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

48

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

chromosomes move to opposite poles of the cell

Question 24

How are chromosomes formed during mitotic anaphase?

Answer 24

centromere split separating the chromatid pair to form the chromosomes

Question 25

When does mitotic telophase begin?

Answer 25

after chromosomal movement stops

Question 26

When does mitotic telphase stop?

Answer 26

when cytokinesis is completed

Question 27

What happens during cytokinesis?

Answer 27

begins in late anaphase forming the cleavage furrow pulls the plasma membrane inward

Question 28

What is a cleavage furrow?

Answer 28

a contractile ring that pulls the plasma membrane inward during cytokinesis, it is always perpendicular to the mitotic spindle

Question 29

What begins once cytokinesis is completed?

Answer 29

interphase

Question 30

What is the nuclear division of reproductive cells called?

Answer 30

meiosis

Question 31

How many chromosomes do gametes contain?

Answer 31

23

Question 32

What types of cells are gametes?

Answer 32

haploid (n)

Question 33

When does Meiosis I begin?

Answer 33

after the chromosomal replication is completed

Question 34

How does prophase I differ from mitotic prophase?

Answer 34

two sisters of chromatids of each homologous chromosome pair off and form a tetrad, the parts of chromatids within treads may be exchanged with one another in a process called crossing over

Question 35

What is a tetrad?

Answer 35

four chromatids

Question 36

what does crossing over result in?

Answer 36

genetic recombination which accounts for a large variety of the genetic pool of gametes

Question 37

What is crossing over?

Answer 37

part of the chromatids of two homologous chromosomes may be exchanged with one another

Question 38

When do tetrads line up along the metaphase plate?

Answer 38

metaphase I

Question 39

What happens during anaphase I?

Answer 39

the members of each homologous pair separate and are pulled to opposite poles of the cell, paired chromatids do not split, the remain together

Question 40

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

Answer 40

haploid (n)

Question 41

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 41

true

Question 42

True or false: meiosis II is similar to mitosis

Answer 42

true

Question 43

What is the net result of meiosis II?

Answer 43

four haploid cells genetically different from starting diploid cell

Question 44

What are the three possible destinies of cells?

Answer 44

remain alive and functional w/o dividing, grow and divide, or die

Question 45

What keeps the balance between cell proliferation and cell death?

Answer 45

homeostasis

Question 46

What within a cell can activate a protein for functioning?

Answer 46

enzymes cyclin-dependent protein kinases (Cdk's)

Question 47

What within a cell can deactivate a protein?

Answer 47

enzymes

Question 48

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

Answer 48

DNA replication, mitosis, cytokinesis

Question 49

What switches Cdk's on and off?

Answer 49

cellular proteins called cyclins

Question 50

What is apoptosis?

Answer 50

the normal type of cell death and does not trigger inflammation

Question 51

What is necrosis?

Answer 51

pathological cell death and results from tissue injury and triggers inflammation

Question 52

What is gerontology?

Answer 52

the scientific study of the process and problems associated with aging

Question 53

What is geriatrics?

Answer 53

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

Question 54

What is cessastion of mitosis?

Answer 54

normal cells can divide only for a certain number of times and then stop, a normal genetically progemmed event

Question 55

What are telomeres?

Answer 55

They are DNA sequences found at the tips of chromosomes, they protect the chromosomes from erosion and sticking to each other

Question 56

What happens to telomeres after each cycle?

Answer 56

shorten after each cell cycle

Question 57

With age why do tissues lose elasticity and stiffen?

Answer 57

glucose is madded to intracellular and extracellular proteins and this links adjacent proteins and with age more cross-links are formed