes as the parent cell.

Answer 23

Meiosis

Question 24

A cell containing two full sets of chromosomes (one from father and one from mother).

Answer 24

diploid

Question 25

A cell containing only one set of chromosomes (half the DNA).

Answer 25

haploid

Question 26

Initial cell created from the combination of a sperm and an egg.

Answer 26

zygote

Question 27

What is the end product of meiosis?

Answer 27

4 haploid gametes

Question 28

How many cells are produced from meiosis?

Answer 28

4

Question 29

When does crossing over occur?

Answer 29

Prophase I

Question 30

How many chromosomes are in a human gamete?

Answer 30

23

Question 31

How many chromosomes are in a human zygote?

Answer 31

46

Question 32

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 recessive?

Answer 32

25 percent

Question 33

The law of segregation:

Answer 33

two alleles for each trait separate during meiosis

Question 34

The law of independent assortment:

Answer 34

random distribution of alleles during meiosis

Question 35

Dr. Walther Fleming observed spermatozoa undergoing cell division in 1882. Observation, followed in 1902 by Sutton's meticulous measurement of chromosomes in grasshopper sperm cell development, provided definitive clues that the number of chromosomes was reduced in spermatozoan cell division, a process known as reductive division. Which of the following was Dr. Fleming most likely studying?

Answer 35

Meiotic cell division

Question 36

Suppose you were conducting an experiment using four different cell lines and after careful observation, you conclude that three out of the four cell lines reproduce resulting in haploid cells while one cell line yields cells with 2n chromosomes. What percentage of the cell lines you are investigating conduct mitosis?

Answer 36

25 percent

Question 37

The building blocks of DNA are called:

Answer 37

nucleotides

Question 38

Which of the following is NOT found in DNA?

Answer 38

uracil

Question 39

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

Answer 39

30 percent