Cell Cycle and Mitosis

Question 1

What phases make up interphase of cell cycle?

Answer 1

G1 S G2

Question 2

What phase are cells that are not dividing in?

Answer 2

G0

Question 3

Are chromosomes visible during interphase and why?

Answer 3

No because less condensed as chromatin

Question 4

What organelles are created during G1?

Answer 4

Cells for energy and protein production

Mitochondria, ribsomes, ER

Question 5

What happens during S phase?

Answer 5

Replication of genetic material - each chromosome will consist of two sister chromatids

Question 6

What binds the two sister chromatids together?

Answer 6

Centromere

Question 7

What happens during G2?

Answer 7

Check to make sure there enough organelles and that DNA was replicated properly

Question 8

What is cytokinesis?

Answer 8

Split cytoplasm and organelles between daughter cells

Question 9

Four phases of mitosis?

Answer 9

Prophase
Metaphase
Anaphase
Telophase

Question 10

Which protein controls the checkpoint between G1 and S and what is it looking for?

Answer 10

p53 - looking that DNA is not damaged before it is replicated

Question 11

What primary molecules are responsible for the cell cycle?

Answer 11

Cyclins and CDKs

Question 12

What happens during prophase?

Answer 12

Condense chromatin into chromosomes
Centrioles go to opposite sides of the cell - create spindle fibers of microtubules
Nuclear membrane dissolves

Question 13

Aster

Answer 13

Anchor the centrioles to the cell membrane

Question 14

During which phase does the nuclear membrane dissolve?

Answer 14

Prophase

Question 15

What happens during metaphase?

Answer 15

Kinectochore fibers interact with spindle apparatus to align the chromosomes at the metaphase plate

Question 16

What happens during anaphase?

Answer 16

Centromeres split so each chromatid has its own - sister chromatids separate
Kinetochore fibers shorten to pull sister chromatids to opposite ends of the cell

Question 17

What happens during telophase?

Answer 17

Reverse of prophase -
Spindle apparatus disappears
Nuclear membrane reforms
Chromosomes uncoil into chromatin

Question 18

Why is meiosis I called reduction division?

Answer 18

Homologous chromosomes are separated into haploid daughter cells

Question 19

Why is meiosis II called equatorial division?

Answer 19

Separation of sister chromatids

Question 20

Mendel’s second law

Answer 20

Inheritance of one allele has no effect on the likelihood of inheriting another allele

Question 21

When does crossing over occur?

Answer 21

Prophase I

Question 22

Draw mitosis

Answer 22

Draw

Question 23

Draw meiosis

Answer 23

Draw

Question 24

Hemizygous

Answer 24

Males only have one X chromosome so they will express any sex-linked disorders

Question 25

Carrier

Answer 25

Woman with one copy of a sex-linked disorder

Question 26

What important gene does the Y chromosome have?

Answer 26

SRY gene - sex-determining gene that causes gonads to differentiate into testes

Question 27

Where do sperm develop?

Answer 27

Seminiferous tubules

Question 28

Where are the seminiferous tubules?

Answer 28

Testes

Question 29

What are sertoli cells?

Answer 29

Nourish seminiferous tubules

Question 30

What are male sex hormones as a group called?

Answer 30

Androgens

Question 31

What secretes testosterone?

Answer 31

Cells of Leydig

Question 32

Where are the testes located?

Answer 32

Scrotum

Question 33

Where are sperm stored?

Answer 33

Epidiymis

Question 34

What is the path of sperm during ejaculation?

Answer 34

Vas deferens -- ejectulatory duct -- urethra -- penis

Question 35

What nourishes sperm?

Answer 35

Seminal vesicles

Question 36

What produces alkaline fluid for the sperm and why is it necessary?

Answer 36

Seminal vesicles and prostate gland, female reproductive tract is acidic

Question 37

Bulbourethral glands

Answer 37

Produce clear fluid that cleans out urine and libricates urethra during sexual arousal

Question 38

What is semen?

Answer 38

Sperm and seminal fluid

Question 39

Which part of sperm contains genetic material?

Answer 39

Head

Question 40

Acrosome

Answer 40

Modified golgi on the sperm head that allows for ovum penetration

Question 41

Which part of sperm contains a lot of mitochondria?

Answer 41

Midpiece

Question 42

Where are eggs produced?

Answer 42

Follicles

Question 43

What hormone is released at the start of puberty?

Answer 43

Gonadotropin-releasing hormone (GnRH)

Question 44

What releases GnRH?

Answer 44

Hypothalamus

Question 45

What hormones are released as a results of GnRH?

Answer 45

``` Follicle stimulating hormone (FSH) Lutenizing hormone (LH) ```

Question 46

What releases FSH and LH?

Answer 46

Anterior pituitary gland

Question 47

How to FSH and LH interact in male sexual development?

Answer 47

FSH - stimulate sertoli cells and sperm maturation | LH - increase testosterone production

Question 48

Male secondary sexual characteristics

Answer 48

Facial and axillary hair Deep Voice Increased muscle and bone mass

Question 49

What do FSH and LH do in female sexual development?

Answer 49

FSH - estrogen secretion | LH - progesterone secretion from corpus luteum

Question 50

What is the corpus luteum?

Answer 50

Remains of the ovarian follicle following ovulation - secretes progesterone

Question 51

What is estrogen responsible for?

Answer 51

Development and maintenance of reproductive system, secondary sexual characteristics, and thickening of endometrium

Question 52

What is progesterone responsible for?

Answer 52

Development and maintenance of endometrium but not initial thickening

Question 53

Follicular phase events and hormone levels

Answer 53

Menstrual flow - GnRH increases which leads to increased production of FSH and LH to develop ovarian follicles

Question 54

Ovulation events and hormone levels

Answer 54

Estrogen peaks and results in positive feedback, leading to GnRH FSH and LH spike - LH spike induces ovulation

Question 55

Luteal phase events and hormone levels

Answer 55

LH causes the follicle to form the corpus luteum and secrete progesterone, which provides negative feedback on GnRH LH and FSH so only one egg ovulates

Question 56

Menstruation

Answer 56

Progestone levels decline and lining is lost

Question 57

Do estrogen and progesterone stimulate or inhibit GnRH?

Answer 57

Inhibit

Question 58

hCG

Answer 58

Human chorionic gonadatropin - secreted if a blastocyst implants in uterine lining and is very similar to LH to maintain corpus luteum

Question 59

What happens to hormone levels during menopause?

Answer 59

FSH and LH increase because negative feedback loop is removed