B2.3 Cell Specialisation Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

what is a stem cell

A

cell that can divide (by mitosis) an unlimited number of times

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

what tissues retain stem cells

A

bone marrow(for rbcs, wbs, platelets)
hair follicle

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

what is the potency

A

The ability of stem cells to differentiate into more specialised cell types

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

totipotent

A

can differentiate into any type of cell found in an embryo and extra embryonic cells eg. zygote

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

example of how active white blood cells are differentiated for function

A

larger than inactive white blood cells to allow space for rER and Golgi apparatus to allow protein (antibody) synthesis

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

as the size of an organism increases, what happens to its surface area to volume ratio

A

decreases
more difficult for an organism to gain enough oxygen and nutrients at its cell surface, as its requirements will increase faster than the available surface for diffusion

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

investigated sa with agar method

A

cut coloured agar into cubes of required dimensions
calc sa, vol, and sa to v ratio of each cube
place cubes into boiling tubes containing diffusion solution
measure time taken for agar cubes to become colourless

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

how are red blood cells specialised

A

function- carry oxygen from lungs to respiring cells
they are FLATTENED and have a BICONCAVE shape to maximise surface area and minimise volume so oxygen can diffuse into it quickly in lungs and out

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

what are proximal convoluted tubules

A

tiny tubes found in the outer region of the kidney which are responsible for the reabsorption of vital substances like glucose and mineral ions

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

how do cells of proximal convoluted tubule increase surface area

A

have microvilli and invaginations

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

what are type 1 pneumocytes

A

extremely thin alveolar cells which make up the majority of the alveolar epithelium

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

how are type 1 pneumocytes adapted

A

provide a short diffusion distance to maximise the rate of gas exchange
capillary walls are also only one cell thick maximises the rate of diffusion

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

what are type 2 pneumocytes

A

rounded cells that have many secretory vesicles which secrete a solution that coats the epithelium of the alveoli

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

what is the solution released by type II pneumocytes

A

pulmonary surfactant has hydrophobic tails and hydrophilic heads
which form a monolayer

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

benefits of pulmonary surfactant

A

reduces surface tension, maintaining alveolar shape and preventing the alveoli sacs sticking together
provides moisture so oxygen can dissolve before it diffuses into the blood
Carbon dioxide diffuses from the moist surface before it is removed in exhalation

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

are skeletal muscles striated

A

yes

17
Q

what are striated muscles bundled into

A

into fibres which are surrounded by a single plasma membrane called the sarcolemma

18
Q

what does each muscle fibre contain

A

an organised arrangement of CONTRACTILE PROTEINS in cytoplasm
many nuclei
sarcoplasmic reticulum
mitochondria and myofibrils

19
Q

what are myofibrils

A

bundles of actin and myosin filaments, which slide past each other during muscle contraction

20
Q

what doe the sarcolemma have

A

many deep tube-like projections that fold in from its outer surface- T tubules they run close to SR

21
Q

is a cardiac muscle a striated

A

yes

22
Q

how are cardiac muscle fibres connected to each other

A

via specialised branched connections called intercalated discs, which allows the contraction to spread more quickly across the chambers of the heart

23
Q

how are sperm cells specialised

A

has a haploid nucleus in streamlined head- fuse w ovum to form diploid zygote
acrosome w digestive enzymes to enter ovum
many mitochondria for movement
a flagellum for movement

23
Q

why are there lots of mitochondria in muscle fibres

A

to provide the large quantity of ATP needed for continual contraction

24
Q

how are egg cells specialised

A

Follicle cells which nourish and protect the ova
have haploid nucleus
A cytoplasm rich in nutrients for the developing embryo after fertilisation
vesicles with digestive enzymes to prevent polyspermy