Reproduction - Kaplan

Question 1

G1 stage

Answer 1

Active growth: production of organelles and protein synthesis

Main point is that cell grows in size

Checkpoint is the size ratio, making sure the DNA is in good condition for replication in synthesis phase

Question 2

Number of chromatids present in S phase

Answer 2

92 chromatids

23 pairs with a total of 46 chromosomes

Question 3

G2 stage of interphase

Answer 3

Growth in size, continued growth

Another check point: Mitosis Promoting factor

Question 4

Cyclins and CDK (cyclin dependent kinase)

Answer 4

Molecules that make sure the cell cycle functions normally. Cyclins activate CDK, which then phosphorylate transcription factors to promote genes requires for the next stage of the cycle

Question 5

Chromatin

Answer 5

Uncondensed, loose form of chromosome that exists in interphase in order for easy access by RNA polymerase during S phase

Question 6

Centriole

Answer 6

Microtubule that’s responsible for the proper segregation of DNA during mitosis

Found in centrosome and moves towards the ends during prophase to be anchored to the cell membrane.

Question 7

Kinetochores

Answer 7

Attachments points on the centromeres that connect spindle fibers and the chromosomes together

Question 8

T/F each cell undergoes a finite number of divisions before programmed death

Answer 8

TRUE

Question 9

Synaptonemal complex

Answer 9

Proteins that hold up the homologous chromosomes exchanging genetic materials (support the tetrad structure).

Question 10

Chiasma

Answer 10

The point of contact during homologous pairs’ exchange of DNA

Question 11

Linked genes

Answer 11

Genes that are closer together and likely to be crossed over together (tend to stay together)

Question 12

Crossing over in in prophase I explains what Mendel’s theory?

Answer 12

Law of independent assortment: inheritance of one allele has no effect on the likelihood of inheriting certain alleles for other genes

Question 13

Difference in metaphase in mitosis and meiosis

Answer 13

In meiosis, the homologous chromosomes randomly line up and each is held by one spindle fiber whereas in mitosis, the chromosomes are held at both ends with a total of 2 spindle fibers.

Question 14

Anaphase I of meiosis explains what Mendel’s law?

Answer 14

Law of segregation: during disjunction, each chromosome of paternal origin separates from its homologous of maternal origin and either chromosome can end up in either daughter cell

Question 15

Segregation in meiosis

Answer 15

Separation of the homologous pair of chromosomes (paternal chromosome separates from the maternal chromosome)

Question 16

Sex-determining region Y

Answer 16

Testis differentiation –> formation of male gonads

Question 17

Seminal vesicles

Answer 17

Fructose

Question 18

Prostate gland

Answer 18

Alkaline properties so sperm can survive in female gonads

Question 19

Bulbourethral glands

Answer 19

Clear viscous fluids that cleans out remnants of urine and lubricates the urethra during sexual arousal

Question 20

Sertolli cells

Answer 20

Stimulated by FSH, surround and nurture the spermatocytes and spermatids

Question 21

Leydig cells

Answer 21

Stimulated by LH, release testosterone upon stimulation

Question 22

Male diploid stem cell

Answer 22

Spermatogonia

Question 23

Mature sperm

Answer 23

Spermatozoa

Question 24

Spermatogenesis results in how many functional sperms for each spermatogonium?

Answer 24

Four

Question 25

Both spermatogonium and oogonium undergo what first?

Answer 25

Replication of genetic material - S phase

Question 26

Primary oocytes are arrested in what stage before a girl goes through her period?

Answer 26

Arrested in prophase I

Question 27

Zina pellucida

Answer 27

Layer secreted by granulosa cells that protect the oocyte and contain compounds necessary for sperm cell binding

Question 28

Corona radiata

Answer 28

Lies outside zone pellucida, layer of the a cells

Question 29

Granulosa cells

Answer 29

Cells that surround the oocyte forming zone pellucida (oocyte plus zone pellucida is a primary follicle). It’s converts an androgen secreted by LH into estrogen. The extra step to form sex hormone compared to males

Question 30

Theca cells

Answer 30

Cells that surround to form corona radiata, forming a secondary follicle. Theca cells are stimulated by LH and produce an androgen which is ultimately converted into estrogen by the granulosa cells.

Question 31

LH in males

Answer 31

Direct testosterone development

Question 32

FSH in males

Answer 32

Stimulate sertolli cells to nourish and nurture the sperms

Question 33

Estrogen

Answer 33

Secreted in response to FSH. LH stimulates theca cells to make androgen which is then converted to estrogen by the granulosa cells

**helps to regenerate the endometrium but not maintaining it
Initial thickening of endometrium

Question 34

Progesterone

Answer 34

Secreted by the corpus luteum

Development and maintenance of the endometrium; not the initial thickening of it.

By third trimester, progesterone is supplied by the placenta

Question 35

What hormone does the blastocyst release? What’s special about it?

Answer 35

Human chorionic gonadotropin hCG

Looks similar to LH, so it maintains the corpus luteum. Very critical because estrogen and progesterone are released from the corpus Luteum in the first trimester.

Question 36

What releases estrogen and progesterone in the first trimester of pregnancy?

Answer 36

Corpus luteum

Question 37

Menopause

Answer 37

Rise in FSH and LH in the blood because the negative feedback is removed

Ovarian atrophy