Part A: Lecture 2

Question 1

gametogenesis (def.)

Answer 1

meiosis when it produces gametes

Question 2

meiosis in males

Answer 2

spermatogenesis (diploid -> spermatid -> sperm)

Question 3

meiosis in females

Answer 3

oogenesis (diploid -> oocyte -> egg)

Question 4

spermatogenesis (def.) + steps (2)

Answer 4

haploid cells grow flagella to be motile
-step 1: meiosis
-step 2: maturation

Question 5

spermatogenesis begin entering meiosis at _____

Answer 5

puberty

Question 6

spermatogenesis takes how long?

Answer 6

60 days

Question 7

spermatogenesis produces __ gamates

Answer 7

4

Question 8

oogenesis produces how many gametes?

Answer 8

a single large haploid cell rather than four little haploid cells

Question 9

In humans, oogenesis produced ___ discarded cells named?

Answer 9

2 polar bodies

Question 10

oogenesis in humans start in ___ and _____

Answer 10

fetus and pauses in prophase I when DNA replicated and condensed

Question 11

oogenesis during puberty

Answer 11

-once a month, one or two cells resume meiosis, enter oviduct, and can be fertilized

Question 12

pronuclei (def.)

Answer 12

nucleus of a sperm/egg cells during the process of fertilization

Question 13

fertilization (sperm + egg)

Answer 13

sperm: 23 paternal chr.
egg: 23 maternal chr. cytoplasm and mitochondria

Question 14

fertilization cleavage timeline

Answer 14

-egg -> morula -> blastocyst

Question 15

DNA replication starts at ____ (fertilization)

Answer 15

-zygote stage

Question 16

Genes turn on at ____ (fertilization)

Answer 16

-the 4 cell stage

Question 17

zygotic genome activation (def.)

Answer 17

initiation of gene expression after fertilization at the 4 cell stage

Question 18

hatching (def.)

Answer 18

blastocyst expelled out of the zona pellucida

Question 19

implantation

Answer 19

-blastocyst enters side of uterus

Question 20

inner cells of blastocyst becomes the ___

Answer 20

embryo

Question 21

outer cells of blastocyst becomes the ___

Answer 21

membranes and placenta

Question 22

fluid cavity of blastocyst becomes the ___

Answer 22

amniotic cavity/fluid

Question 23

cells in amniotic fluid are from ____

Answer 23

the embryo

Question 24

dizygotic (non-identical) twins

Answer 24

2 zygotes (2 placenta + embryos)

Question 25

monozygotic (identical) twins (2 types)

Answer 25

• splitting at 2-cell stage: separate placentas
• splitting inner cell mass: 1 placenta

Question 26

twins are rare but one type of twins is rarer: ___

Answer 26

monozygotic twins

Question 27

embryogenesis involves ___ to make ____

Answer 27

-cell differentiation, cell division
-organs