Cell Reproduction

Question 1

True or false: somatic and reproductive cells reproduce differently

Answer 1

true

Question 2

What is generated during somatic cell division?

Answer 2

two genetically identical cells

Question 3

How many chromosomes does a somatic cell have?

Answer 3

46

Question 4

What is the division of the nucleus in somatic cell division called?

Answer 4

mitosis

Question 5

What is generated during reproductive cell division?

Answer 5

produces gametes (sperm and egg), 4 non genetically identical cells

Question 6

How many chromosomes do gametes have?

Answer 6

23

Question 7

What is the division of the nucleus in reproductive cell division called?

Answer 7

meiosis

Question 8

What is the division of the cytoplasm called?

Answer 8

cytokinesis

Question 9

What are somatic cells that contain 23 pairs of chromosomes called?

Answer 9

diploid (2n) cells

Question 10

What are homologous chromosomes?

Answer 10

the two chromosomes of the pair, they look very similar

Question 11

What is different about sex chromosomes?

Answer 11

designated X (large), Y (small)

Question 12

What is a female sex chromosome?

Answer 12

XX

Question 13

What is a male sex chromosome?

Answer 13

XY

Question 14

What does a somatic cell go through in its life cycle?

Answer 14

interphase and mitotic (m) phase

Question 15

What is the cell cycle?

Answer 15

conventionally the interphase and mitotic phase of a somatic cell can be fit into a 24 hr cycle

Question 16

What is G0 phase of interphase?

Answer 16

cells stay in G1 phase for a long time and may not reproduce, the exit cycle and stay in G0 phase

Question 17

Give examples of body cells arrested in the G0 phase

Answer 17

skeletal muscle cell, neurons

Question 18

What are chromatids?

Answer 18

the chromosomes during the mitotic prophase become visible as a pair of identical strands

Question 19

What is a centromere?

Answer 19

it holds the chromatid pair together

Question 20

When do the nuclear envelope and the nucleolus disappear during mitosis?

Answer 20

later in prophase

Question 21

During metaphase what is aligns the centromeres of the chromatid pairs at the centre of the cell?

Answer 21

mitotic spindle

Question 22

What is the visible alignment of the chromatid pairs in the middle of the cell during metaphase called?

Answer 22

metaphase plate

Question 23

What is the main thing that happens in anaphase?

Answer 23

The chromosomes move to the opposite poles of the cell dragged from the centromeres by the spindle, so they appear V-shaped

Question 24

When does mitotic telophase begin?

Answer 24

Begins after the chromosomal movement stops

Question 25

When does mitotic telophase stop?

Answer 25

Ends when cytokinesis is completed

Question 26

What happens during cytokinesis?

Answer 26

Begins in late anaphase forming the cleavage furrow

Question 27

What is a cleavage furrow?

Answer 27

A contractile ring pulls the plasma membrane inward

Question 28

What begins once cytokinesis is completed?

Answer 28

When cytokinesis is completed, interphase begins

Question 29

What is the nuclear division of reproductive cells called?

Answer 29

The nuclear division is called meiosis, where the number of chromosomes is reduced by half

Question 30

How many chromosomes do gametes contain?

Answer 30

Gametes contain a single set of 23 chromosomes

Question 31

What types of cells are gametes?

Answer 31

Gametes are haploid (n) cells

Question 32

When does Meiosis I begin?

Answer 32

Begins after the chromosomal replication is completed

Question 33

How does prophase I differ from mitotic prophase?

Answer 33

The Prophase I (is an extended phase)

Question 34

What is a tetrad?

Answer 34

Two sisters chromatids of each homologous chromosome pair off and form a tetrad (four chromatids)

Question 35

what does crossing over result in?

Answer 35

Parts of the chromatids within the tetrads may be exchanged with one another in the process called crossing-over. • This results in a genetic recombination

Question 36

When do tetrads line up along the metaphase plate?

Answer 36

Metaphase I

Question 37

What happens during anaphase I?

Answer 37

The members of each homologues pair separate and are pulled to the opposite poles of the cell The paired chromatids do not split, they remain together in this phase

Question 38

Each resulting cell of Meiosis I has _______(_) number of chromosomes

Answer 38

Each resulting cell of Meiosis I has haploid (n) number of chromosomes

Question 39

True or false: after meiosis I each cell contains only one member of each pair of the homologous chromosomes present in the starting cell

Answer 39

True

Question 40

True or false: meiosis II is similar to mitosis

Answer 40

True

Question 41

What is the net result of meiosis II?

Answer 41

The net result of Meiosis II will be four haploid cells genetically different from the starting diploid cell

Question 42

What are the three possible destinies of cells?

Answer 42

1. Remain alive and functional without dividing 2. Grow and divide 3. Die

Question 43

What keeps the balance between cell proliferation and cell death?

Answer 43

Homeostasis keeps a balance between cell proliferation and cell death

Question 44

What within a cell can activate a protein for functioning?

Answer 44

The enzymes cyclin-dependent protein kinases (Cdk’s) within the cell can activate a protein for functioning

Question 45

What within a cell can deactivate a protein?

Answer 45

Other enzymes can deactivate a protein

Question 46

What is the activation of Cdk's at the appropriate time crucial for?

Answer 46

1. DNA replication 2. Mitosis 3. Cytokinesis

Question 47

What switches Cdk's on and off?

Answer 47

Cellular proteins call cyclins switch Cdk’s on and off

Question 48

What is apoptosis?

Answer 48

normal type of cell death

Question 49

What is necrosis?

Answer 49

pathological cell death

Question 50

What is gerontology?

Answer 50

Gerontology is the scientific study of the process and problems associated with aging

Question 51

What is geriatrics?

Answer 51

Geriatrics is the branch of medicine that deals with the medical problems and care of elderly persons.

Question 52

What is cessation of mitosis?

Answer 52

Cessation of mitosis is a normal genetically programmed event Normal cells divide only for certain number of times and then stop

Question 53

What are telomeres?

Answer 53

Telomeres are DNA sequences only found at the tips of the chromosomes • Protect the chromosomes from erosion and from sticking to one another

Question 54

What happens to telomeres after each cycle?

Answer 54

Telomeres shorten after each cell cycle

Question 55

With age why do tissues lose elasticity and stiffen?

Answer 55

With age, the immune system may start attacking the body’s cells