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Molecular Biology > Block 4 Review > Flashcards

Block 4 Review Flashcards

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AP® Biology flashcards Biology 101 flashcards
1
Q

The ectoderm is the precursor for what structures?

A

nervous system and epidermis

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2
Q

The precursor of gut, lung, and liver is the what?

A

endoderm

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3
Q

The precursor of muscles and connective tissue is the what?

A

mesoderm

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4
Q

What part of the DNA provides instructions for producing a multicellular animal?

A

non-coding regulatory DNA

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5
Q

DNA contains regulatory elements that serve as binding sites for what?

A

gene regulatory proteins

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6
Q

In most organisms, coding sequences in DNA are ___

A

similar

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7
Q

What type of DNA sequences provide uniqueness to organism?

A

non-coding sequences

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8
Q

Cells make developmental decisions long before they show any outward signs of ____

A

differentiation

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9
Q

cells that are fated to develop into a specialized cell type despite changes in environment are called ____

A

determined

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10
Q

cells that can change rapidly due to alterations in environment are called ____ _____

A

completely undetermined

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11
Q

cells that have some attributes of a particular cell type but can change with environment are called ____

A

committed

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12
Q

Most important environmental cues are signals from where?

A

neighboring cells

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13
Q

Define inductive signaling

A

induction of a different developmental program in select cells in a homogeneous group leading to altered character

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14
Q

Few cells closest to the source take on induced character. Why?

A

signal is limited in time and space

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15
Q

What are the two types of signals in inductive signaling?

A

short range: cell-cell contacts

long range: substances that can diffuse through the extracellular medium

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16
Q

A long range inductive signal that imposes a pattern on a field of cells is called what?

A

a morphogen

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17
Q

morphogens exert graded effects by forming ___ of different concentrations

A

gradients

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18
Q

Each concentration of morphogen can direct the target cells into a different ____ pathway

A

developmental

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19
Q

What are morphogen gradients formed by? (2 things)

A

localized production of an inducer; localized production of an inhibitor

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20
Q

A positive feedback system stars off ___ and ___

A

homogenous and symmetrical

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21
Q

true or false?

The environment of a positive feedback system imposes weak asymmetry

A

true

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22
Q

Positive feedback involving intracellular signals also make cells ___

A

polarized

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23
Q

Broken asymmetry is “___ or ___” phenomenon

A

all or nothing

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24
Q

true or false?

postive feedback is irreversible

A

true

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25
Q

Asymmetry is generated by ___ feedback

A

postive

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26
Q

What is phase 1 of neural development?

A

different cell types develop independently at different locations in embryo according to local program and are unconnected (genesis of neurons)

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27
Q

What is phase 2 of neural development?

A

axons and dendrites grow out along specific routes setting up a provisional but orderly network of connections between various parts of the system (outgrowth of axons and dendrites)

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28
Q

What is phase 3 of neural development?

A

continues into adult life, connections are adjusted and refined through interactions with distant regions via electric signals (refinement of synaptic connections)

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29
Q

Tip of axon/dendrite has an irregular, spiky enlargement called what?

A

growth cone

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30
Q

Growth cone crawls through surrounding tissue, trailing the axon or dendrite behind. One of the growth cones starts migrating fast and develops __-____ proteins which form an ___

A

axon-specific; axon

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31
Q

growth cone behavior is dictated by its ___ machinery?

A

cytoskeletal

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32
Q

growth cones throw out ___ and ___

A

filopodia and lamelopodia

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33
Q

Monomeric GTPases __ and ___ control the assembly/disassembly of actin filaments, which control movement of growth cone

A

Rho and Rac

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34
Q

growth coins exploit two major cues to find their way. What are they?

A

extracellular matrix environment; chemotactic factors

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35
Q

Netrin, Slit, and Semaphorin are examples of what?

A

chemotactic factors

netrin is attractant; slit and semaphorin are repellents

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36
Q

axonal growth cone reach target cells, halt, communicate and make ___ with target cells

A

synapses

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37
Q

What regulates which growth cones synapse and where?

A

signals from target tissue

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38
Q

Target cell produces limited amount of ____ factors needed for survival

A

neurotrophic

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39
Q

Activity dependent synaptic remodeling depends on what?

A

electrical activity and synaptic signaling

40
Q

“Neurons that ___ together, ___ together”

A

fire; wire

41
Q

Name layer of skin:

made of epithelial cells; forms the outer covering of skin; creates water barrier; continuously repaired and renewed

A

epidermis

42
Q

name layer of skin:

second layer; rich in collagen; provides toughness

A

dermis

43
Q

name layer of skin:

fatty subcutaneous layer

A

hypodermis

44
Q

Starting from the outermost cell layer, name all of the cell layers/types

A

squame flaking off; keratinized squames; granular cell layer; prickle cell layers; basal cell layer; basal lamina; connective tissue of dermis

45
Q

epidermis is a stratified layer made of ___

A

keratinocytes

46
Q

the basal cell layer is attached to what?

A

basal lamina

47
Q

Prickle cells have numerous desmosomes that attach tufts of ___ filaments

A

keratin

48
Q

granular cells are sealed together to form what?

A

waterproof barrier

49
Q

granule cell layer forms a boundary between inner metabolically active strata and outer dead epidermis. true or false?

A

true

50
Q

true or false?

outermost layer is called squame, flattened dead cells densely packed with keratin but with no organelles

A

true

51
Q

are basal cells dividing cells?

A

yes

52
Q

time for birth of cell in basal layer to shedding from surface is how long?

A

1 month

53
Q

Stem cells provide an indefinite supply of fresh ___ cells to epidermis

A

differentiated

54
Q

The following are characteristics of what:
not terminally differentiated; can divide without limit; undergo slow division; when divide, give rise to 1 cell with stem cell characteristics and the other with the ability to be differentiated

A

stem cells

55
Q

True or false?

stem cells are not tissue specific

A

false, they are

56
Q

to maintain a steady pool of stem cell production, precisely ___% of daughter cells must remain as stem cells

A

50

57
Q

Explain divisional asymmetry

A

asymmetric division may create 2 cells, one with stem cell characteristics and another with factors that give it the ability to differentiate

58
Q

Explain environmental asymmetry

A

division makes 2 identical cells but environmental may influence/alter 1 cell

59
Q

true or false?

in regards to regulation of epidermal stem cells, contact with basal lamina controls numbers of stem cells

A

true

60
Q

loss of contact with basal lamina triggers what?

A

terminal differentiation

61
Q

proliferative potential directly correlates with expression of what? (helps mediate adhesion to basal lamina)

A

B1 subunit of integrin

62
Q

Mixed with stem cells are other cells that divide frequently. what are these cells called?

A

transit amplifying cells

63
Q

True or false?

transit amplifying cells can divide an unlimited amount of times

A

false; duh. that would be cancer. divide for a limited number of times

64
Q

The free surfaces of cilia on olfactory receptors have ___ receptor proteins

A

odorant

65
Q

what type of receptors are olfactory receptors?

A

G protein coupled

66
Q

Odorant receptor genes:

___ in a dog
___ in humans

A

1000; 350

67
Q

Each neuron expresses only one gene, enabling the cell to respond to only one what?

A

class of odorant

68
Q

____ features of the odorant recognized by the receptor

A

structural

69
Q

The activation of the G protein that is coupled with the olfactory receptor leads to an influx of sodium and calcium into the the cell which generates what?

A

action potential that is sent to brain

70
Q

what are the relay stations in the brain called?

A

glomeruli

71
Q

where are glomeruli located?

A

olfactory bulbs - one on each side of the brain

72
Q

how many glomeruli are in one bulb in a mouse brain

A

1800

73
Q

individual olfactory neurons survive for how long?

A

only a month

74
Q

Regeneration of olfactory receptor cells is one of the only few instances of adult ____

A

neurogenesis

75
Q

Epidermal cells: A matrix of ___ and ___ made into a sheet lined with a thin membrane of silicone on the outside can form an artificial matrix

A

collagen and glycosaminoglycan

76
Q

___ and ____ ___ from patient’s tissue migrate towards artificial skin and reform the connective tissue underneath

A

fibroblasts; blood capillaries

77
Q

What are the two places in the brain where stem cells are prevalent?

A

ventricles: migrate to olfactory bulb
hippocampus: involved in learning and memory

78
Q

cultures established from dissociated brain tissue show ____ which are clusters of neural stem cells

A

neruorspheres

79
Q

neurospheres produce both ___ and ___ cells

A

neurons and glial cells

80
Q

neural stem cells grafted into adult brain have remarkable ability to adjust their ___ and ___ to match their location

A

behavior and function

81
Q

grafted cells produce neurons that connect with host neurons and give rise to ____ that secrete ___ ____

A

glial cells; myelin sheath

82
Q

Retinoid acid causes stem cells to develop into what?

A

adipocyte, neuron, or smooth muscle cell

83
Q

IL-3 and IL-1 cause stem cell to develop into what?

A

macrophage

84
Q

fibroblast growth factor causes stem cell to develop into what?

A

astrocytes and oligodendrocytes

85
Q

The ability of a cell to give rise to all cells of an organism, including embryonic and extra embryonic tissues is called what?

A

totipotency

86
Q

The ability of a cell to give rise to all cells of the embryo and subsequently adult tissues is called what?

A

pluripotency

87
Q

The ability of a cell to give rise to different types of a given lineage is called what?

A

multipotency example: blood stem cells can become red or white

88
Q

Founder stem cells define the size of large final structures. If the adult organ needs to be renewed, founder stem cells can divide as stem cells giving rise to one daughter stem cell and a set of cells that have a set number of what?

A

transit amplifying divisions

89
Q

The immortal stand hypothesis ensures integrity of the genome because the template is never lost. true or false?

A

true

90
Q

Embryonic stem cells are derived from the ___ stage of embryo

A

blastocyst

91
Q

embryonic stem cells give rise to disorganized growths called ____

A

teratomas

92
Q

what are some limitations of embryonic stem cell usage?

A

tissue rejection; genetic instability

93
Q

IPS : inducing pluripotent stem cells involves what?

A

supplying transcription factors to a somatic cell to trick it into thinking its a stem cell

94
Q

Describe somatic cell nuclear transfer

A

Take an egg cell and remove nucleus. Fuse it with a somatic cell. Stimulate cell division - blastocyst forms with DNA from somatic cell. Extract inner cell mass and now you have cultured pluripotent embryonic stem cells

95
Q

a pro erythroblast contains a large ___ but loses it completely when it differentiates into a mature RBC

A

nucleus

96
Q

bone marrow has capacity to become multiple tissues. true or false

A

true

97
Q

Mesenchymal stem cells and adipose tissue are in bone marrow. What do they differentiate into?

A

not blood like hematopoietic stem cells.

MSC can become other types of tissue

Molecular Biology (17 decks)

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