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4BBY1030 > SEMESTER 1 > Flashcards

SEMESTER 1 Flashcards

1
Q

who created the microscope

A

Robert hooke (1635-1703)

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2
Q

how many cells in the body

A

approx. 37 trillion cells

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3
Q

what are archaea

A

formerly archaebacteria
many species live in extreme environments

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4
Q

components of the cytoskeleton

A

actin filaments
intermediate filaments
microtubules

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5
Q

role of the cytoskeleton

A

maintain shape and stability.
adaptation of shape .
cell division.
motility.
movement of particles within cells.

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6
Q

how big is a mitochondrion

A

0.5-1um in diameter and 1-2 um in length

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7
Q

what is a lysosome

A

single membrane bound organelle that degrade unwanted proteins and particles taken up by the cell, and membranes and organelles that are no longer needed

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8
Q

pH of a lysosome

A

4.5-5

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9
Q

what are peroxisomes

A

degrade fatty acids and toxic compounds
involved in fatty acid oxidation, produces precursors for biosynthetic pathways. (H202)

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10
Q

what catalysed the earliest evolution of life (LUCA)

A

small reactive molecules,
minerals as catalysts,
high temperatures in hydrothermal vents,
RNA world, ribozymes,
DNA more stable,
lipid bilayers spontaneously form vesicles

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11
Q

why is bacteria reproduction error prone

A

it is fast

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12
Q

endosymbiotic theory

A

eukaryotic cell engulfs bacterium and becomes an organelle
(mitochondria, chloroplasts from photosynthetic bacteria)

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13
Q

evidence for endosymbiosis form chloroplasts

A

photosystem I - similar to photosystem in green sulphur bacteria and heliobacteria
photosystem II - similar to photosystem of purple and green filamentous bacteria

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14
Q

what are protozoans

A

single celled eukaryotes, motility, predation, not animals, plants, or fungi

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15
Q

who discovered cholera is caused by a rod-shaped bacterium (Vibrio cholerae)

A
  • Robert Koch (1884):
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16
Q

Who discovered penicillin

A
  • Alexander Fleming (1928): Nobel Prize for Medicine 1945
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17
Q

do archaea cause disease?

A

no, they live in extreme environments

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18
Q

properties of viruses

A

outside of host cell,
retroviruses, lentiviruses - integration events can be mutagenic,
dormancy,
very small,
pandoravirus (2,500 genes) can be seen under microscope.

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19
Q

function of actin

A

defines shape of cells and sub-cellular structures.
exerts force.
cell movement.
cell division.

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20
Q

what is the most abundant protein in eukaryotic cells

A

actin 15%-10%

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21
Q

how many amino acids does actin have

A

375 (small)

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22
Q

what an actin bind

A

ATP/ADP

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23
Q

what causes muscular dystrophy and haemolytic anaemias

A

actin mutations

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24
Q

how does actin form a fibre

A

-pointed end (minus)
-barbed end (plus)
growth of fibres is slower at minus end than plus end

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25
Q

what regulates microfilament dynamics

A

approx. 60 actin binding proteins

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26
Q

how does actin operate during cell division

A

contractile actin-myosin ring that squeezes cells apart

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27
Q

classes of intermediate filaments

A

cytoplasmic: keratins (epithelia), vimentin (connective tissue, muscle cells, and glial cells) and vimentin-related, neurofilaments (nerve cells)
nuclear: nuclear lamins (in all animal cells)

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28
Q

function of intermediate filaments

A

structure and support against stretch.
provide support against mechanical stress.

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29
Q

what causes epidermolysis bullosa

A

mutations in Keratin

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30
Q

function of nuclear lamins

A

provide stability to the nucleus

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31
Q

what do microtubules do in cell division

A

push chromosomes to the midline then pull them to the poles

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32
Q

what are microtubules composed of

A

dimers of alpha and beta tubulin

13 parallel protofilaments

polarity: beta tubulin = plus end, polymerises faster

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33
Q

where do microtubules originate

A

MTOCs (microtubule organising centres) such as the centrosome
significant % of cancers have abnormal centrosomes

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34
Q

how is microtubule stability regulated

A

microtubule associated proteins

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35
Q

what are motor proteins

A

fall into 2 category’s
kinesins: transport cargo from minus end to plus end (of microtubule)
dyneins: plus to minus

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36
Q

what is the role of myosin-I

A

transport vesicles/organelle along actin fibre.

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37
Q

what is the basement membrane/basal lamina

A

2D sheet on which epithelial cells reside

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38
Q

fibrillar matrix

A

3D matrix composed of various fibres, in which cells such as fibroblasts are buried

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39
Q

what are the two types of extracellular matrix

A

basement membrane and fibrillar matrix

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40
Q

where do you find basement membrane

A

epithelium, muscle, kidney glomerulus

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41
Q

main components of fibrillar matrix

A

colagen I
fibronectin
elastin
proteoglycans

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42
Q

what is an occluding junction

A

seals different compartments away from each other ~(tight junction)

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43
Q

what is a cell-cell anchoring junctions

A

junctions that anchor cells to each other adherens junctions and desmosomes

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44
Q

what are cell matrix anchoring junctions

A

junctions that anchor cells to extracellular matrix (focal adhesion and hemidesmosome)

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45
Q

what is the difference between adherens junction and desmosome

A

both are cell cell anchoring junctions but desmosomes anchor to intermediate filaments and adherens junctions anchor to the actin filaments

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46
Q

what is the difference between focal adhesion and hemidesmosome

A

both are cell-matrix anchoring junctions but the hemidemmosome anchors to then intermediate filaments and focal adhesion anchors to actin filaments in the cell.

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47
Q

what are channel forming junctions

A

form connection between the cytoplasm of adjacent cells (gap junctions).

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48
Q

what do tight junctions do

A

turn epithelia into barriers

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49
Q

where are adherent junctions found on epithelial cells

A

in close proximity of tight junctions

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50
Q

how do adherens junctions help conduct morphological changes of tissues

A

contracting junction complexes in groups of cells (important in embryonic development)

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51
Q

function of lamellipodium

A

drive cell movement

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52
Q

how do cells move along basement membrane

A

actin filaments attach to different focal adhesions and pull the rest of the cell behind them in a crawling motion

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53
Q

what are cadherins

A

calcium dependent adhesion molecules

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54
Q

what are selectins

A

adhere white blood cells in vessels (leukocyte rolling)

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55
Q

how is cell adhesion involved in metastasis

A

tumour cells use specific mechanisms to undermine the tight sealing of epithelium and move through the blood stream to a another location and form a secondary tumour (metastasis)

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56
Q

what is a nissil body

A

clusters of neuronal endoplasmic reticulum (within the cell body (soma))

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57
Q

what are the dendrites of a neurone

A

antenna for information

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58
Q

what is an axon hillock

A

meeting point between cell body and axon where the action potential is generated

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59
Q

what is the axolemma

A

axon membrane

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60
Q

what is the unidirectional flow of the neutron

A

AP always travels from dendrites to cell body to axon

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61
Q

why are our brains poor in regenerating

A

neurones are post mitotic so can’t divide and our brains have limited active stem cells

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62
Q

what is the make up of the neuronal cytoskeleton and what are their functions?

A

microtubule: transport
neurofilaments: structural
microfilaments: structural + movement

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63
Q

what is the minus end and plus end of a neurone

A

cell body is the minus end and nerve endings are the plus ends

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64
Q

dynein in axonal transport

A

move towards minus end (cell body)

move 50-250mm/day

transport mitochondria, endocytotic vesicles

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65
Q

kinesin in axonal transport

A

move towards plus end (pre synaptic nerve endings)

move 100-400mm/day

transport mitochondria, neurotransmitter vesicles

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66
Q

how are axons myelinated by glial cells

A

glial cell sits on axon and extends membrane and wraps the membrane around many times

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67
Q

what’s multiple sclerosis

A

auto-immune disease where neurones undergo de-myelination

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68
Q

what are the coverings for nerve fibres

A

endoneurium - surround axon

perineurium - surround groups of axons called fascicles

epineurium - surround groups of fascicles

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69
Q

what is nissl staining

A

stains cell body, ER

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70
Q

what is a multipolar neurone

A

send out dendrites from the cell body in many directions

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71
Q

what are glial cells

A

non neuronal cells that are part of the nervous system

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72
Q
A
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73
Q

what are the major classes of glial cells

A

CNS:
ependymal cells
oligodendrocytes
astrocytes
microglia
PNS:
satellite cells
Schwann cells

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74
Q

what are astrocytes

A

most abundant glial cells in brain tissue
provide structural support
regulate extracellular electrolyte homeostasis
energy storage

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75
Q

what do oligodendrocytes do

A

myelinate axons in the CNS (multiple at once)
inhibit axon regeneration in the CNS

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76
Q

what do microglia do

A

provide immune defence in the brain
induce a pro-inflammatory reaction
can be activated and become phagocytitic

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77
Q

what are ependymal cells

A

line the fluid filled spaces in the brain
secrete , monitor and aid in the circulation of cerebrospinal fluid
cilia and micro villi

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78
Q

what is choroid plexus epithelium

A

specialised epithelium in all ventricles; secretes cerebro-spino fluid

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79
Q

what are Schwann cells

A

myelinate pns axons
remove myelin debris by phagocytosis
promote axon regeneration

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80
Q

what are satellite cells

A

PNS glial cells that provide structural and metabolic support

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81
Q

what is extracellular recording of electrical potential

A

electrode outside cell (group of cells)

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82
Q

what is intracellular recording of electrical potential

A

electrode inside cell (one cell)

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83
Q

what is patch clamping

A

electrode sealed to cell surface (single cell)

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84
Q

what is the equilibrium potential of an ion

A

the membrane voltage required to prevent movement of an ion down its concentration gradient

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85
Q

how do you measure the amount of work done at the membrane

A

Nernst equation:
E= 58(mV) x log [c]out / [c]in

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86
Q

how do you calculate concentration gradient

A

[c]out/ [c]in for +ve ions
[c]in / [c]out for -ve ions

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87
Q

membrane potential difference for K and Na

A

E(k) = -90mV (if above K will leave)
E(Na) = +50mV (if below Na will enter)

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88
Q

what can move across the lipid bilayer

A

small uncharged or hydrophobic molecules can freely transverse by simple diffusion
charged polar molecules require specialist proteins

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89
Q

what is secondary active transport across a membrane

A

requires an electrochemical gradient
e.g Na+/Glucose transporter (intestine)

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90
Q

what is the octane/water
partition coefficient

A

(Kow) ratio of how soluble a solute is in water compared to octanol
higher = more lipid soluble

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91
Q

components of K+ channel

A

ion filter
gate

92
Q

example of mechanical gated channel

A

auditory receptors

93
Q

what is the Jmax in a rate of uptake against external membrane concentration graphs

A

max rate of uptake of molecule

94
Q

what is the Km in membrane transport

A

transporter affinity for substrate
lower Km higher affinity

95
Q

where does the brain get all its energy

A

sugar

96
Q

structure of GLUT1 glucose transporter

A

central cavity (aqueous cavity)
intracellular domains (latch)

97
Q

what is SGLT1

A

sodium glucose symporters
intestinal epithelial cells for the absorption of dietary glucose

98
Q

SGLT2: sodium-glucose symporters

A

sodium-glucose symporters
epithelial cells in proximal tubules of the kidney for reabsorption of glucose from the primary urine

99
Q

how would you treat cholera with Na+/ glucose cotransporter

A

replacement therapy includes a high concentration of glucose , which drives Na+ back into the intestine through the Na+/glucose symporter, SGLT1

100
Q

where does GLUT1 act

A

highly expressed in blood brain barrier, erythrocytes

101
Q

where does GLUT2 act

A

liver, kidney, intestinal epithelium, pancreatic beta cells

102
Q

where does GLUT 3 act

A

neurones

103
Q

where does GLUT4 act

A

muscle, adipocytes

104
Q

why are gap junctions important in neurones

A

smooth activation across cells

105
Q

what is the width of a synapse

A

0.5 um

106
Q

how are neurotransmitters removed from synapse

A

taken up by astrocytes and taken back up by presynaptic terminal
enzymes breakdown the molecule and taken into bloodstream or back to nerve

107
Q

inotropic receptor

A

allows ions in

108
Q

what is a graded potential

A

can be excitatory or inhibitory
gradual shift in charge following excitation
degrades over time and may not be strong enough to trigger AP along axon

109
Q

temporal summation

A

one graded potential after another
second one adds to the first and threshold is reached

110
Q

EPSP

A

excitatory postsynaptic potential

111
Q

IPSP

A

inhibitory postsynaptic potential

112
Q

metabotrapic receptors

A

combined to a G-protein

generates along-lasting more varied response

slower acting

113
Q

spatial summation

A

addition of multiple graded potentials at once

114
Q

somatic nervous system

A

motor fibres (general somatic efferens)
sensory fibres (general somatic afferens)

115
Q

visceral (autonomic) nervous system

A

sympathetic = fight or flight
parasympathetic = rest and digest
motor fibres (general visceral efferens)
sensory fibres (general visceral afferens)

116
Q

effect of parasympathetic nerves

A

constrict pupils
stimulate saliva
slow heart
constrict airways
stimulate activity of stomach
inhibit release of glucose; stimulate gallbladder
stimulate activity of intestines
contract bladder
project erection of genitals

117
Q

effects of sympathetic nerves

A

dilate pupils
inhibit salivation
increase heartbeat
relax airways
inhibit activity of stomach
stimulate release of glucose; inhibit gall bladder
inhibit activity of intestines
secrete epinephrine and noradrenaline
relax bladder
promote ejaculation and vaginal contraction

118
Q

anatomical directions

A

ventral forward (belly side)
dorsal back (back)
(rostral) anterior up (head)
(caudal) posterior down (feet)

119
Q

planes of section

A

horizontal (flat)
coronal (crown)
sagital (middle part)

120
Q

names for surfaces of the cerebrum

A

gyrus = ridges
sulcus = grooves
fissures = deep grooves

121
Q

major subdivisions of the brain

A

forebrain
midbrain
hindbrain (pons, cerebellum, medulla)
spinal chord

122
Q

4 lobes of brain

A

frontal lobe
parietal lobe
occipital lobe (vision)
temporal lobe (memory language)

123
Q

how many pairs of spinal nerves

A

31

124
Q

why is spinal chord shorter than vertebral column

A

spinal nerves hang down and leave at an angle
harder to damage

125
Q

why is brain fluid filled

A

make brain less heavy
cushions entire brain
remove waste product
contains growth factors

126
Q

how much cerebrospinal fluid do we produce each day

A

500ml normally reabsorbed into blood stream
if this pathway blocked = hydrocephalus

127
Q

meningeal layers of CNS (protective)

A

pia mater (inner) tightly adhered
arachnoid mater (intermediate)
dura mater (outer)
CSF released between layers 1&2 the sub arachnoid space

128
Q

how is cerebrospinal fluid recycled into the blood

A

via arachnoid granulations into venous blood

129
Q

purpose of the cell cycle

A

copy genome and partition the copies equally between the daughter cells
enable a multicellular organism to grow to adult size
maintain total cell number of an adult organism
replace lost or damaged cells

130
Q

prokaryote cell division

A

binary fission
DNA attached to cytoplasmic membrane (nucleoid)
cell enlarges and DNA duplicates
septum forms
cell divides in two

131
Q
A
131
Q

replication of DNA in prokaryotes

A
  • circular chromosome has one origin of replication
    -two replication forks form at the origin (bidirectional replication
    -two identical copies of the circular chromosome
132
Q

cytokinesis of prokaryote

A

-FtsZ distributed within cell
-FtsZ ring forms and contracts
-cell spits

133
Q

how is the DNA replication speed brought up to the cytokinesis speed

A

-multiform replication
-replication of DNA initiated before completion of previous round

134
Q

what is G1

A

growth phase, doubling the mass of organelles and protein, including synthesis of enzymes that will drive DNA replication

135
Q

what is S phase

A

DNA synthesis phase. chromosome duplification

136
Q

during the cell cycle how is premature chromosome separation prevented

A

after replication, sister chromatids are held together by cohesin

137
Q

what is cohesin made up of

A

SMC3 and SMC1 and kleisin

138
Q

what is G2

A

preparation for mitosis. the beginning of mitosis is marked by two events:
-chromosome condensation
-formation of mitotic spindle

139
Q

what drives condensation of the chromosomes

A

condensin

140
Q

how does condensin condense chromosomes

A

condensin encircles loops of DNA and compresses the sister chromatids to give a compact structure

141
Q

what does the mitotic spindle bind to

A

kinetochore
-complex of proteins attached to the centromere

142
Q

how is cohesin removed from sister chromatids

A

kleisin subunit of cohesin is cleaved by a protease

143
Q

how do mitotic spindle have access to the chromosomes

A

during G2 the nuclear membrane breaks down and mitotic spindle can enter

144
Q

what is the phragmoplast

A

guides synthesis of new cell wall in plant cell division
contains microtubules derived from the mitotic spindle

145
Q

when is the cell cycle the shortest and why

A

early embryonic stages
division without growth

146
Q

cell cycle time in liver

A

1 year

147
Q

why do unicellular organism carry out closed mitosis

A

nuclear envelope remains intact throughout
spindle pole body is imbedded within the membrane

148
Q

during mitosis what is distributed symetrically and symmetrically

A

DNA distributed symmetrically
cell fate determinants distributed asymmetrically

149
Q

polarity in stem cell division

A

one cell is attached to niche cell and fated to retain its identity as a stem cell
and another cell is free to dissociate

150
Q

what is contact inhibition

A

once cells contact each other they stop growing. inactivated in cancer cells

151
Q

what does cyclin dependent kinase do

A

drive the phases of the cell cycle. it is the activity (not the levels) of the kinase that activate the phases of the cycle

152
Q

what controls the activity of kinases

A

cyclin.

undergo cycles of synthesis and degradation so levels rise and fall

different CDKs and cyclins activate different phases

153
Q

which cyclin activates G1/S CDK

A

cyclin E

154
Q

what phase of cell cycle does G1/S CDK drive?

A

transition from G1 to S phase.

commits cell to the cycle

155
Q

what cyclin does MCDK bind

A

cyclin B

156
Q

what does M CDK do in the cell cycle?

A

promotes entry into mitosis.

activates condensin

induces nuclear membrane breakdown

157
Q

how is the activity of M CDK diminished after mitosis

A

cyclin B degradation

158
Q

G1 checkpoint

A

R (restriction point)
positive signal from the outside will instruct the cell to divide

159
Q

G2/M checkpoint

A

is dna synthesis complete?
cell cycle is suspended if not

160
Q

M checkpoint

A

is each chromosome attached to spindle?

161
Q

what are anuploidies and trisomies

A

A: chromosome numbers other than 46
T: 3 copies of a chromosome

162
Q

4 main types of intercellular communication

A

endocrine
paracrine
neuronal
contact dependent

163
Q

what is autocrine signalling

A

special type of paracrine signalling where the secreting cell contains receptors for the secretory molecule

164
Q

examples of signalling faces in cell signalling

A

hormones
growth factors
metabolic regulators
neurotransmitters
migratory cues
cell death factors
developmental patterning factors

165
Q

intracellular receptors

A

either in the cytoplasm or in the nucleus

166
Q

major membrane receptor families

A

ion channels
G-protein couples receptors
enzymes

167
Q

G-protein couples receptors (GPCRs) structure

A

7 transmembrane domains
amino terminus in the exterior
carboxy terminus in the cytosol

168
Q

functionality of GPCR

A

G protein is heterotrimeric which means it has 3 different subunits (alpha, beta and gamma)
A subunit is bound to GTP at rest, when signal binds GDP exchanges for GTP

G(alpha)-GTP activates effector enzyme adenyl cyclase which produces second messenger (cAMP)

169
Q

what does cAMP do

A

activates protein kinase A PKA

170
Q

what does protein kinase A do

A

phosphorylate proteins to make them functional active
has 2 subunits (regulatory and catalytic)
catalytic group phosphorylates proteins
atp phosphate donor
serine threonine kinase

171
Q

what is a protein phosphatase

A

remove phosphate group from a protein and makes it inactive

172
Q

what is protein kinase C

A

activated by adrenaline
(alpha 1 adrenergic receptor)
activated by ca ions and diacylglycerol

173
Q

how is adrenaline able do have different effects

A

different receptors types for same ligand

174
Q

effect of adrenaline on beta GPCR

A

2nd messenger:cAMP
causes glucose metabolism

175
Q

effect of adrenaline on alpha 1 GPCR

A

2nd messenger DAG, IP3, Ca2+
causes contraction of smooth muscle

176
Q

what is endocytosis

A

uptake of outside material(fluids and macromolecules) by invagination of the plasma membrane followed by pinching off and intracellular vesicle formation

177
Q

mechanism of phagocytosis

A

-receptors that bind bacteria activated
-activation of F-actin polymerisation
-membrane protrudes and zippers around particle and phagosome sealed off
-F-actin disassembles
-fuses with lysosomes = phagolysosomes
degradation of content

178
Q

function of macropinocytosis

A

uptake of fluid for feeding and removal of large number of growth factor receptors from plasma membrane

179
Q

types of endocytosis

A

Cathrin mediated:
dynamin dependent - constitutive receptor-mediated, ligand induced receptor mediated
non-clathrin mediated:
dynamin-dependent- cave-in-mediated
dynamin-independent

180
Q

Clathrin-mediated endocytosis function

A

receptor-mediated endocytosis allows the cell to take up specific macromolecules which are not abundant in the extracellular fluid via more than 25 different receptors

181
Q

Cathrin mediated endocytosis: mechanism

A

egf receptor bings egf
adoption binds the inside of the receptor
bud formation
dynamin pinches off the vesicle (actin can contribute)
uncoating

182
Q

what is dynamin

A

large protein that oligomerise into spirals
required for fission of vesicles

183
Q

what is the functional unit of Cathrin

A

tryschelium

184
Q

what mediates Cathrin cade disassembly

A

HSC70
auxilin

185
Q

cytoplasmic pathway of a protein

A

-ribosome
-protein completed and released in folded form into cytoplasm (nucleus, peroxisome,cytoplasmic protein)
un folded protein transported to mitochondria where it is folded

186
Q

where do endoplasmic reticulum pathway proteins get transported to

A

lysosomes, peroxisomes,new cytoplasmic membrane
secretory vesicles

187
Q

what determines the pathway of proteins

A

endoplasmic reticulum signal sequence

188
Q

what binds ER signal sequence to ER membrane

A

signal recognition particle SRP

189
Q

destinations of ER pathway

A

-ER lumen
-further vesicular compartments
-secreted from cell
-embedded in membrane

190
Q

what docks transport vesicle to plasma membrane

A

v-snare on vesicle and t-snare on target (membrane)

191
Q

what are glycosyltranferases

A

enzymes in Golgi that add sugars to proteins

192
Q

what three alleles of glycosyltransferases glycosylate the proteins on red blood cells

A

O, A, B

193
Q

necrosis

A

traumatic cell death from acute injury

194
Q

apoptosis

A

activation of a death programme

195
Q

what causes apoptosis

A

-withdrawal of growth factors
-chemotherapy
-contact with cytotoxic T cells
-following a developmental programme

196
Q

characteristics of necrosis

A

-membrane damage
-chromatin flocculation
-energy levels rapidly depleted
-leaking of cellular contents
-elicits an inflammatory response

197
Q

apoptosis pathway

A

-chromatin condensation and membrane blebbing

-cell fragmentation (into apoptotic bodies)

-apoptopic bodies engulfed by phagocytes

198
Q

why do apoptoses?

A

-during metamorphosis
-elimination of cells that have served their purpose
-cells infected by viruses
-cancer cells
-cells bearing excessive DNA damage
-promote self tolerance. auto reactive lymphocytes undergo apoptosis before they fully develop

199
Q

where is DNA cut during apoptosis

A

DNA cleaved in linker regions between nucleosomes

200
Q

how do we detect new free ends of DNA after apoptosis

A

TUNNEL assay

201
Q

how does annexin V detect apoptosis cells

A

phosphotidile serine in plasma membrane flips and can be detected

202
Q

why do phosphotidile serene lipids expose the the surface during apoptosis

A

this is a signal for phagocytes to bind and engulf the cell

203
Q

what enzymes drive apoptosis in eukaryotes

A

capsases

204
Q

what do caspases target

A

lamins
gelsolin (regulator of actin filament assembly/disassembly)

205
Q

example of excess apoptosis

A

-heart attack
-type I diabetes Miletus

206
Q

excitotoxicity

A

if excess glutamate is transported to a neurone it can cause unwanted cell death

207
Q

how germ cells form in development

A

-primordial germ cells first seen in proximal epiblast pre-gastrulation.
-migrate to posterior during gastrulation
-migrate to gonads
-differentiate into egg or sperm

208
Q

how meiosis ensures the gametes have the correct amount of genetic material

A

two cell divisions with DNA replication only taking place before the first division

209
Q

how fertilisation occurs in mammals

A

-fusion between sperm and egg in the fallopian tube
-divides and forms a blastocyst which is then implanted into uterine wall
-sperm binds and penetrates zona pellucida
- plasma membrane of sperm fuses with egg plasma membrane

210
Q

describe asexual reproduction in hydra

A

-little region buddy of the side of the embryo
-buds off and becomes its own organism

211
Q

what is parthenogenesis

A

development of an embryo from an unfertilised egg cell
(haploid diploid bees)

212
Q

cortical granule exocytosis

A

due to high Ca2+ granule membrane fuses with egg membrane
contents of granules released into space between cell membrane and vitelline envelope.
enzymes from cortical granules harden

213
Q

innate immunity

A

non specific, rapid, response to infections, response to altered self

214
Q

adaptive immunity

A

-specific
-slower to develop
-response to infections
-response to altered self
-can be humoural or cell mediated
-has memory

215
Q

B vs T cells

A

Both arise from bone marrow and activated in secondary lymphoid organs and have a capacity to produce memory cells
B - mature in bone marrow, secrete antibodies
T - mature in thymus, induce a cell mediated response

216
Q

antigen presenting cells

A

e.g dendritic cells

217
Q

secondary lymphoid tissues

A

sites where immune responses are carried out

218
Q

mesenchymal cells

A

connective tissue, bone, cartilage, fat

219
Q
A
220
Q

2 things stem cells must be able to do

A

self renew and differentiate

221
Q

ensuring cultured cells are embryonic stem cells

A

-karyotyping
-expression of pluripotent markers
-differentiate
-transplant

222
Q

reproductive cloning

A

enucleated egg + nucleus from somatic cell = egg with transplanted nucleus which develops into a clone of the nucleus donor

223
Q

what are yamanaka factors

A

OCT4
SOX2
KLF4
C-MYC
The original set of reprogramming factors

224
Q

antigen recognition

A

immunoglobin (secreted antibody and BCR) recognise whole antigen
TCR recognises processed antigen fragments presented by MHC

225
Q

antibody segments

A

variable regions of the antibody are made up of two or three gene segments - VJ (kappa or lambda light chain) or VDJ (heavy chain)

226
Q
A

4BBY1030 (1 decks)

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