Gametogenesis

Front 1

The ______ cells are separated away from the rest of the embryo early on.

Back 1

germ

Front 2

Mutations in somatic cells affect the germ line. True or False?

Back 2

False

Front 3

What are the 2 types of cells?

Back 3

somatic cells and germ cells

Front 4

The _____ cells carry the genetic information from one generation to the next.

Back 4

germ

Front 5

Mutations in _____ cells will not affect the next generation.

Back 5

somatic

Front 6

Mutations in ____ cells can be passed to the next generation.

Back 6

germ

Front 7

Germ cells are really good at ____ ____ and they usually divide very _______.

Back 7

DNA repair, slowly

Front 8

When germ cells divide _______, it helps to protect the integrity of the _______.

Back 8

slowly, genome

Front 9

Germ cells spend more time in the _____ phase of the cell cycle which is where ______ repairs.

Back 9

G1, repairs

Front 10

If you restrict the ____ phase of the cell cycle, then you restrict the accumulation of _______.

Back 10

S, mutations

Front 11

In nearly all animals studied to date, proteins from ____ different protein families are needed to make a germ cell.

Back 11

4

Front 12

What 2 proteins bind to mRNA and regulate the rate at which mRNAs are translated?

Back 12

Vasa and Nanos

Front 13

Which 2 proteins trigger epigenetic modifications in specific regions of the genome to silence transcription of genes located in those regions.

Back 13

Tudor and Piwi

Front 14

Epigenetic modifications

Back 14

chemical changes to the chromatin that affect gene expression but don't affect the sequence of bases (how tightly compacted or not the chromatin is)

Front 15

Vasa binds to specific mRNA and _______ their translation.

Back 15

promotes

Front 16

Nanos binds to specific mRNA and ____ their translation.

Back 16

represses

Front 17

Epigenetic modifications help make the right amount of cell _____ to push cells down the _____ cell pathway.

Back 17

expression, germ

Front 18

The cells that express Vasa, Nanos, Tutor, and Piwi therfore become _____ cells.

Back 18

germ

Front 19

Primordial germ cells (PGCs)

Back 19

precursors to sperm and egg

Front 20

When we see Vasa, Nanos, Tudor, and Piwi expressed in an embryo it is termed the ____ _____.

Back 20

germ plasm

Front 21

In some species Tudor, Piwi, Vasa, and Nanos are _____ into the ______ during ______ and then as the cell divides whatever cells inherit those proteins become the _____ cells.

Back 21

deposited, egg, oogenesis, germ

Front 22

When cells inherit the proteins associated with germ cells we say that in those eggs there was a _____ ____.

Back 22

germ plasm

Front 23

Germ plasm

Back 23

specific region of plasm in egg that carried Tudor, Piwi, Vasa, and Nanos and after development occurred any cell that inherited the plasm became a germ cell

Front 24

In mammals the Tudor, Piwi, Vasa, and Nanos are turned on after _______ has begun in a subset of ____ in the early embryo.

Back 24

development, cells

Front 25

In non-mammalian vertebrates, the 4 proteins are _____ into the egg during ______ and act as ________ ________.

Back 25

deposited, oogenesis, cytoplasmic determinants

Front 26

In amniotes, the expression of the four key germ cell genes is triggered by _______ signals.

Back 26

inductive

Front 27

In mammals, amphibians, and reptiles the four key germ proteins are turned on after ______ and right before ________.

Back 27

fertilization, gastrulation

Front 28

Because of _______ events a subset of cells turn on Tudor, Piwi, Vasa, and Nanos and these become _____ cells.

Back 28

signaling, germ

Front 29

In gametogenesis there is migration of PGCs into the developing ______

Back 29

gonads

Front 30

The cells that inherited the germ plasm acquire a unique cell expression and we call them _______.

Back 30

primordial germ cells (PGCs)

Front 31

The PGCs arise well outside where they need to be in order to ______

Back 31

function

Front 32

_______ are produced in the gonads but the PGCs arise well before there are any gonads in the ______.

Back 32

Gametes, embryo

Front 33

PGCs usually form in physical location quite _____ from gonads.

Back 33

far

Front 34

PGCs undergo ______ to get to the developing gonads.

Back 34

migration

Front 35

_______ to ______ Is one of the longer migratory pathways in any migratory cell type during embryogenesis.

Back 35

PGCs, gonads

Front 36

If PGCs end up in wrong place they can give rise to a _____ called a _________.

Back 36

tumor, teratocarinoma

Front 37

Teratocarinoma

Back 37

a tumor that has fast growing cells that randomly differentiate

Front 38

PGCs are true ______ ______

Back 38

stem cells

Front 39

During migration to the gonads the ______ are _____ cells.

Back 39

PGCs, stem

Front 40

What are the 2 requirements to be considered a stem cell?

Back 40

1. cell cannot be fully differentiated 2. when a stem cell divides at least one of the daughters has to remain a stem cell

Front 41

There is a range of stem cells depending on ______ type.

Back 41

differentiation

Front 42

Stem cells exhibit ____- _____

Back 42

self -renewal

Front 43

While PGCs are migrating they remain ____ _____ and increase the pool of ____ _____ until they reach the ______ where one daughter cell will go on to ________.

Back 43

stem cells, stem cells, gonads, differentiate

Front 44

Female mammals begin making the gametes during ________

Back 44

embryogenesis

Front 45

Males make gametes until _____ _____

Back 45

sexual maturity

Front 46

Although PGCs divide by _____, when they become a _______ (one daughter) they will switch to _____ cell division, which they might do ____ ______ or _______ ____.

Back 46

mitosis, gamete, meiotic, right away, later on

Front 47

Each chromosome replicates prior to undergoing _______.

Back 47

meiosis

Front 48

We know that a functional gamete has to be born from a ________ cell division because we cut the ______ number in half.

Back 48

meiotic, chromosome

Front 49

In meiosis cells go through the ____ phase so you end up with 2 _____ ______ per chromosome.

Back 49

S, sister chromatids

Front 50

In meosis I you separate ______ ________ and in meosis II you separate ________.

Back 50

homolog chromosomes, sister chromatids

Front 51

During meiosis, chromosome number in each cell is ______.

Back 51

reduced

Front 52

A full complement of ________ is restored during fertilization

Back 52

chromosomes

Front 53

Meiosis is important because if games are not _____ then you cannot create a ______ offspring.

Back 53

haploid, diploid

Front 54

If the offspring was not ______ then it would not ______.

Back 54

diploid, develop

Front 55

If in the beginning of Meiosis I we began with 2n and 4C then at the end of Meiosis I we would have how many n and C?

Back 55

1n 2C

Front 56

If in the beginning of Meiosis II we began with 1n and 2C then at the end of Meiosis II we would have how many n and C?

Back 56

1n 1C

Front 57

In Meiosis and Mitosis n keeps track of what?

Back 57

total DNA content

Front 58

In Meiosis and Mitosis C keeps track of what?

Back 58

sets of chromosomes

Front 59

In _____ Meiosis in continuous and in ______ a cell commits to ________ and pauses for a few years until it starts ________, and at _________ it pauses until ________ begins.

Back 59

males, females, MI, MII, fertilization

Front 60

The egg does not finish MII until after _______.

Back 60

fertilization

Front 61

Meiosis contributes ______ ________to the gametes in 2 ways.

Back 61

genetic variation

Front 62

What are the 2 ways that meiosis contributes genetic variation to the gametes?

Back 62

independent assortment and crossing over

Front 63

Independent assortment of maternal and paternal ______ during meiotic division ____.

Back 63

homologs, I

Front 64

Crossing over occurs during meiotic _____ ___.

Back 64

prophase I

Front 65

The _____ of independent assortment and crossing over are the same, but the ______ is different.

Back 65

mechanics, timing

Front 66

The point of meiosis is to generate _______ ______ in cells that go through the process.

Back 66

genetic variation

Front 67

When homologous pairs align up there are many different possible _____/_____ in Meiosis ___.

Back 67

orientations/combinations, I

Front 68

Crossing over is the shuffling of _____ material between _____ chromosomes.

Back 68

genetic, homologous

Front 69

Due to crossing over it is impossible to end up with 2 ______ with the same ______ and combinations, although they will still have the same _____.

Back 69

gametes, alleles, genes

Front 70

For sperm to be able to travel a long way in aqueous environment and reach their target (egg) they need to undergo _____ _______.

Back 70

cellular differentiation

Front 71

Sperm need a ______ for propulsion, however they cannot carry a lot of _____ or swim _____ distances. They need to get _____ of anything they don't need for journey.

Back 71

flagellum, mass, long, rid

Front 72

Eggs don't have to travel and _____ move along.

Back 72

passively

Front 73

Mammalian _____ have to carry all of the material necessary for the first rounds of ____ _____.

Back 73

eggs, cellular division

Front 74

After fertilization there is no _____ supply connecting the ____ to the female and _____ has no way of feeding itself.

Back 74

blood, embryo, embryo

Front 75

Prior to _______, all of the necessary nutrients and other material that will be needed by _____ need to be deposited in the _____ which are usually ______ in size.

Back 75

fertilization, embryo, egg, really big

Front 76

Eggs have _____ to protect it from _____ while it is waiting for ______ to occur.

Back 76

characteristics, damage, fertilization

Front 77

In spermatogenesis the _________ divide and the ones that will commit to being gametes will be called ______ _____.

Back 77

primordial germ cells, spermatic gonad

Front 78

Spermatic gonad go through a series of rapid _____ cell divisions.

Back 78

mitotic

Front 79

After each cell division the daughter cells are physically connected by a bridge of cytoplasm known as _____

Back 79

syncitium

Front 80

The syncitium forms because the ______ cell divisions are followed by ____ _____.

Back 80

mitotic, incomplete cytokinesis

Front 81

The syncitium proves to be useful because it keeps the cells in the same ______ and they can later go through later stages of _____ as a group.

Back 81

location, spermatogenesis

Front 82

When cells transition out of mitotic cell cycle and undergo ____ they are called _____ _ _____.

Back 82

meiosis, Type B spermatogonia

Front 83

When cells undergo MI we call them ____ _______ and when they undergo MII we call them ____ _______.

Back 83

primary spermatocytes, secondary spermatocytes

Front 84

After _____ is done the cells have not undergone _____ _______ and they don't look like sperm rather just a bunch of cells stuck together.

Back 84

meiosis, cellular differentiation

Front 85

Spermatids

Back 85

after the cells finish meiosis and begin the cellular differentiation process into sperm

Front 86

What are the 3 main type of cell division in spermatogenesis?

Back 86

mitotic cell division, meiosis, post-meiotic differentiation of sperm

Front 87

Cellular differentiation of sperm occur after ______ is complete.

Back 87

meiosis

Front 88

Mitochondrion make the _________.

Back 88

cytoskeleton

Front 89

A first hint for mature sperm is when the microtubule _______ is broken down and the ______ begins to organize the microtubule ____ into a long structure called a _______.

Back 89

cytoskeleton, centriole, cytoskeleton, flagellum

Front 90

_____ grow slowly and grow as a consequence of centriole reorganizing the ________.

Back 90

flagellum, microtubules

Front 91

A part of the ____ ______ buds off and it gets bigger until it sits on one side of the nucleus. This becomes the _____ ______ that sits on top of the nucleus.

Back 91

golgi apparatus, acrosomal vesicle

Front 92

The acrosomal vesicle has ____ that will break down the extra layers of the _____>

Back 92

enzymes, egg

Front 93

The ______ begin to be transported back to the _____ end of the nucleus and end up concentrated in the ______ of the sperm.

Back 93

mitochondria, back, midpiece

Front 94

The midpiece of the sperm connects the _____ to the _____ region

Back 94

flagellum, head

Front 95

________ is how you make ______ with the greatest efficiency and the greatest quantity.

Back 95

mitochondria, ATP

Front 96

The _____ is concentrated to the place where you will need ATP and the rest of the ______ ______ of the cell are pretty much shut down.

Back 96

mitochondria, metabolic processess

Front 97

Once the cell is differentiated into a sperm there is no ______, nucleotide synthesis, or any real ______ other than _____ ______ taking place in the mitochondria.

Back 97

glycolysis, metabolism, cellular respiration

Front 98

The head of the sperm remains small because there needs to be little _____ as it swims through the _________ ____.

Back 98

drag, reproductive tract

Front 99

What are the 2 main reasons for which the head region of sperm remains small?

Back 99

1. we will lose most of the cytoplasm 2. during spermatogenesis the DNA inside haploid nucleus will get packaged into smaller units

Front 100

During spermatogenesis _______ (DNA binding proteins) are switched out for _____, which results in tighter binding.

Back 100

histones, protamines

Front 101

Why do protamines result in tighter binding?

Back 101

they are more positively charged and the DNA will bind more tightly

Front 102

Meiosis in oocytes is _______ because there is 2 points where the oocyte pauses before proceeding to the next step.

Back 102

discontinous

Front 103

In females oogenesis begins during ________.

Back 103

embryogenesis

Front 104

In oogenesis the 1st meiotic arrest is where?

Back 104

early meiosis I

Front 105

In oogenesis the 2nd meiotic arrest is where?

Back 105

meiosis II

Front 106

The first meiotic arrest takes place until the female reaches ____ ____.

Back 106

sexual maturity

Front 107

The first meiotic arrest is released by _____ that trigger ________, allowing meiosis I to complete.

Back 107

hormones, ovulation

Front 108

After the first meiotic arrest there is _______ of the oocyte.

Back 108

differentiation

Front 109

What are some of the of the differentiations of the oocyte that occur after MI?

Back 109

cortical granules, egg integuments, cytoplasmic loading, and microvilli

Front 110

The second meiotic arrest is released by ______ , allowing MII to be complete.

Back 110

fertilization

Front 111

Cellular differentiation begins during the first ____ ____.

Back 111

meiotic arrest

Front 112

Cellular differentiation is a _____ ______ process

Back 112

slow ongoing

Front 113

Cytoplasmic loading

Back 113

everything necessary for first processes after fertilization needs to be stored in egg because early embryo does not have a way of getting outside nutrients

Front 114

Why is the data for mammals in regards to cytoplasmic loading not as extreme as it is from frogs?

Back 114

mammalian embryos establish a blood supply so that the embryo can get nutrients earlier

Front 115

During cytoplasmic loading there is disposition of extra ______ into the ______ _____.

Back 115

membrane, plasma membrane

Front 116

There is formation of ____ on the surface of an oocyte due to excess ______ being stored in the membrane.

Back 116

microvilli, lipids

Front 117

After fertilization the cell will divide and this requires more _____ ____ so you need extra ____ for the extra _____ _____ as the cell divides.

Back 117

surface area, lipids, surface area

Front 118

Cortical granule

Back 118

membrane bound structures derived from golgi

Front 119

The cortical granules contain ____ that help prevent _______.

Back 119

enzymes, polyspermy

Front 120

Polyspermy

Back 120

more than 1 sperm fertilizing the egg

Front 121

Enzymes that prevent polyspermy are released during ______.

Back 121

fertilization

Front 122

________ cells of the follicle produce and transfer nutrients, proteins, ribosomes into the developing oocyte during the ______ _____ _____.

Back 122

granulosa, first meiotic arrest

Front 123

All the extra stuff from the cytoplasmic loading phase comes from ____ and _____ sources.

Back 123

internal, external

Front 124

Internally, to get ready for meiosis the call has gone through the ___ phase and has twice as much ____ which means that the egg can support a lot of ____ _____ internally.

Back 124

S, DNA, protein production

Front 125

Externally there are supporting cells in the ____ that make _______connections to the developing oocyte and these supporting cells pass material.

Back 125

ovary, physical

Front 126

______ cells are the supporting cells in mammals and these pass material such as proteins, nucleic acids, organelles, mitochondria into the developing _____.

Back 126

granulosa, oocyte

Front 127

We ______ see the physical connections that are occurring between the _____ cells and the developing oocyte.

Back 127

cannot, supporting

Front 128

Egg integuments

Back 128

extra layers of material deposited outside of the egg (outside of plasma membrane of the egg) that will protect egg from being damaged in environment and/or provide a binding site for sperm

Front 129

In birds the 2 egg integuments are _____ and _____.

Back 129

vitelline, shell

Front 130

The vitelline envelope sits right on top of egg ____ _____ and helps prevent desiccation of the oocyte and acts as a ______ ______ for sperm.

Back 130

plasma membrane, binding site

Front 131

Desiccation

Back 131

to dry up

Front 132

The vitelline envelope is basically a specialized and thin _______ ____

Back 132

extracellular matrix

Front 133

The vitelline envelope is released during _____ and as it spins through the _____

Back 133

ovulation, oviducts

Front 134

The outer integument is deposited as it goes through the ______.

Back 134

oviducts

Front 135

The outer integument in birds is the _____ which provides a ________ _______.

Back 135

shell, physical barrier

Front 136

In amphibians the outermost integument is a thick gooey ______ layer that binds to a lot of ____ and the inner layer is called the _____ _____.

Back 136

polysaccharide, water, vitelline envelope

Front 137

The outer layer of the amphibian egg is different because the _____ is different.

Back 137

environment

Front 138

In mammals the innermost layer is called the ____ ____ and the outer layer is called the _____ _____.

Back 138

zona pellucida, cumulus layer

Front 139

The mammals cumulus layer is analagous to the jelly like layer of ____ because it contains a lot of ______ that bind a lot of _____.

Back 139

amphibians, polysaccharides, water

Front 140

The cumulus layer has specs of _____ cells that were trapped as they were growing.

Back 140

granulosa

Front 141

In mammals the oocyte is released with _____ cells that are trapped in the ____ layer during ovulation.

Back 141

granulosa, cumulus