Unit 6 - Mitosis & Meiosis

Question 1

Cell cycle

Answer 1

A cycle of growth, development, and division that most cells in an organism go through.

Question 2

Interphase

Answer 2

1st phase of the cell cycle (starts before mitosis) - divided into three stages

Question 3

Prophase

Answer 3

1st stage of mitosis - Chromatin condenses into chromosomes. Formation of spindle fibers, centrioles migrate to polls, and the nuclear envelope breaks down

Question 4

Metaphase

Answer 4

2nd stage of mitosis- chromosomes align themselves along the equator of the cell. Spindle fibers attach to the centromere of chromosomes

Question 5

Anaphase

Answer 5

3rd stage of mitosis - sister chromatids separate from one another. Spindle fibers shorten, pulling the sister chromatids to opposite poles of the cell.

Question 6

Telophase

Answer 6

Last and 4th stage of mitosis - A complete set of chromosomes now at each pole of the cell. Nuclear envelopes begin to reform, and spindle fibers fall apart.

Question 7

Cytokinesis

Answer 7

The division of the cytoplasm and other cell contents. Produces two identical “daughter cells.”

Question 8

Sister Chromatid

Answer 8

A cloned chromosome

Question 9

Centriole

Answer 9

Controls the cell during mitosis

Question 10

Centromere

Answer 10

Holds the chromosomes together

Question 11

G1

Answer 11

Interphase - Cells grow, carry out normal functions, and replicate organelles. Longest phase.

Question 12

S

Answer 12

Interphase - DNA is replicated in the nucleus of eukaryotic cells

Question 13

G2

Answer 13

Interphase - cell continues to do its normal job and growth continues

Question 14

M

Answer 14

Interphase - The division of the cell nucleus and its contents

Question 15

Somatic cells

Answer 15

Body cells ( blood cells, muscle cells, skin cells, etc.)

Question 16

Gamete cells

Answer 16

In animals: sperm and egg cells

• The DNA in gamete cells is passed onto the next generation

Question 17

Diploid

Answer 17

A cell that contains both chromosomes of a homologous pair

Question 18

Haploid

Answer 18

Having only one chromosome of each homologous pair

Question 19

Homologous chromosomes

Answer 19

2 chromosomes ( 1 from mother, 1 from father) that code for the same genes

• The genes on homologous chromosomes may code for different alleles - different versions of the genes they carry

Question 20

Autosomes

Answer 20

Chromosomes # 1–22. Contain genes for an organism’s physical features

Question 21

Sex chromosomes

Answer 21

Chromosome #23; Determines sex

Question 22

Meiosis l

Answer 22

Separates homologous chromosomes. Produces two daughter cells that are haploid (n) with replicated chromosomes.

Question 23

Prophase l

Answer 23

Chromosomes become visible, nuclear envelope breaks down, and crossing-over occurs, and chromosomes are forming a tetrad

Question 24

Metaphase l

Answer 24

Pairs of homologous chromosomes move to the equator of the cell

Question 25

Anaphase l

Answer 25

Homologous chromosomes move to the opposite poles of the separating cell

Question 26

Telophase l

Answer 26

Chromosomes gather at the poles of the cell followed by Cytokinesis forming 2 daughter cells

Question 27

Meiosis ll

Answer 27

Separates sister chromatids. Produces 4 daughter cells that are haploid (n) single (non-replicated) chromosomes

Question 28

Prophase ll

Answer 28

A new spindle fibers forms and moves to opposite poles of the cell, nuclear membrane dissolves, and non-additional DNA is replicated

Question 29

Metaphase ll

Answer 29

Chromosomes line up at the equator

Question 30

Anaphase ll

Answer 30

Centromeres divide and chromatids move to opposite poles of the cell separating chromosomes

Question 31

Telophase ll

Answer 31

Nuclear envelope forms around each set of chromosomes followed by cytokinesis forming 4 haploid daughter cells

Question 32

Crossing over

Answer 32

During prophase 1 —> when homologous pairs match up in prophase 1, they will exchange parts of DNA with their partner

Question 33

Law of independent assortment

Answer 33

Law of independent assortment —> when homologous pairs line up in metaphase 1, it is completely random which partner lines up on either side of the equator and may be different every time.

Question 34

Random fertilization

Answer 34

Random fertilization —> during fertilization, it is completely random which of the male’s sperm cells will fertilize the females egg cell