Ch 2,3- Reproduction and Embryogenesis Flashcards
1
Q
2 Groups of mammals that birth their young differently (development wise)
A
Prototherians (monotremes) and metatherians (marsupials)
2
Q
Echidna (spiny anteater) and duckbilled platypus are examples of
A
Prototherians (monotremes) (oviparity)
3
Q
Group of mammals that encase their developing embryos within hard-shelled amniotic eggs and lay them to be hatcehd
A
Prototherians (monotremes)
Method of development call oviparity
Examples includes duck billed platypus and echidna (spiny anteater)
4
Q
Koalas and Kangaroos are called
A
Marsupials (metatherians)
5
Q
“undergoes some development in its mother’s uterus and then climbs its way out of the birth canal and into her marsupium, or pouch. ”
A
metatherian (marsupial)
6
Q
Autosomal cells in animals are said to be
A
diplod (2n)
-2 copies of each chromosome
7
Q
Germ cells in animals are
A
Haploid (n)
-only 1 copy of each chromosome
8
Q
“a specific series of phases during which a cell grows, synthesizes DNA, and divides”
A
Cell cycle
9
Q
“Derangements of the cell cycle can lead to unchecked cell division and may be responsible for”
A
Cancer
10
Q
4 stages of the cell cycle
A
G1, S, G2, M
11
Q
The first 3 stages of the cell cycle (G1, S, G2) are known as
A
Interphase
12
Q
The longest part of the cell cycle is
A
Interphase (G1 , S , G2)
13
Q
“Cells that do not divide spend all of their time in an offshoot of G1 called ”
A
G0
14
Q
The cell is simply living and serving its function, without any preparation for division in what stage?
A
G0
15
Q
Interphase chromosomes look like
A
Less condensed form (chromatin)
-Not visible with light microscopy
16
Q
2 Main things that occur during G1 stage
A
- Cell create organelles for energy and protein production
2. Cell grows
17
Q
Passage into s phase is governed by a
A
restriction point (The G1/S Checkpoint)
Is the DNA good enough to replicate?
18
Q
“the cell replicates its genetic material so that each daughter cell will have identical copies during what stage
A
S phase
19
Q
“After replication, each chromosome consists of two identical
A
chromatids
20
Q
chromatids are bound together at a specialized region known as the
A
centromere
21
Q
TF: Cells entering g2 have twice as much DNA as cell in G1
A
True
22
Q
“The term chromosome may be used to refer to ”
A
- A chromatid before s phase
- A pair of chromatids attached at the centromere after s phase
23
Q
2 checks that occur in G2
A
- Did Dna replicate correctly?
2. Are there enough organelles and cytoplasm to divide
24
Q
M stage consists of
A
Mitosis with cytokinesis
25
4 stages of mitosis
```
Prophase
Metaphase
Anaphase
Telophase
(PMAT)
```
26
In autosomal cells mitosis results in
2 identical daughter cells
27
2 Main checkpoints of the cell cycle
G1/S (restriction point)
| and G2/M
28
Main protein in control of arresting cell cycle at the checkpoints
p53
29
Checkpoint where cell is concerned with ensuring cell achieved adequate size and organelles have been properly replicated to support 2 daughter cells
G2/M
30
Molecules responsible for the cell cycle are known as
Cyclins and cyclin-dependent kinases (CDK)
31
“In order to be activated, CDKs require the presence of the right”
Cyclins
32
Name the pathway to move to the next cell cycle
1. Cyclins bind to CDK (creates an activated CDK-Cyclin complex
2. Complex phosphorylates transcription factors
3. Transcription factors promote gene transcription needed for the next state
33
“One of the most common mutations found in cancer is
mutation of the gene that produces p53 called TP53
| -Cell cycle not stopped to repair damaged DNA
34
“genes that, when mutated, actively promote cell division”
Oncogenes
35
Genes that when mutated lose their ability to regulate or pause the cell cycle
Tumor Supressor Genes
36
2 types of cancer causing genes
Oncogenes and Tumor-Suppressing Genes
37
After anaphase (Chromatids split) chromatids are called
Chromosomes
38
Meiosis results in
4 non-identical cells
39
After s phase how many chromatids and chromosomes in humans
92 Chromatids, 46 chromosomes
Organized into 23 homologous pairs
40
3 Things that happen in Prophase 1
1. Chromatin condenses into chromosomes
2. Spindle apparatus forms
3. Nuclear membrane dissaperars
4. Synapsis (homologous chromosomes come together)
41
Synaptic pairs in prophase 1 is referred to as
Tetrads
42
Crossing over happens at the
Chiasma (points of synapsis)
43
Exchanging equivalent pieces of DNA at the chiasma
Crossing over
44
“tendency for genes to be inherited together”
linkage
Broken in recombinations and increases genetic variety
45
“genes that are located further from each other physically are”
Less likely to be inherited together
-more likely to cross over
46
Advantage of sexual reproduction
Genetic diversity
47
“genes coding for alternative forms of a given trait”
Allele
48
Crossing over explains what law
Mendels second low of inheritance (independent assortment)
49
Mendels second law of inheritance is
Law of independent assortment
50
“states that the inheritance of one allele has no effect on the likelihood of inheriting certain alleles for other genes.”
Law of independent assortment (2nd law)
51
“During metaphase I, homologous pairs (tetrads) align at the ”
Metaphase plate
52
Each pair of a homologous chromosome during metaphase 1 attaches to a separate spindle fiber by its
kinetochore
53
“in meiosis, homologous chromosomes are lined up across from each other at the metaphase plate and are held by”
one spindle fiber
-in mitosis each chromosome at the metaphase from is lined up by 2 spindle fibers (one from each pole)
54
During anaphase 1 what happens
Homologous pairs separate
55
Homologous pairs separate in a process called
Disjunction
56
Disjunction (where homologous pairs separate) accounts for what law
Mendel first law
Law of segregation
57
Meiosis 2 is very similar to what
Mitosis
58
What stage is the reductional division in?
Meiosis 1
59
Events that happens in Telophase 1
Nuclear membrane forms around each new nucleous
| Cells are now haploid (n)
60
A short rest period in between cell divisions where chromosomes partially uncoil
Interkinesis
61
During anaphase______get pulled apart
Sister chromatids
62
Sex linked disorder are
X-linked
63
Males are termed
Hemizygous (only one copy of gene on ex chromosome)
64
Most x-linked disorders are
recessively inherited
65
“Females carrying a diseased allele on an X-chromosome, but not exhibiting the disease, are said to be”
Carriers
66
One notable gene on the Y chromosome
SRY Gene
(sex-determining region Y)
Codes for a transcription factor that initiates testes differentiation (male gonad differentiation)
67
A father will pass y-linked diseases to
All his sons
68
2 functional components of the tests
Seminiferous tubules and interstitial cells (Of Leydig)
69
Sperm are produced in the coiled
Seminiferous tubules
70
Noroushes sperm in the seminiferous tubules
Sertoli Cells
71
Lydig cells secrete
Testosterones and Androgens
72
“As sperm are formed, they are passed to the _______ where their flagella gain motility, and they are then stored until ejaculation”
Epididymis
73
“During ejaculation, sperm travel through the ___________ to the _______ at the posterior edge of the prostate gland.”
Vas deferens, Ejaculatory Duct (at posterior prostate)
74
Pathway of sperm through the male reproductive system
Seven Up
```
Seminiferous tubules
Epididymis
Vas deferens (also called the ductus deferens)
Ejaculatory duct
(Nothing)
Urethra
Penis
```
75
Sperm is mixed with
Seminal fluid
Produced by seminal vesicles, prostate glade, and bulbourethral glands
76
3 glands that make the seminal fluid in male reproductive system
seminal vesicles, prostate glade, and bulbourethral glands
77
Gland that contribute fructose to nourish sperm and give fluid alkaline properties
Seminal vesicles
78
“give the fluid mildly alkaline properties so the sperm will be able to survive in the relative acidity of the female reproductive tract.”
Seminal vesicles and prostate gland
79
“produce a clear viscous fluid that cleans out any remnants of urine and lubricates ”
“The bulbourethral (Cowper’s) glands ”
80
Sperm and seminal fluids are called
Semen
81
Formation of haploid sperm through meiosis
Spermatogenesis
82
Spermatogenesis occurs in the
Seminiferous tubules
83
Diploid stem cells are call
Spermatogonia (give rise to 4 spermatozoa eventually)
84
Spermatogonia (diploid stem cells) replicated in s phase, after they develop into
diploid primary spermatocytes
85
The first meiotic division in spermatogenesis results in
Secondary spermatocytes (Haploid)
86
Secondary spermatocytes (haploid) undergo meiosis II to generate
Haploid spermatids
87
When spermatids mature they become
mature spermatozoa
88
Spermatogenesis results in
4 functional sperm for each spermatogonium
89
Parts of a mature sperm
head (containing the genetic material),
a midpiece (which generates ATP from fructose)
flagellum (for motility)”
90
Midpeace of the sperm is filled with
mitochondria (generates ATP from fructose)
91
“Each sperm head is covered by a cap known as ”
Acrosome
- Derived from the golgi apparatus
- Necessary to penetrate Ovum
92
Gonads of females
Ovaries
93
Ovaries produces
Estrogen and progesterone
94
Ovaries consists of thousands of
Follicles
95
Follicles in the ovaries are
“multilayered sacs that contain, nourish, and protect immature ova (eggs). ”
96
Eggs are ovulated thru the
Peritoneal sac
-lines abdominal cavity
97
After ovulation the ova is drawn into the
Fallopian tube or Oviduct
98
External female anatomy
Vulva
99
“The production of female gametes is known as
Oogenesis
100
“By birth, all of the oogonia have already
| “undergone DNA replication and are considered
Primary oocytes (diploid)
- just like primary spermatocyte
- Arrest in prophase 1
101
Once a month one primary oocyte (2n) will complete meiosis I, producing a
secondary oocyte and a polar body
-polar body generally doesn't divide any further
102
“The secondary oocyte, on the other hand, remains arrested in _______ and does not complete the remainder of meiosis II unless _______ occurs.”
metaphase II
103
“Oocytes are surrounded by two layers:
the zona pellucid (surrounds oocyte itself) (has glycoproteins that protect oocyte and compounds for sperm binding)
and the corona radiate (outside pellucida and layer of cells around oocyte during ovulation)
104
After fertilization
“The secondary oocyte undergoes the second meiotic division to split into a mature ovum and another polar body, which will eventually be broken down. ”
105
“Upon completion of meiosis II, the haploid pronuclei of the sperm and the ovum join, creating a diploid
zygote
106
“Prior to puberty, the hypothalamus restricts production of
gonadotropin-releasing hormone (GnRH)
-triggers anterior gland to secrete FSH and LH
107
Gonadotropin releasing hormone stimulates the _______ to produce______ and ________
anterior pituitary
Follicle Stimulating (FSH) Hormone and Luteinizing Hormone (LH)
108
“produced by the testes, increases dramatically during puberty, and sperm production begins.”
testosterone
109
“FSH in males stimulates _____whereas LH causes____
Excerpt From: Kaplan. “Kaplan MCAT Biology Review: Created for MCAT 2015 (Kaplan Test Prep).” iBooks.
the Sertoli cells----triggers sperm maturation
Interstitial cells to produce testosterone
110
2 roles of testosterone
1. Develops and maintains male reproductive system
| 2. Results in development of secondary sexual characteristics
111
The ovaries produce what
Estrogen and Progesterone
112
In the embryo, estrogens stimulates
development of the reproductive tract
113
“secreted in response to FSH, and they result in the development and maintenance of the female reproductive system and female secondary sexual characteristics”
Estrogen
114
“In adults, estrogens lead to ”
“the thickening of the lining of the uterus (endometrium) each month in preparation for the implantation of a zygote.”
115
Hormone secreted by the corpus luteum
Progesterone
116
“involved in the development and maintenance of the endometrium, but not in the initial thickening of the endometrium”
Progesterone
“EStrogen EStablishes and PROgesterone PROtects the endometrium.”
117
After 3rd trimester, progesterone is supplied by
Placenta
| before it was the corpus luteum
118
What are the 3 events of the menstrual cycle
Follicular, Ovulation, Luteal Phase
119
The peak of LH marks
Ovulation
120
“The follicular phase begins when”
“the menstrual flow, which sheds the uterine lining of the previous cycle, begins”
121
“The higher concentrations of GnRH cause
Excerpt From: Kaplan. “Kaplan MCAT Biology Review: Created for MCAT 2015 (Kaplan Test Prep).” iBooks.
“increased secretions of both FSH and LH”
122
Estrogen provides negative feedback and decreases
GnRH, LH, FSH
123
“Estrogen works to regrow the endometrial lining, stimulating vascularization and glandularization of the
decidua (the thick layer of modified mucous membrane that lines the uterus during pregnancy and is shed with the afterbirth)
124
“Eventually, estrogen concentrations reach a threshold that paradoxically results in positive feedback, and GnRH, LH, and FSH levels”
Increase
LH surges at day 14 and induces ovulation
125
“After ovulation, LH causes the ruptured follicle to form the”
corpus luteum
126
The corpus lute secretes
progesterone
127
“The high levels of progesterone from the corpus lute in the Luteal phase again cause
Negative feedback on GNRH, FSH, and LH
128
“Assuming that implantation does not occur, the corpus luteum loses its stimulation from LH and
progesterone levels decrease.
Loss of high levels of estrogen and progesterone removes block on GnRH
129
“On the other hand, if fertilization has occurred, the resulting ______ will develop into a _________”
Zygote, Blastocyst
The blastocyst secretes (hCG)
130
HCG secreted by the _______ maintains the _______
Blastocyst, Corpus Luteum
hCG looks chemically similar to LH and stimulates its receptors
131
During the first trimester, what secretes estrogen and progesterone
The corpus luteum
132
After second trimester, hug levels decline because
Placenta now secretes progesterone and estrogen
| continues negative feedback for GnRH
133
Follicles mature during what phase of the menstrual cycel
Follicular phase
134
What hormone surge triggers ovulation
LH
135
“Ruptured follicle becomes ________, which secretes estrogen and progesterone to build up uterine lining in preparation for implantation; LH and FSH are inhibited”
corpus luteum
136
During menopause, because the negative feedback on FSH and LH is removed (estrogen/progesterone levels drop) the blood levels of these two hormones (FSH,LH) ________
Go up
137
Once formed, sperm gain motility in the epididymis and are stored there until ejaculation.
Epididymis
138
“a modified Golgi apparatus that contains enzymes that help the sperm fuse to and penetrate the ovum.”
Acrosome
139
“In males, FSH stimulates the ________and triggers __________”
Sertoli Cells, Spermatogenesis
140
In males LH cause the interstitial cells to produce
Testosterone
141
In female FSH stimulates development of ________ while LH causes _______
Ovarian Follicles, Ovulation
142
“From the time of birth until shortly before ovulation, all egg cells are arrested at the ”
Prophase 1 of meiosis
-Referred to as Primary oocytes
143
“At ovulation, the egg cell has completed meiosis I and is now arrested in ________as a haploid cell called a _______
Metaphase 2
| Secondary Oocyte
144
“The spindle apparatus first interacts with the kinetochore fibers near”
The end of prophase
145
“formation of the neural tube is called
Neurulation
146
fertilization usually occurs in the wider part of the fallopian tube called the
Ampulla
147
“Once the first sperm comes into direct contact with the secondary oocyte’s cell membrane, it forms a tubelike structure known as the”
Acrosomal Apparatus
148
“After penetration of the sperm through the cell membrane what happens
The cortical reaction occurs
A release of calcium ions
149
What are the 2 purposes of the cortical reaction, where a release of calcium ions occur to depolarize the cell membrane of the ovum
1. Prevents fertilization of the ovum by multiple sperm cells
2. Increase Ca2+ increases metabolic rate of the newly formed diploid zygote
150
The depolarized and impenetrable membrane is called the
Fertilization membrane
151
Form from fertilization of two different eggs released during one ovulatory cycle by two different sperm
Dizygotic or fraternal
Each develops its own placenta, chorion, and amnion
“Fraternal twins are no more genetically similar than any other pair of siblings.”
152
“form when a single zygote splits into two. Because the genetic material is identical, so too will be the genomes of the offspring.”
Monozygotic or identical twins
153
Monozygotic twins that don't divide completely
Conjoined twins
154
Monochorionic/Monoamniotic twins share the same
Amnion and chorion
155
Mono chorionic/Diamniotic twins
Have their own amnion but star the same chorion
156
Zygote undergoes rapid mitotic cell divisions in a process called
cleavage
157
Although several rounds of mitosis occur, total size of embryo
remains unchanged
158
When the embryo divides into progressively smaller cells the cell increases what 2 rations
Nuclear to cytoplasmic and surface area to volume ration
Increases area for gas and nutrient exchange
159
2 type of cleavage
Indeterminate and determinate cleavage
160
Results in cells that can still develop into complete organisms
Indeterminate cleavage
How monozygotic twins are formed
161
Results in cells that are committed to differentiating into a certain type of cell
Determinate cleavage
162
After several division the embryo becomes a solid mass of cells known as the
Morula
163
Once the morula is formed it undergoes what
Blastulation, (forms the blastula)
164
A _______ hollow ball of cells with a fluid filled inner cavity called a ________
Blastula, Blastocoel
The mammalian blastula is the blastocyst
An embryo with a BLASTed-out cavity is a blastula
165
The mammalian blastula is known as the _______ and consists of 2 noteworthy cell groups called the _______ and ________
Blastocyst
Trophoblast, inner cell mass
166
Surrounds the blastocoel and give rise to the chorion and later the placenta
The Trophoblast cells of the blastocyst
| the inner cell mass protrudes into the blastocoel (inner space) and gives rise to the organism
167
The trophoblast cells give rise to the
Chorion
168
An extra embryonic membrane that develops into the placenta
Chorion
The chorion also forms and outer membrane around the amnion
169
Microscopic fignerlike projections that penetrate into the endometrium
Chorionic villi (develop into the placenta)
170
The umbilical chord consists of
2 arteries and 1 vein
AVA
- Vein carries oxy blood with nutrients from placenta to embryo
- Arteries carry deoxy blood and waste to placenta
171
Until the placenta is functional, the embryo is supported by the
Yolk Sac (also site of early RBC development)
172
Involved in early fluid exchange between the embryo and the yolk sac
Allantois
Surrounded by the amnion
173
Umbilical chord is formed from remnant of
yolk sac and allantois
174
Thin tough membrane filled with amniotic fluid
Amnion
175
Once the cell mass implants in can begin the generation of 3 distinct cell layers
Gastrulation to a gastrula
176
Membrane invagination into the blastocoel is called the
Archenteron (later develops in the gut)
177
The opening of the archenteron is call the
Blastopore
178
In deuterosomes (like humans) the blastopore develops into the
Anus
D for Doo-doo
179
In protostomes the blastopore develops into the
Mouth
180
What are the 3 primary germ layers
Ectoderm, mesoderm, endoderm
181
The outer most layer is call the _______ it gives rise to what
Ectoderm
-Skin
-Nervous System
-Inner Ear
-Hair, Nails
-Epithelia of nose, mouth, lower anal canal
-Eyes lens
-Adrenal Medulla (cuz contains some nervous tissue)
(e for epinephrine)
182
The middle germ layer is called the ________ it gives rise to
MesoDerm
- Musculoskeletal
- Circulatory
- Excretory Systems
- Gonads
- Adrenal Cortex (M for mineralcoricoid)
- CT of digestive and respiratory
mnemonic: “means”oderm (the means of getting around as an organism, such as bones and muscle; the means of getting around in the body, such as the circulatory system; the means of getting around, such as the gonads
183
The innermost germ layer is called the ________ it gives rise to
Endoderm
- Epithelial linings of digestive and respiratory tracts
- Liver, pancreas, thyroid, bladder, distal urinary tracts
184
How do cells differentiate?
Selective genome transcription
Related to the concept of induction where one group of cell influence the fate of other nearby cells
Mediated by inducers (diffuse from the organizing cells to the responsive cells)
185
After the 3 germ layers are formed what begins?
Neurulation (development of the nervous system)
186
Whats the first step of neurulation?
1. Notochord formation
A rod of mesodermal cells (notochord) forms along axis like a primitive spin.
2. It induces overlying ectodermal cell group to slide inward to form NEURAL FOLDS---These surround a neural groove.
Fuses into a neural tube which gives rise to CNS
187
At the tip of each neural fold are
Neural crest cells
Migrate outward to form PNS (sensory ganglia, autonomic ganglia, adrenal medulla, schwann cells)
188
Neural crest cells develop into
The peripheral nervous system
189
Commitment of a cell to have a particular function in the future
Determination
But not yet actually produces products it needs to carry out functions of the cell (thats differentiation
Presence of diff amounts of specific mRNA and proteins during cleavage may result in this
Can also be by secretion of specific molecules from nearby cells called MORPHOGENS
190
Molecules that may cause nearby cells to follow a particular developmental pathway
Morphogens
191
After cell is determined, cell undergoes
Differentiation (assumes structures function, and biochemistry of the cell type
192
When a cell is _______it is committed to a particular cell lineage. When the cell _______it assumes the structure, function, and biochemistry of that cell type
Determined, Differentiates
| key concept
193
Cell that are yet differentiated or which give rise to other cells that will differentiate are known as
Stem cells
Exist in embryonic tissues as well as adult tissue
194
The tissues a particular stem cell can differentiate into are determined by its
Potency
195
Cells with the greatestt potency are called
Totipotent (includes embryonic stem cells)
Can differentiate into any cell type either in fetus or placental structures
196
These cells can differentiate into any cell type except for those found in placental structures
Pluripotent stem cells
197
Can differentiate into multiple types of cells within a particular group
Multipotent stem cells
198
As cell becomes more differentiated, the potency of the cells gets more
Narrower
Totipotent to pluripotent to multipotent
199
A cell that is induced is called
Responder
To be induced a responder must be COMPETENT (able to respond to the inducing signal)
200
4 methods of cell to cell communication
Autocrine, Paracrine, Juxtacrine, Endocrine
201
Cell to cell signaling that acts on the same cell that secreted the signal in the first place
Autocrine
202
Cell to cell signaling that acts on cells in the local area
Paracrine
203
Cell to cell signaling that don't usually involve diffusion but rather cell cell that directly stimulates receptors of the adjacent cell
Juxtacrine
204
Cell to cell signaling that involves directly secreting the hormones that travel though the blood stream to a distant target tissue
Endocrine
