Chapter Two: Reproduction

Question 1

Five stages of the cell cycle

Answer 1

G1, S, G2, M, G0

Question 2

What stages of the cell cycle are collectively called “interphase”

Answer 2

G1, S, and G2

Question 3

What happens in G1?

Answer 3

Cells create organelles for energy and protein production

Cells increase their size

Question 4

What is the “restriction point”, what cell cycle phase is it in, and what enzyme plays a major role in it?

Answer 4

The restriction point is the point at the end of G1 where DNA is checked for quality before the cell can move into S phase. P53 plays a major role in it.

Question 5

What happens in the S stage of the cell cycle?

Answer 5

DNA is replicated

Question 6

What are chromatids and what holds them together?

Answer 6

Strands of identical DNA that make up a chromosome, which are held together with centromeres.

Question 7

What happens in the G2 stage of the cell cycle?

Answer 7

Further cell growth and replication of organelles in preparation for mitosis

Question 8

What is the G0 phase of the cell cycle?

Answer 8

The cell performs its functions without preparing for division

Question 9

What mechanism regulates the cell cycle?

Answer 9

Cyclins and cyclin-dependent kinases (CDK) rise and fall during the cell cycle; cyclins bind to CDKs, phosphorylation and activating transcription factors for the next stage of the cell cycle

Question 10

Mitosis occurs in _________ cells and produces ______ genetically _______ daughter cells

Answer 10

Somatic; two; identical

Question 11

What are the four phases of mitosis?

Answer 11

Prophase, metaphase, anaphase, telophase (& cytokinesis)

Question 12

What happens in prophase? (6)

Answer 12

1) chromosomes condense
2) nuclear membrane dissolves
3) nucleoli disappear
4) centrioles migrate to opposite sides of the cell
5) spindle apparatus begins to form
6) kinetochore of each chromosome is contacted by a spindle fibre

Question 13

What happens in metaphase? (1)

Answer 13

Chromosomes line up along the metaphase plate (equitorial plate)

Question 14

What happens in anaphase?

Answer 14

Sister chromatids are separated and pulled to opposite poles

Question 15

What happens in telophase? (3)

Answer 15

1) The nuclear membrane reforms
2) Spindle apparatus disappears
3) cytoskeleton and organelles are split between two daughter cells through cytokinesis

Question 16

Meiosis occurs in ____________ cells and produces ____ ______ cells that are genetically __________

Answer 16

Germ cells/gametocytes
Up to four
Sex cells/gametes
Non-identical

Question 17

The products of mitosis are: haploid or diploid?

Answer 17

Diploid

Question 18

The products of meiosis are: haploid or diploid?

Answer 18

Haploid

Question 19

Define haploid cells

Answer 19

Those that have two copies of each chromosome

Question 20

Define haploid cells

Answer 20

Those that have one copy of each chromosome

Question 21

Meiosis is characterized by _____ round(s) of replication and ___ round(s) of division

Answer 21

One round of replication

Two rounds of division

Question 22

What are the stages of divisions in meiosis?

Answer 22

Reduction all and equational divisions

Question 23

What happens in meiosis I?

Answer 23

Homologous pairs of chromosomes (homologues) are separated from each other

Question 24

Define homologues

Answer 24

Chromosomes that are given the same number, but are of opposite parental origin

Question 25

What are the stages of meiosis? (7)

Answer 25

Prophase I, metaphase I, anaphase I, telophase I | Metaphase II, anaphase II, telophase II

Question 26

How is prophase I different from prophase in mitosis?

Answer 26

The homologues come together into tetrads and intertwine in a process called synapsis,where crossing over exchanges genetic material between two chromatids in a homologous chromosome

Question 27

Define synapsis

Answer 27

In prophase I, homologues come together in tetrads (four chromatids) to exchange genetic material in a process called crossing over

Question 28

What happens in metaphase I?

Answer 28

Homologous chromosomes line up on opposite sides of the metaphase plate

Question 29

What happens in anaphase I?

Answer 29

Homologous chromosomes are pulled to opposite poles of the cell

Question 30

What happens in telophase I?

Answer 30

The chromosomes may or may not fully decondense, and the cell may enter interkinesis after cytokinesis

Question 31

What happens in meiosis II?

Answer 31

Sister chromatids are separated from each other in a process that is functionally identical to mitosis

Question 32

Define sister chromatids

Answer 32

Copies of the same DNA held together at the centromere

Question 33

Define reductional division

Answer 33

Division that results in a reduction of chromosomes, so daughter cells are haploid whereas parent cells were diploid

Question 34

Refine equational division

Answer 34

Separation of sister chromatids without a change in polidy; I.e., you start with n parent cells and they product n daughter cells

Question 35

Two functional components of the testes

Answer 35

Seminiferous tubules and interstitial cells of Leydig

Question 36

Where do sperm develop in the testes?

Answer 36

Seminiferous tubules

Question 37

What cells nourish developing sperm?

Answer 37

Sertoli cells

Question 38

What cells secrete testosterone and other androgens in the testes?

Answer 38

Interstitial cells of Leydig

Question 39

Where do sperm gain motility and are then stored?

Answer 39

The epididymus

Question 40

What is the function of the seminal vesicles?

Answer 40

They contribute fructose to nourish sperm and produce alkaline fluid

Question 41

What glands contribute to seminal fluid?

Answer 41

The seminal vesicles, the prostate gland, and the bulbourethral glands

Question 42

What does the bulbourethral gland produce?

Answer 42

A clear, viscous fluid that cleans out any ruminants of urine and lubricates the urethra during sexual arousal

Question 43

How many sperm are produced from one spermatogonium during spermatogenesis?

Answer 43

Four haploid sperm

Question 44

After S stage, male germ cells are called:

Answer 44

Primary spermatocytes

Question 45

After meiosis I, male germ cells are called:

Answer 45

Secondary spermatocytes

Question 46

After meiosis II, male germ cells are called

Answer 46

Spermatids

Question 47

After maturation, male germ cells are called

Answer 47

Spermatozoa

Question 48

What are the three main components of a sperm cell

Answer 48

The head, the mid piece, and the flagellum

Question 49

What is an acrosome?

Answer 49

The covering of a sperm head; a modified Golgi apparatus that contains enzymes to help the sperm fuse with and penetrate the ovum

Question 50

What is the function of the mid piece of a sperm?

Answer 50

To generate ATP from fructose; contains many mitochondria

Question 51

Where are ova produced?

Answer 51

Follicles in the ovaries

Question 52

What is another name for the Fallopian tube?

Answer 52

The oviduct

Question 53

Primary oocytes are arrested in:

Answer 53

Prophase I

Question 54

Secondary oocytes are arrested in:

Answer 54

Metaphase II

Question 55

When does a primary oocyte become a secondary oocyte?

Answer 55

For ovulation

Question 56

A secondary oocyte becomes a true ovum when?

Answer 56

When it is fertilized

Question 57

What surrounds oocytes?

Answer 57

The zone pellucida and the corona radiata

Question 58

Estrogen stimulates vascularization and glandularization of the:

Answer 58

Decidua