Ch.13: Meiosis

Question 1

In asexual reproduction, one parent produces genetically identical offspring
A clone
This is done by _______
Cellular division

Answer 1

Mitosis

Question 2

two parents give rise to offspring that have unique combinations of genes inherited from the two parents

Answer 2

Sexual reproduction (Meiosis)

Question 3

What is the result of sexual reproduction

Answer 3

variation

Question 4

the scientific study of heredity and variation

Answer 4

genetics

Question 5

the transmission of traits from one generation to the next

Answer 5

heredity

Question 6

are the units of heredity, and are made of DNA

Answer 6

genes

Question 7

Each gene has a specific location called a______on a certain chromosome

Answer 7

locus

Question 8

Genes are passed from parent to offspring through reproductive cells called ______ (sperm and eggs)

Answer 8

gametes

Question 9

The two chromosomes in each pair are called

Answer 9

homologous pairs

Question 10

Human somatic (body) cells have how many pairs of chromosomes?

Answer 10

23 pairs of chromosomes

Question 11

Homologous pairs carry genes controlling the same inherited characters
Thus we all carry ??

Answer 11

two genes for each trait

Question 12

The 23rd chromosome pair are called the

Answer 12

sex chromosome

Question 13

human female and human male

Answer 13

XX & XY

Question 14

The 22 pairs of chromosomes that do not determine sex are called _________

Answer 14

autosomes

Question 15

Meiosis is preceded by the

Answer 15

replication of chromosomes

Question 16

Meiosis takes place in two sets of cell divisions: two cell divisions result in four haploid cells
Each daughter cell has only half as many chromosomes as the parent cell

Answer 16

meiosis I and meiosis II

Question 17

Meiosis is sometimes called ______ ________ because the chromosome condition is reduced from diploid (2n) to haploid (n).

Answer 17

nuclear reduction

Question 18

A gamete (sperm or egg) contains a single set of chromosomes, and is

Answer 18

haploid

Question 19

the haploid number is

Answer 19

23

Question 20

is the union of gametes (the sperm and the egg)

Answer 20

fertilization

Question 21

The fertilized egg is called a _________ and has one set of chromosomes from each parent
The _______ produces somatic cells by mitosis and develops into an adult

Answer 21

zygote

Question 22

conserves the number of chromosome sets, producing cells that are genetically identical to the parent cell

Answer 22

Mitosis

Question 23

reduces the number of chromosomes sets from two (diploid) to one (haploid), producing cells that differ genetically from each other and from the parent cell

Answer 23

Meiosis

Question 24

Three mechanisms contribute to genetic variation:

Answer 24

Independent assortment of chromosomes
Crossing over
Random fertilization

Question 25

Independent Assortment of Chromosomes deal with

Answer 25

Homologous pairs of chromosomes orient randomly during metaphase I
Each pair of chromosomes sorts maternal and paternal homologues into daughter cells independently of the other pairs
For humans (n = 23), there are more than        8 million (223) possible combinations of chromosomes

Question 26

Crossing over produces

Answer 26

recombinant chromosomes

Question 27

Crossing over occurs in __________, as homologous chromosomes pair up gene by gene
Crossing over contributes to genetic variation by combining DNA from two parents into a single chromosome

Answer 27

prophase I

Question 28

also adds to genetic variation;

any sperm can fuse with any egg

Answer 28

random fertilization