Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Biology 200-3 > Midterm 3-2 > Flashcards

Midterm 3-2 Flashcards

(90 cards)

Start Studying
1
Q

What does it mean for cells to be differentiated

A

Cells become specialized or differentiated in response to the expression of specific sects of genes

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

What drives cell development

A

cell proliferation, cell-to-cell interactions and communication, cell differentiation, cell movement and cell expansion, and programmed cell death

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

To what extent is cell division regulated

A

(this is cell proliferation or mitosis) and it is tightly regulated to the location of amplifying cell numbers in an organism, the timing of this process, and the extent of cell division at particular locations

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

Since cells can stimulate the growth of others, what controls this

A

Receptor proteins mediate these social controls over the cell cycle

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

What are stem cells

A

This is a small subset of cells that are not yet differentiated that can create a large amount of other cells if necessary. (They remain undifferentiated)

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

What is the basic process of cell signaling

A

Cells communication with neighboring cells via contact points between the cells, and secrete small signaling molecules that bind to receptor proteins in the membranes of cells that are susceptible to that signal

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

What happens when a receptor is activated

A

Signal transduction, where the binding of the receptor activates a series of signaling processes within the recipient cells that leads to changes in gene expression or cell physiology

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

What is cell differentiation

A

Although DNA remains unchanged, the cell changes structurally and functionally. It does this by altering gene expression which generates differentiation

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

What is cell movement

A

Movement from one region of the embryo to another

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

What is gastrilation

A

organization of a mass of cells into three types of embryonic tissue. (Cell movement her is key)

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

What is programmed cell death

A

The preprogramed loss of specific cells that are later discarded during development (Super important)

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

What is apoptosis

A

also the regulated process of cell destruction. It is different from programmed cell death because it is happening in normal functioning cells as a result of mutation, infection or environment

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

What is involved in apoptosis and Programmed cell death

A

protease and DNase-mediated process of destroying cellular protein and DNA: breaking the cell into small vesicles that can be consumed by neighboring cells. (helps get rid of abnormal cells)

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

Contrast cell movement with cell expansion as these terms are related to the development of structures within a unicellular organism

A

Cell movement happens during early development (germ layer formation), while for cell expansion, this usually happens in plants where the cells are fixed and it needs to build a structure

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

What enzymes are important in the process of programmed cell death (or apoptosis)

A

Enzymes that destroy cellular macro molecules; DNases, RNases, proteases

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

Do differentiated cell have genetic equivilence

A

Differentiated adult tissue(for plants) retain all the genetic information necessary to generate a complete plant and are genetically equivalent to stem cells

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

What is nuclear transfer and what did researchers hypothesize about it

A

When a nucleas of a differentiated cell is transplanted into an unfertilized egg. The researchers hypothesized that if there is no change in genomic DNA content of a differentiated cell, then the transferred nucleus should enable the normal development of a complete individual

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

What is tissue differentiation

A

it it not reversible and it is when there is differential gene regulation in different cell types

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

What are hormones

A

inter cellular signaling molecules secreted from cells that travel through the organism to act on distinct target cells

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

What kind of effects do hormones have

A

big effect on target cells and the organism as a whole

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

How does hormone structure affect signaling

A

whether they can diffuse through the membrane or no allows them to attach to specific cells. their structure affects how the message is recieved

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

What must happen for a signal to affect a target cell

A

hormones plus other cell must bind to the receptor molecule of the cell to affect it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What does same receptors allow tissue to do

A

When different cell respond to the same signal it is because they have the same receptor. This allows for great control of cell activities throughout the unicellular organim

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

How are receptors dynamic

A

The number of receptors or its ability to bond are dynamic and can change over time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
How can receptors be blocked
drugs can bind to the receptors physically blocking it
26
What are lipid soluble signals
signals that can diffuse through the membrane and the receptor to is are in the cellign
27
What are signal receptors
Proteins that change their conformation and activity when a hormone binds to them (this is key in cell cell signaling because it means that the cell has received the signal
28
How do cells respond once a lipid soluble signal is recieved
lipid soluble signals can be processed directly
29
What is signal transduction
(for non lipid soluble signals) when a series of events convert the hormone signal from its original extracellular chemical form to a new intracellular form
30
What does amplification allow
small hormone concentrations to cause large cell responses
31
What is a secondary signal
this is after a receptor binds to a plasma membrane receptor causing a secondary signal which involve many ions or molecules that is an amplified version of the signal
32
Why are steroid receptors located inside cells, whereas most other hormone receptors are located on the plasma membrane
They are lipid soluble
33
What is a phosphorylation cascade
something that amplifies the original signal and directs a cell response
34
What helps increase speed of phosphorylation cascades
the proteins for this are often kept close together alowing them to quickly affect each other
35
in signal response, what can affect cell activity
secondary messengers and/or phosphorylation cascades by altering the gene expression and/or by activating or deactivating existing cell proteins
36
What is signal deactivation
when there is a rapid response followed by equally rapid response elimination to ensure that cells remain sensitive to the receptor
37
How are secondary messengers deactivated
phosphatases, an enzyme that removes phosphate groups from proteins, it is always ready
38
How does crosstalk work
since cell can recieve multiple signals at a time, this is when signal transduction pathways for there various signals cross and connect to form a network of possible cell responses. Part of one pathway can either induce or stimulate another response that was produced, increasing or decreasing a cells respoonse
39
what is crosstalk
integration of many cell signals to produce an integrated cell response
40
Why is signal deactivation important? Generally speaking, what might happen if a signal was not deactivated
Because if it continuously produced the signal, its sensitivity for that signal goes down next time making the cell unable to respond to the signal. this allows cells to remain responsive
41
What is fertilization
the union of one sperm with one egg to generate a diploid one-celled embryo
42
What is gametogenesis
the formation of gametes in the reproductive organs. Gametes are haploid, containing 1n DNA content
43
What is the sperm cell composed of
a haploid genome with a head containing acrosome, centriole, midpiece containing mitochondria and a tail
44
what is the acrosome
it is in the head of the sperm that contains a mixture of hydrolytic enzymes involved in degrading specific components of the egg cell wall
45
what is the centriole
It is in the sperm neck region, it is a small hollow, cylindrical structure made of microtubule fibrils
46
How does sperm move
It stores mitochondria so the movement depends on the sperms ability to produce ATP
47
What is a flagellum
basically a propeller on the sperm made of many microtubules allowing the sperm to move quickly
48
What comprises the animal egg cell
it has a cytosol enriched with nutrients as well as several structural components that regulate the process of fertilization
49
What is the yolk/yolk granules
a structure in the egg cytosol that is packed with proteins and lipids/fats for energy and biosynthesis of the early embryo. It provides all the nutrition until the placenta is formed
50
what is the vitelline envelope
a fiberous structure surrounding the cell membrane and lying beneath any associated gelatinous layers (egg jelly, zona pellucida)
51
What are the cytoplasmic determinants
proteins and key mRNA molecules that are key regulators of early development in many animals (excluding mammals). Segregation of these molecules during cleavage controls key processes leading to cell differentiation
52
What are cortical granules
small vesicle based organelles that contain enzymes that are activated upon fertilization to prevent polyspermy
53
How is the sperm recruited to the egg
by an attractant that is present in the egg coat that slowly diffuses out to the sea water. This attractant is a small protein that is recognized by receptor proteins in the sperm (chemoattraction)
54
Where does the sperm first bind to
the outer jelly coated layer of the egg
55
When/where is the acrosome released
upon direct contact between the sperm head and the egg cell, the acrosome releases its contents from the sperm head
56
what does the acrosome do to the eggs
it has a mix of hydrolytic enzymes that are released on the egg that degrade the gelatinous layer allowing the sperm to penetrate the egg with the help of the sperm tail moving forward
57
what is the acrosomal process
as the acrosomal proteins are released, a structure is built on the sperm head by polymerization of actin proteins, this structure is called the acrosomal process which mediates the fusion of sperm cell membranes
58
What happens when the egg fuses to the membrane
the sperm nucleus enters the cytosol, eventually fusing with it to generate the zygote with a 2n chromosomal content
59
Can sperm bind to any egg
No, the egg is only fertilized by the sperm of its own species
60
what is fertlizin
a compound on the sea urchin egg that appeared to bind sperm in a species specific manner. the researcher predicted that there was a corresponding protein on the surface of the sperm cells and that it bound to fertilizin in a lock and key manner
61
What is bindin
A protein on the surface of the egg that allowed only species specific sperm to bind to the species specific egg
62
How is egg-sperm interactions species specific
it is all due to the presence of bindin proteins in sperm and the fertilizen receptors in eggs. These proteins bind tightly to enable fertilization but are very selective, binding to each other only if each protein originated from the same species
63
what happens when more than one sperm fertilizes an egg
a genetic disaster that makes an unsurvivable embryo
64
What inhibitor acts rapidly after fertilization and how?
Ca2+ which is released emediatly after fertilization to create the fertilization envelope. This results of fusion of cortical granules with the egg-cell membrane that will release its contents into the extracellular matrix
65
What do these cortical granules contain that could inhibit additional fertilization
Protease, a large amount of solutes
66
What is protease
They break down proteins accociated with the egg-cell wall including receptor proteins which inhibits the binding of other sperm
67
How do solutes inhibit more fertilization
a high concentration will alter the gradient causing a rush of water into the cell form the outside
68
What does the influx of water do to the egg for fertilization
it makes a fluid filled space between vitallian envelope and cell membrane creating a barrier for further fertilization. That wall created is call the fertilization envelope
69
What is the difference between mammalian and sea urchin fertilization
mammal eggs do not produce a fertilization envelope because they do not release the proteins that modify the receptor glycoproteins, which causes the release of any additional sperm that is bound to the zona pellucida
70
What is gametogenesis
Mitotic cell division, meiotic cell divisions, and developmental events that result in the production of male and female gametes. this process occurs in a sex organ, or gonad, that male gonads are called testes and the female gonads are called ovaries
71
What happens in the male and female gonad
Diploid cells called spermatogenia and oogenia divide by mitosis to generate cells that undergo meiosis
72
How does oogenesis happen
it starts with diploid cells that become primary oocytes. The oocytes then undergo meiosis to produce secondary oocytes to ootid, that eventually mature into an egg
73
What is the Zona pellucida
Humans and mammals produce eggs that are surrounded by the vitelline envelope
74
What is cleavage
rapid cell division that follows fertilization to create a blastula. It is like mitosis only more rapid and there is no increase in size
75
What is a blastomere
the cells generated after cleavage
76
What is a blastula
once cleavage is complete, this is what the embryo is referred to as
77
Is all cleavage the same
No, it occurs in various patterns depending on the species of the embryo
78
referring to cleavage, what are the cytoplasmic determinants
they are the regulatory molecules located at specific regions of the egg cytoplasm. During cleavage, there determinants end up within specifically located sub-populations of blastomeres
79
what is the process of cleavage in mammals
this happens once the oocyte is fertilized. Cleavage will create a blastocyte that will be made up of a thin layer of trophoblast cells on the exterior which surrounds a group of cells known as inner cell mass. At the center will be a fluid fill cavity called a blastocoel. The trophoblast will later form the placenta for the embryo
80
What do morphogens do
They set up the body axes. They are small signaling molecules that are produced at a particular site at the embryo. When they diffuse into the cell, they create a concentration gradient. Morphogen synthesis is at the highest gradient
81
What does the concentration of morphogen allow cells to do
Cells can determine their location, and thus their role in development, by the concentration of various morphogens that bind to their morphogen receptors
82
How is morphogen impact time dependent
An embryo establishes the patterns of its body plan sequentially over time, and thus the entire process requires both spacial regulation and time-dependent signaling processes
83
What does bicoid do
They hypothesized that the protein encoded by this gene would function as a diffusible morphogen, regulating the development of anterior structures in the fruit fly embryo
84
What did the bicoid genes show us
maternal effect inheritance where the phenotype in the larvae is due only to the mother's genotype. If the mother lacks a copy of say the bicoid gene, so will the embryo. The mother is responsible for providing functional cytoplasmic determinants
85
What is in situ for
to localize specific mRNA. if an mRNA is critical for development there should be a high concentration of it in a specialized area
86
How do you do in situ
use a label probe to screen mRNA and thus find the mRNA region
87
What did in situ find out about bicoid
bicoid mRNA was found in the anterior of the egg cytoplasm. This mRNA is from the mother and it is present at fertilization as a cruciall cytoplasmic determinant
88
What is the gradient hypthesis
the gradient of bicoid protein was key in establishing the anterior and posterior axes within the embryo. High concentration of bicoid=anterior development, low = posterior development
89
what strongly supported the bicoid hypthesis
when the researchers injected bicoid mRNAs into wild-type embryos, anterior was always developed at the site of injection
90
How is bicoid a transcription factor
it binds to DNA and regulates expression of genes that are vital to anterior development

Biology 200-3 (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions