all7. Flashcards

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

Function of cholesterol

A

stabilise the membrane OR maintain / affect / control / AW,

fluidity OR reduces permeability to, polar / charged, particles

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

Function of protein / glycoprotein / intrinsic protein / protein channel /
protein pump / transport protein / carrier protein

A

allow communication across membrane OR allow, polar /

charged, particles to pass through membrane

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

Function of phospholipid (bilayer) / phospholipid head

A

to act as a barrier (to, polar / charged, particles) / select
what enters or leaves cell

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

Definition: cell signalling

A

communication between cells
cell, recognition / identification;
cells work together / coordination between action of different cells;
to trigger, response / reaction ( inside the cell

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

how a glycoprotein can act as a receptor

A

(receptor) specific shape / described;
complementary to (shape of), trigger / named trigger /
communicating;
molecule;
(trigger / AW) binds / attaches to receptor

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

why there was no transmission of light after the beetroot had been placed in water at 100 °C

A

cell surface / plasma, membrane damaged;
pigment, released / leaks out;
pigment, absorbs / takes up, the light;

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

The loss of water from the aerial parts of a plant is known as…

A

transpiration

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

Water is transported up the stem in

The…

A

xylem

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

From the air spaces in the leaf, the water vapour diffuses out of the leaf through
The….

A

stoma(ta) / stomatal pore

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

Explain why water loss from the leaves of a plant is unavoidable

A

stomata (open to) allow, gaseous exchange / carbon dioxide in /
oxygen out / AW;
(gaseous exchange) for photosynthesis;
(photosynthesis) essential for plant to, gain energy / make sugars;
some water lost through cuticle

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

the type of plant adapted to reduce water loss from its leaves

A

xerophyte

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

State and explain two adaptations of leaves that reduce evaporation

A

A 1] hairy leaves;
trap water vapour / moisture;
[A 2] stomata, in pits / sunken;
pits trap, water vapour / moisture;
[A 3] rolled leaves / presence of hinge cells;
reduce surface area OR (rolled leaves) trap water vapour /
moisture;
[A 4] high solute concentration in cells;
reduces water potential inside leaf cells;
[A 5] thick(er) cuticle;
(which is) waterproof / (relatively) impermeable;

[A 6] small leaves / needles; smaller surface area;
[A 7] fewer stomata; reduces diffusion (of water vapour);
[A 8] stomata close, during the day; reduces diffusion (of water vapour);
[A 9] most stomata on lower surface; less exposure to sun OR cooler OR reduces diffusion (of water vapour); A 10] more densely packed spongy mesophyll; smaller surface area for evaporation (from mesophyll cell surface); key words: cuticle, impermeable, water vapour, potential gradient, diffuse / diffusion, stoma(ta), needles, surface area, hinge cells, saturated
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Structure of prokaryotic cells

A
no true nucleus
genetic material consists of ‘naked’ DNA
average diameter of cell 0.5 – 5 µm
(ribosomes) 18nm;
cell wall (present);
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Structure of eukaryotic cells

A
genetic material held in a nucleus
as chromosomes / chromatin
OR
(genetic material) associated
with, proteins / histones;
(diameter of cell) 20 – 40 µm;
ribosomes about 22 nm in diameter
cell wall sometimes present
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

structure, associated with the cytoskeleton, which can bring about cell movement

A

flagellum / cilium / microtubule / microfilament / undulipodium

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

processes inside cells that rely on the cytoskeleton for movement

A
(movement inside cells of)
	chromosomes / chromatids (in cell division);
(cytoplasm in) cytokinesis;
organelles / named organelle;
	RNA (in protein synthesis);
proteins;
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

During stage S, the genetic information is copied and checked.
Suggest what might happen if the genetic information is not checked

A

mutation / faulty DNA produced / error in copying;
daughter cells will not receive identical genetic information;
proteins / (daughter) cells, not made / do not function

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

During meiosis a cell undergoes two divisions.

Suggest how cells produced by meiosis may differ from those produced by mitosis

A

haploid / half genetic information / chromosome number is n;
genetic information not identical / produces genetically different
cells;
4 cells produced;

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

the type of muscle found in the walls of the heart chambers

A

cardiac

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

the process that creates pressure inside the heart chambers

A

muscle) contraction / systole

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

Golgi apparatus function

A

repackage / transport, proteins;

add carbohydrate group to protein

22
Q

Ribosome function

A

site of protein synthesis

23
Q

how the structure of the sperm cell is specialised for carrying out its role

A

flagellum for movement;
chromosomes / DNA, in haploid nucleus / AW, for fertilising egg cell;
head / cap / acrosome, shaped for penetrating egg cell (membrane);
(many) mitochondria for energy / ATP, for movement

24
Q

Definition: tissue

A

group of cells;
of one or more types; A ‘common origin’
with intercellular material/connective tissue / AW;
(specialised) to perform particular function(s);

25
Q

Example of a plant tissue

A

xylem / phloem / epidermis / mesophyll / palisade / spongy mesophyll /
chlorenchyma / etc./ meristem / cambium / suitable named tissue

26
Q

the approximate width of the membrane

A

7nm;

27
Q

Structure of phospholipid

A

hydrophilic / polar/AW, head;

hydrophobic / non-polar / AW tail

28
Q

Function of channel protein

A

allow, small / charged, molecules through membrane

29
Q

roles of glycoproteins in membranes

A

stabilises membrane structure by forming hydrogen bonds with water
molecules;
antigens for cell recognition;
binding sites, for, chemicals/ drugs / hormones / neurotransmitters/
antibodies /T cells;
receptors for cell signalling / triggers chemical reactions inside cell;

30
Q

Glycoprotein structure

A

a protein embedded in the membrane with a branched carbohydrate chain projecting out from the surface of the cell

31
Q

Why single-celled organisms generally have a larger surface-area to volume ratio

A

living cells need to take in oxygen/ nutrients and remove (metabolic)
waste;
ref. passive processes / diffusion;
rate of diffusion too slow if SA:V ratio too small;

32
Q

The lungs in the mammalian body are well developed to allow effective exchange of gases.
Describe the features of the lungs that make them effective organs for the exchange of gases

A

many alveoli to produce large surface area;
barrier, thin / only two cells thick;
good blood supply / many capillaries;
to carry dissolved gases to and from the alveoli;
ventilation / air movement to refresh the air in the alveoli;
(contains) elastic tissue to stretch and recoil to help expel air;

33
Q

why the volume of air in the spirometer drops slowly over the first minute

A

oxygen is used in respiration;
carbon dioxide is released ( in respiration);
carbon dioxide is absorbed (by soda lime);

34
Q

Definition: double circulatory system

A

blood flows) twice through the heart / AW;
for one circuit / cycle (of the whole body) / AW; A for one heart beat
ref pulmonary and systemic systems / to lungs and to (rest of) body;

35
Q

why the wall of chamber the left ventricle is much thicker than the walls of chambers of the right atrium and the right ventricle

A

provides more, force / pressure, to pump blood around body;
longer distance compared with distance right ventricle has to pump blood;
or right atrium

36
Q

Haemoglobin, a pigment found in the blood of mammals, has an important role in the…

A

transport of respiratory gases

37
Q

Each haemoglobin molecule contains…

A

Haem groups

38
Q

In the lungs, oxygen binds with the atom of… in each haem group

A

iron

39
Q

The maximum number of molecules of oxygen that can be carried by one molecule of haemoglobin is…

A

4

40
Q

In areas like muscle tissue where the partial pressure of oxygen is low…

A

oxygen dissociates from the haem group

41
Q

This dissociation is increased by the presence of carbon dioxide; this is called the…

A

Bohr, effect / shift

42
Q

Most of the carbon dioxide produced in respiring tissues diffuses into the red blood cells where the enzyme…. catalyses a reaction leading to the production of hydrogen ions and hydrogen carbonate
ions

A

carbonic anhydrase

43
Q

. The hydrogen ions combine very readily with haemoglobin to form a compound
known as…. The effect of this is to increase
the release of oxygen from haemoglobin.

A

haemoglobinic acid

44
Q

Transpiration itself is not measured directly by a potometer.
State what is measured by this apparatus

A

water uptake

45
Q

Describe how the potometer should be set up to ensure that valid measurements can be made

A

1 cut (healthy) shoot under water (to stop air entering xylem vessels);
2 cut shoot at a slant (to increase surface area);
3 check apparatus is full of water / is air bubble free / no air locks;
4 insert shoot into apparatus under water / AW;
5 remove potometer from water and ensure, airtight / watertight,
joints around shoot;
6 dry leaves / AW; max 4
7 keep, condition(s) / named condition(s), constant;
8 allow time for shoot to acclimatise / AW;
9 shut screw clip;
10 keep ruler fixed and record position of air bubble on scale;
R ‘move bubble to end’ ideas
11 start timing and, measure / calculate, distance moved per unit time

46
Q

In coastal regions, unusually high tides can cause flooding of land that is not normally covered by sea water.
Explain how plants living in these regions would be affected by the change in water potential (Ψ) of the soil caused by such flooding.

A

1 (water moves) by osmosis;
2 down water potential gradient/from high Ψ to low Ψ;
(less negative to more negative)
3 sea water has low water potential/(soil) water potential decreased;
(more negative)
4 Ψ, gradient reduced/lower than inside, root/cells/plant;
5 plant, loses/can’t absorb (as much), water;
6 cells, flaccid/lose turgor;
7 plasmolysis/described;
8 wilting/poor growth; in correct context

47
Q

Outline the roles of membranes at the surface of cells and within cells.

A

at surface
S1 separate cell from environment;
S2 control, entry/exit (of molecules/ions/suitable substance);
A selective/partial R semi-permeable
S3 use of phospholipid layer (in allowing or preventing passage) of
suitable example;

S4 reference to facilitated diffusion;
S5 reference to active uptake; R channel protein
S6 reference phagocytosis/pinocytosis/endocytosis/exocytosis;
S7 cell recognition/cell surface antigens;
S8 cell to cell attachment;
S9 receptor (for hormones/neurotransmitters etc.);
S10 AVP; microvilli increase surface area of cell
enzyme attachment
further role max 6

within W1	compartmentalise/surrounds organelles; W2	prevents disruption of, reactions/process; A reaction more efficient W3	e.g. reaction/process, and organelle; W4	reactions take place on membranes; A named example of membrane W5	enzymes attached to membranes; A named example W6	isolates/separates, DNA/nucleus;

W7 (nuclear pore) permits RNA to leave nucleus;
W8 (forms) ER/(Golgi) vesicles/lysosomes/other named organelle;
(not the same e.g. as W3 or W6)
W9 attachment of ribosomes;
W10 intracellular transport;

W11 protects cells from contents of lysosomes;
W12 (tonoplast) surrounds/controls content of, vacuole;
W13 AVP; increases (internal) surface area of organelle
attachment of pigments
formation of mesosomes

48
Q

why liver cells of the type shown in the diagram contain many mitochondria

A

(liver requires) a lot of, energy/ATP

49
Q

The haploid number of chromosomes for a human is 23.

(i) State the number of chromosomes present in the nucleus of the liver cell

A

46/23 pairs

50
Q

the type of nuclear division that produced this liver cell

A

mitosis