Chapter 9 Sex Repro & Meiosis

Question 0

Explain asexual reproduction.

Answer 0

DNA replicated, mitosis, identical offspring

Question 1

What is sexual reproduction?

Answer 1

Two parents, meiosis, different offspring

Question 2

Sexual reproduction produces ________ _________ among offspring. Which increases the chance that some offspring survive in ___________ __________.

Answer 2

Genetic diversity

Changing environments

Question 3

What is diploid cells?

Answer 3

2n

contain two full sets of chromosomes

Question 4

What does homologous pair mean?

Answer 4

A pair of chromosomes that are matching and look-alike and carry the same sequence of genes.

Question 5

What is a karyotype?

Answer 5

size ordered chart of all of the chromosomes in the cell. All in metaphase

Question 6

What are chromosomes 1 through 22 called?

Answer 6

Autosomes

Question 7

What is the 23rd chromosome?

Answer 7

Sex chromosomes

Question 8

What are alleles?

Answer 8

Alternative versions of the same gene

Question 9

Each chromosome is paired with an equally sized chromosome with the exception of the X and Y, true or false?

Answer 9

True

Question 10

What are gametes?

Answer 10

Sperm and egg cells

Question 11

What type of cells are gametes?

Answer 11

Haploid sex cells

Question 12

What does haploid mean?

Answer 12

N

Contain only one full set of genetic information instead of two

Question 13

What is formed when two haploid cells fuse at fertilization?

Answer 13

Zygote

Question 14

What type of cells is a zygote?

Answer 14

Diploid 2n

Question 15

What are germ cells? What type of division do they use?

Answer 15

Special diploid cells in the ovaries and testes, produces gamete cells. Divide by meiosis.

Question 16

What are somatic cells?

Answer 16

rest of the body’s diploid cells. Divide by mitosis.

Question 17

In meiosis how many times does DNA replicate and how many times does the nucleus divide?

Answer 17

DNA replicates once, nucleus divides twice creating 4 haploid non-identical daughter cells

Question 18

Gametes produced in meiosis are different because of three things:

Answer 18

Crossing over, independent assortment, random fertilization

Question 19

When does crossing over occur, and what does that mean?

Answer 19

Prophase one. Two homologous chromosomes exchange genetic material

Question 20

When does independent assortment occur and what does it do?

Answer 20

Metaphase one. Chromosome pairs align randomly.

Question 21

What does random fertilization mean?

Answer 21

It takes two to reproduce, different parents

Question 22

What is monozygotic?

Answer 22

When one embryo splits in two, resulting in separate identical babies

Question 23

What is dizygotic?

Answer 23

Two separate sperm cells fertilize two separate eggs. Fraternal twins. Offspring looks different

Question 24

Mitosis daughter cells contain ______ chromosomes.

Meiosis daughter cells contain ________ amount of chromosomes.

Answer 24

Same as parent

Half

Question 25

In meiosis, what allows for crossing over?

Answer 25

Homologous pairing

Question 26

Polyploidy means what?

Answer 26

Extra chromosome SETS

DEF-gamete with one or more complete sets of extra chromosomes

Question 27

What is nondisjunction?

Answer 27

Gametes having just one extra or missing chromosomes. Usually occurs when chromosomes fail to separate in meiotic division.

Question 28

What Is trisomy?

Answer 28

Child inherits 3 copies of Chromosome 21