Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Embryology > First Exam > Flashcards

First Exam Flashcards

1
Q

Is embryology or developmental biology older

A

embryology

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How long has embryology been around for

A

centuries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How long has developmental biology been around for

A

maybe since the 70’s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the focus of embryology

A

description on what happens in an embryo

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the focus of developmental biology

A

explains why things happen throughout development

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What age range does embryology focus on

A

period from conception to 1st trimester

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What age range does developmental biology focus on

A

conception through death

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the explanation to all the changes occurring throughout development

A

gene expression changes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Every human being begins as what

A

a single diploid cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Where do the diploid chromosomes come from

A

23 from mom

23 from dad

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

As development occurred in the embryo, what process led to cell division

A

mitosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What very important thing occurred during development to change the egg into an embryo

A

cell differentiation, specialization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How do the gonads divide

A

meiosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the germ line concept

A

a continuity from one generation to the next

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

As Christians, we believe our continuity can be traced all the way back to what

A

Adam and Eve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Where does life come from

A

other than God, only existing life

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is a problem that can result in germline

A

if mutation in a germline cell, that will be passed down to all the following generations. The mutation will also be in all the embryo’s somatic cells as every cell originates from a germ line cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is a technique used to fix mutations in the germline

A

gene therapy or enhancement on the germ line

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What would gene therapy be used specifically for

A

removing disease causing genes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What would gene enhancement be used for

A

bettering performance of specific genes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the name of the mechanism used for gene therapy

A

CRISPR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What 4 things are needed for CRISPR to function properly

A
  1. errored DNA
  2. guide RNA
  3. CAS9 nuclease
  4. normal sequence
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the function of the guide RNA

A

RNA molecule that pairs up with the mistake/errored DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the function of CAS9

A

cuts mutated sections out

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the function of the normal gene sequence

A

fills in the gap where the error was

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is the biggest danger with using CRISPR

A

if the guide RNA pairs where it should not be, then the wrong gene is removed=CRISPR induced mutation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

How long is the guide RNA

A

20 bases long

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Gene editing in somatic cells leads to what

A

a cure for that person

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Gene editing in germline cells leads to what

A

prevention of disease for that family line

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is the ethical debate for CRISPR

A

they must remove more than 1 zygote and manipulate about 57 of them. CRISPR only works on a few of the ones removed and the rest are thrown away. Zygotes are embryos=personhood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is the con side of CRISPR

A

could create a new disease from an off target cut

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What are the germ cells

A

spermatogonia and oogonia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What type of cell in reference to chromosomes are spermatogonia and oogonia

A

diploid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

diploid cells have what

A

pairs of chromosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is the first step that spermatogonia and oogonia undergo

A

division by mitosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What is produced due to this division

A

two diploid cells, one that continues as a primary “cyte” and one that regenerates as a spermatogonia or oogonia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What will the primary oocytes and spermatocytes undergo next

A

meisosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What is the very first step in meiosis

A

duplicating DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

When a diploid cell duplicates its DNA, it now has how many chromosomes

A

4C (4 copies of genetic material)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Germ cells are also considered what type of cell

A

stem cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Why are germ cells called stem cells

A

because they generate new cells and regenerate themselves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What is the change that occurs in meiosis I

A

primary cytes become secondary cytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What is the order of stages in meiosis

A

prophase
metaphase
anaphase
telophase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What occurs in prophase I

A

chromatin folds into chromosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What occurs in metaphase I

A

chromosomes pair up in synapsis along the metaphase plate. Crossing over may occur between the homolog chromosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What occurs in anaphase I

A

homologs seperate and are pulled to opposite poles of the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What occurs in telophase I

A

cytokinesis occurs and nucleus reforms around the chromosomes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What are the products of meiosis I

A

two secondary cytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What type of chromosome number do the secondary cytes have

A

2C each

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

In meiosis II what is the process of change

A

secondary cytes become spermatids or eggs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

What occurs in prophase II

A

chromosomes reappear

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What occurs in metaphase II

A

chromosomes line up between cell poles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

What occurs in anaphase II

A

the identical chromosomes are seperated from each other

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

What occurs in telophase II

A

nuclei form

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

How many copies of chromosomes in the product of meiosis II

A

one

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

What are the gonad organs

A

ovaries

testes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

what two things fuse in fertilization to produce a zygote

A

sperm

oocyte

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

When are eggs ovulated

A

at metaphase I (when they are becoming primary secondary oocytes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

What is the major benefit for meiosis

A

contributes to genetic diversity among offspring

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

Why is genetic diversity good

A

God likes genetic diversity

ensures survival of a species=someone will be resistant to a disease and environmental changes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

What in meiosis/fertilization leads to genetic diversity

A

independent assortment of 23 chromosomes, crossing over between homologs, mixing of gametes during fertilization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

How many possible combos due to independent assortment of 23 chromosomes alone

A

8 million

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

With the mixing of gametes (sperm and egg) how many combinations are possible total

A

over 64 trillion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

What are risks associated with meiosis

A

non-disjunction

deletions of genes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

What is the outcome of non-disjunction

A

aneuploidies or lethal monosomies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

How does a non-disjuction occur

A

chromosomes don’t separate during division, especially in eggs as they age being held in metaphase I for a long time can result in bonds between the arms of the homologs leading to them not being able to seperate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

How does deletions of genes occur during meiosis

A

during crossing overs, as genes swap, they could delete, translocate or duplicate certain sections and lose another gene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

What percentage of fertilized eggs miscarry

A

50%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

50% of the eggs that miscarry (25% total) are due to what

A

chromosomal problems

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

The other 50% of eggs miscarried are due to what

A

hormonal problems

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

25% of the eggs that miscarry due to chromosomal problems are caused specifically by what chromosomal problem

A

aneuploidies and monosomies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

When does the timing of spermatogenesis begin in humans

A

at puberty

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

How long does spermatogenesis last in humans

A

throughout life

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

How long does it take for meiosis and sperm maturation

A

a few weeks, 72 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

How do males have sperm always available

A

different regions of the testes normally initiate spermatogenesis at different times

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

Testes contain long tubules called what

A

seminiferous tubules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

What is the function of the seminiferous tubules

A

is the region where sperm generation occurs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

Where are the least mature cells located in the seminiferous tubules

A

the periphery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

where are the most mature cells located

A

near the central lumen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

what are the least mature cells in sperm genesis

A

spermatogonia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

what are the most mature cells in sperm genesis

A

spermatozoa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q

What are the cells in order for sperm genesis from least to most mature

A 
spermatogonia
primary spermatocyte
secondary spermatocyte
spermatids
spermatozoa
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q

The edge of the seminiferous tubules contain a thick barrier called what

A

blood testis barrier

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
84
Q

what is the function of the blood testis barrier

A

protects the germline from harmful substances that could be in the blood and cause damage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
85
Q

What are some cytoplasmic changes that occur during spermatogenesis

A 
increase in number
cells get smaller
formation of acrosome
formation of flagellum
aggregation of mitochondria
condensation
synthesis of receptors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
86
Q

Why do the cells get smaller with each division

A

shedding of extra organelles and cytoplasm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
87
Q

What is the acrosome

A

a membrane bound organelle that contains enzymes and receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
88
Q

Where is the acrosome located

A

in the head of the sperm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
89
Q

Where does the flagellum originate

A

from a centriole or centrosome in the tail of the sperm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
90
Q

What is the function of the flagellum

A

enables the sperm to swim to the egg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
91
Q

Where do mitochondria aggregate

A

around the tail of the sperm in order to provide ATP to run the motor of the tail

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
92
Q

What is condensation

A

the condensing of the chromosomes into very compack nucleus (extra packing and folding)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
93
Q

Where is the nucleus located

A

behind the acrosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
94
Q

Where are the receptors

A

on the head of the sperm and on the membrane of the acrosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
95
Q

What are the two main supporting cells for sperm genesis

A

sertoli cells and interstitial cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
96
Q

What is the function of Sertoli cells

A

to move the products of meiosis closer to the central lumen and to provide nutrients for developing sperm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
97
Q

Why do Sertoli cells need to provide the nutrients

A

because sertoli cells form the blood barrier and block off nutrients that come through the blood to the developing sperm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
98
Q

What is the function of interstitial cells

A

produce testosterone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
99
Q

What is the function of testosterone

A

to stimulate development of males and inhibit development of female reproductive organs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
100
Q

When does oogenesis begin in humans

A

before birth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
101
Q

How many eggs are produced

A

1-2 million

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
102
Q

When does oogenesis end

A

menopause

103
Q

How does the level of oogenesis and sperm amount differ

A

sperm is constantly created

oogenesis gradually declines with time

104
Q

When eggs are in the process of being produced, they are stalled at what point

A

metaphase I

105
Q

How many eggs are ovulated at a time

A

1 mature egg

106
Q

When does ovulation occur

A

it is synched with the monthly hormonal cycle

107
Q

With eggs and follicles gone, what also disappears and helps push menopause

A

estrogen

108
Q

What are the goals of oogenesis

A 
provide a haploid genome
stockpile organelles
stockpile biomolecules
protect egg and embryo
incorporate a single sperm during fertilization
provide developmental signals for embryo
109
Q

What are oocytes surrounded by

A

granulosa cells

110
Q

What do granulosa cells and oocyte form

A

primordial follicle

111
Q

How do you get a women to ovulate more than one egg

A

FSH injections

112
Q

Why does providing a haploid genome become a goal for the egg

A

it is fertilized during metaphase I and needs to retain the diploid state

113
Q

How is the haploid genome ensured

A

through meiosis

114
Q

How does the egg stockpile organelles

A

uneven cytokinesis

115
Q

What does uneven cytokinesis form

A

a daughter cell with most of the cytoplasm and another daughter cell with very little cytoplasm

116
Q

What is the daughter cell without cytoplasm called

A

polar body

117
Q

Do both daughter cells contain some genome

A

yes, in first division one is 2C, and then second is 1C for polar bodies

118
Q

How do polar bodies contribute to a more ethical pre implantation genetic diagnosis

A

the polar bodies should contain identical genome to the real egg, these could be analyzed as they are unable to turn into humans in the end

119
Q

How does IVF still have ethics to it

A

women must still hyperovulate, fertilize that egg and then implant . Fertilization under IVF conditions still is harsh

120
Q

How does the egg stockpile RNAs

A

as a primary oocyte it has 4 sets of chromosomes that are available for transcription into RNA, mRNAs are stockpiled in the egg

121
Q

What about rRNA stockpiling

A

hundreds of rRNA are located on chromosomes, duplicated in a process called gene amplification

122
Q

How does egg stockpile proteins

A

female synthesizes proteins, released in bloodstream and taken up by the ooctye by endocytosis

123
Q

Why does the egg stockpile lipids

A

to form membranes

124
Q

Why does egg stockpile glycogen

A

for glucose to form ATP

125
Q

What other cells can help synthesize molecules

A

follicle cells

126
Q

What is an accumulation of the stockpile materials called

A

yolk

127
Q

The yolk contributes what most

A

to the large size of the egg

128
Q

How does the egg protect itself and the developing embryo

A

zona pellucida

129
Q

What composes the zona pellucida

A

a thick layer of glycoproteins

130
Q

Some eggs have what alternative layer protecting them

A

chorion

131
Q

When the egg is ovulated, the egg is surrounded by what other protection layer

A

follicle cells (granulosa cells)

132
Q

How does a single sperm fertilize the egg

A

receptors expressed in zona pellucida and plasma membrane

cortical granules contain enzymes to destroy sperm receptors after fertilization

133
Q

How does a egg provide developmental signals to influence cell fate

A

TFs switch certain genes on stimulating embryo development,

134
Q

What is the time it takes from primordial to ovulation

A

120 days to mature

135
Q

What must sperm undergo to become activated

A

capacitation

136
Q

What does capacitation do

A

moves the sperm from a dormant, pampered, inactive state to an activated state

137
Q

What occurs during capacitation

A

ATP production
flagellum movement
loss of coat

138
Q

What is the loss of coat do

A

expose the egg-binding proteins/receptors

139
Q

What induces capacitation

A

substances in the vagina

140
Q

How long does capacitation take

A

2-3 days

141
Q

How long do flagellum move

A

48 hours maximum

142
Q

What occurs to aid in the movement of sperm to egg

A

muscular contractions and cilia of oviducts

143
Q

Why does the sperm need aid

A

sperm don’t know where to swim to

144
Q

What also occurs to help attract the sperm to the egg

A

chemotaxis

145
Q

What is chemotaxis

A

movement of sperm toward the source of a chemical signal produced by the egg

146
Q

When are these chemical signals released

A

after ovulation

147
Q

What are the chemical sources originating from

A

granulosa cells or the fluid of the follicular antrum

148
Q

Do all eggs have the same chemical

A

no

149
Q

What does the chemical from the egg match

A

receptors on different species’ sperm

150
Q

how many sperm typically reach the egg when released in the vagina

A

100

151
Q

What are the 3 barriers of an egg

A

granulosa cells
zona pellucida
plasma membrane

152
Q

How does the sperm cross the granulosa cells

A

sperm have an enzyme that digests the ECM between the granulosa cells

153
Q

What is the enzyme that degrades the ECM between granulosa cells

A

ph20

154
Q

What also aids the sperm in getting past the granulosa cell layer

A

the flagellum helps it wriggle between to get in contact with the zona pellucida

155
Q

How does the sperm get past the zona pellucida

A

uses a receptor to bind to the receptor on the zona pellucida

156
Q

What is the name of the receptor on the sperm

A

ZRK

157
Q

Where is ZRK location on the sperm

A

head of the sperm

158
Q

What does ZRK stand for

A

Zona Receptor kinase

159
Q

What is the name of the receptor on the zona pellucida

A

ZP3

160
Q

What does the binding of the ZRK to ZP3 initiate

A

the initiating the opening of calcium channels in the sperm’s head to open

161
Q

What happens when calcium channels open

A

calcium influx

162
Q

What does penetrating the zona pellucida require

A

the acrosome reaction

163
Q

When does the acrosome reaction occur

A

front of acrosome and the plasma fuses at several points

164
Q

What does this fusing of the acrosome and PM cause

A

disintegration of the acrosome to release enzymes

165
Q

What are the enzymes released

A

proteases and glycosidases

166
Q

What do proteases and glycosidases do

A

dissolve holes in the zona pellucida by breaking down the glycoproteins

167
Q

What does the sperm do next to finish crossing zona pellucida

A

wiggle its way through

168
Q

What is the second receptor on the inside of sperm

A

Izumo-1

169
Q

What does Izumo-1 attach to

A

Juno receptor on the eggs PM

170
Q

What happens when Izumo-1 and Juno attach

A

PM will fuse, sperm becomes parn of the evv

171
Q

How many copies of chromosomes are in egg when the sperm fuses with it

A

3C total

172
Q

What must the egg do

A

get rid of 1 chromosome copy through another polar body (end of meiosis 2)

173
Q

What is formed at the end of meiosis

A

single cell

174
Q

What is this single cell called

A

zygote

175
Q

Where did most of the zygotes membrane come from

A

the egg, small bit from sperm

176
Q

Where did most of the organelles for the zygote come from

A

a few mitochondria from sperm, centrosome from sperm, rest from egg

177
Q

Sperm fusion means the egg is now what

A

egg is activated

178
Q

What does an activated egg mean

A

conception

179
Q

What events occur to complete conception

A

release metaphase block, dumping of chromosomes, programming of sperm genes
initiation of mitosis
increase of synthetic activity needed for rapid cell division
blocks to polyspermy

180
Q

How is programming of sperm genes occurring

A

sperm chromosomes released into the egg are unfolded. TFs and methylases in the egg’s cytoplasm switch on certain genes promoting development

181
Q

What are the steps to initiate mitosis

A

replication of male and female chromosomes
sperm’s centriole constructs mitotic spindles
chromosomes line up and separate
cell divides

182
Q

What increase of synthetic activity occurs

A 
synthesis of extra PM
synthesis of nucleotides
DNA replication
synthesis of histones to fold newly replicated DNA
no time for transcription
maternal ribosomes
183
Q

What are the only things being replicated

A

chromosomes

184
Q

what translates into proteins, histones, ect

A

mRNA stored by the egg

185
Q

What is polyploidy

A

where there is an extra entire set of chromosomes

186
Q

What animals are ok with polyploidy

A

fish, insects, heart and muscle cells

187
Q

Why is blocking polyspermy

A

so you don’t get polyploid

188
Q

What percentage of pregnancies are triploid

A

3%

189
Q

What is digyny

A

two sets from egg

190
Q

What is diandry

A

2 from sperm/ 1 from egg

191
Q

In mitosis is extra chromosomes a problem

A

no

192
Q

In meiosis is extra chromosomes a problem

A

yes

193
Q

What percentage of polyploidy babies are born

A

0.1%

194
Q

How is blocking polyspermy achieved

A

block and inactivate Juno receptors in PM

195
Q

What occurs first to block Juno receptors

A

membrane depolarizes

196
Q

How does membrane depolarizes

A

change in ion distribution

197
Q

Is the membrane polarized or unpolarized

A

polarized

198
Q

What is high ion concentration on outside

A

sodium

199
Q

What is high concentration on inside

A

potassium

200
Q

Does inside have greater negative or positive charge

A

negative

201
Q

Upon membrane fusion between PM and sperm what occurs

A

membrane de-polarizes

202
Q

How does the membrane depolarize

A

sodium channels open

203
Q

What happens when sodium channels open

A

sodium flood inside

204
Q

What follows sodium flooding in

A

potassium channels open

205
Q

What happens when potassium channels open

A

potassium floods out

206
Q

What happens to the charges

A

outside goes negative

207
Q

What happens when the charge becomes negative

A

the juno egg surface proteins wilt

208
Q

how long does this block last

A

1 minute

209
Q

Is the block of depolarization fast or slow

A

fast

210
Q

How fast is it

A

takes a second to start

211
Q

What is the second mechanism to help block polyspermy

A

cortical reaction

212
Q

what does cortical reaction include

A

cortical granules

213
Q

What does the cortical granules contain

A

proteases
polysaccharides
peroxidase

214
Q

When sperm binds to membrane initially, what happens

A

calcium influx

215
Q

What does this calcium influx cause

A

granules are exocytosed releasing the 3 P enzymes

216
Q

What does protease enzyme do

A

destroy Juno proteins permanently so no sperm can attach again

217
Q

What does polysaccharides do

A

absorb water between PM and the zona pellucida

218
Q

What does absorbing water do

A

causes the region to swell distancing the sperm from the egg PM

219
Q

What is the function of the peroxidase enzymes

A

cross link the zona pellucida, cementing zona pellucida

220
Q

What does cross linking the zona pellucida do

A

makes it harder for sperm to penetrate, no longer can be dissolved by acrosomal enzymes

221
Q

After all the enzymes have taken effect what occurs to the chopped up Juno proteins

A

exocytosis

222
Q

How long does it take for cortical block to initiate

A

1 minute to initiate but is permanent

223
Q

What is parthenogenesis

A

development of unfertilized eggs

224
Q

What does parthenogenesis mean

A

virgin origin

225
Q

Is parthenogenesis normal

A

in other organisms, not humans

226
Q

What other organisms use parthenogenesis

A

bees, ants, wasps,

227
Q

What are rare organisms that use parthenogenesis

A

Komodo dragons, sharks, chickens, snakes, fish

228
Q

Is parthenogenesis lethal

A

for the most part

229
Q

In humans, what does parthenogenesis cause

A

dermoid cysts in the ovary

230
Q

What is a dermoid cyst

A

egg still in ovary starts to develop

231
Q

What is seen in a developing dermoid cyst

A

teeth, hair, glands

232
Q

A dermoid cyst can also be referred to as a

A

teratoma

233
Q

Why does parthenogenesis not explain the virgin birth of Jesus

A

Jesus was not female, all progeny would have to be female

234
Q

What makes parthenogenesis rare

A

regaining a diploid state

235
Q

How would a diploid state be retained

A 
skipping second meiotic division
fusion between two haploid daughter cells
activate development
similar to molar pregnancies
egg undergoes mitosis not meiosis
236
Q

What would happen if second meiotic division was skipped

A

identical pairs of chromosomes

237
Q

What is negative part of having identical pairs of chromosomes

A

homozygous for all traits=recessive mutations are activated

238
Q

What is the fusion between two haploid daughter cells

A

polar body fuses with the egg

239
Q

What would happen if the fusion would occur chromosomaly

A

identical chromosomes

240
Q

What occurs with activated development that could occur to cause parthenogenesis

A

activate mitosis but block cytokinesis

241
Q

What is the occurrance of molar pregnancies

A

1:1000

242
Q

What is a molar pregnancy

A

egg that has no chromosomes gets fertilized with sperm

243
Q

How many copies of chromosomes would the molar pregnancy have

A

1C

244
Q

Is the molar pregnancy a cyst or an actual pregnancy

A

pregnancy

245
Q

After the 1C is released into empty egg, what happens

A

mitosis and division of cell into multiple cells

246
Q

What is the result of division in the molar pregnancy

A

overproliferation of trophoblasts

247
Q

What is the end result of molar pregnancy

A

10-15cm cluster of cysts that need removed

248
Q

How are chromosomes seperated in meiosis

A

get seperated by homologs

249
Q

How are chromosomes seperated in mitosis

A

get seperatied by identicals to create pairs of homologs

250
Q

If a primary egg undergoes mitosis instead of meiosis what occurs

A

the baby is a clone to the mom

251
Q

What is another rare way that could cause parthenogenesis to occur

A

activating egg development

252
Q

What ways may activate egg development

A

squeezing egg too much that it opens calcium channels,
heat/ oxidizing agents activate protein kinases or unblock mRNAs that lead to TF activation
needle prick or nuclear transplantation

253
Q

What does poking a hole in the egg cause it to activate

A

lets calcium in

Embryology (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions