Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology > IGCSE Biology > Flashcards

IGCSE Biology Flashcards

1
Q

Define movement

A

action by organism/part of organism causing change in position/place

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

Define respiration (2)

A

chemical reactions in cells

break down nutrient molecules and release energy for metabolism

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

Define sensitivity

A

ability to detect stimuli in internal/external and respond appropriately

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

Define growth

A

permanent increase in size/dry mass by increase in cell number/cell size (both)

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

Define excretion

A

removal of waste products from organisms

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

Define nutrition (2)

A

raw materials needed to release energy

to make more cells for growth/development/repair

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

Function of cell membrane (2)

A

holds cell together

controls substances entering/exiting cell

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

Function of cytoplasm

A

suspends organelles

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

Function of nucleus (2)

A

control cell activities/division

stores genetic material

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

Function of cell wall (2)

A

supports cell

defines cell shape

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

Function of vacuole (3)

A

storage of some materials

support cell shape

contains cell sap - prevents plant from wilting

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

Function of chloroplasts

A

photosynthesis

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

Features of red blood cells (3)

A

no nucleus - to make more space for haemoglobin

biconcave shape - for faster diffusion

haemoglobin - reacts with oxygen

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

Define acrosome (2)

A

tip of sperm cells

contains enzymes - break down egg cell membrane

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

Define flagellum

A

tail of sperm cell which powers movement

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

Function of cytoplasm in egg cell

A

energy storage - nutrition for fertilised cell

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

Function of jelly coat of egg cell (2)

A

protects cell

hardens + prevents other sperm cell from entering once one sperm enters

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

Function of root hair cells

A

absorb water/minerals

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

Magnification formula

A

image size/actual size

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

Define diffusion

A

net movement of particles from area of high concentration to an area of low concentration down a concentration gradient and through a partially permeable membrane

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

Define active transport

A

net movement of particles from area of low concentration to area of high concentration against concentration gradient using energy

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

Define a turgid plant cell

A

plant cell full of water

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

Define turgor pressure

A

pressure of water in cytoplasm pushing against cell wall

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

Define osmosis

A

movement of water particles from one area of high water potential to an area of low water potential down a water potential gradient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Define water potential

A

ability of a cell to draw water into itself

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Define a plasmolysed/flaccid cell (3)

A

dehydrated plant cell

cytoplasm shrinks

cell membrane pulls away from cell wall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Ciliated Epithelial Cell (3)

A

located in lining of respiratory tract

move liquid called mucus - particles of dust + bacteria trapped in mucus

mucus emptied into esophagus then into stomach

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Adaptations of sperm cells

A

many mitchondria - provides energy for movement of flagellum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Root hair cell adaptations

A

elongated shape - increases surface area for absorption of water + dissolved mineral ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Define carbohydrates (2)

A

made up of simple sugars

formed from carbon, hydrogen,oxygen atoms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Define protein (2)

A

long chains of amino acids

formed from carbon,hydrogen, oxygen, nitrogen, (sulfur)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Define lipids (2)

A

made from fatty acids and glycerol

formed from carbon,hydrogen, oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Test for starch (3)

A

iodine solution

positive - blue/black

negative - brown

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Test for glucose/reducing sugars (6)

A

benedict’s solution

positive - orange-red

medium - yellow

small amount - green

negative - blue

must heat benedict reagent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Test for protein (3)

A

biuret’s reagent

positive - purple

negative - blue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Test for lipids (3)

A

ethanol

positive - emulsion, cloudy white solution

negative - clear

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Function of biological catalyst

A

speed up rate of reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Define a substrate

A

molecule enzyme binds to at start of reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Define a product

A

molecule formed at end of reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Define complementary

A

enzyme active site shape matches substrate shape

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Define an enzyme’s active site

A

space where substrate fits into enzyme

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Define an enzyme substrate complex

A

substrate binding to enzyme

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Enzymes are specific and unique

True or false

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Effect of temperature on enzyme activity (4)

A

temperature increase = more kinetic energy = increase in collisions

greatest at optimum temp

greater than optimum temp = denaturation

rate of reaction decrease as enzyme active site no longer complementary to substrate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Effect of pH on enzyme activity (2)

A

optimum pH = rate of enzyme reaction highest

low/high pH = denaturation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Effect of substrate concentration on enzyme activity (3)

A

substrates increase = faster rate

gradient decreases as less active sites available

gradient plateaus = all active sites occupied

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Define photosynthesis

A

process which plants manufacture carbohydrates from raw materials using energy from light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Are plants autotrophs

A

yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Define autotrophs

A

organisms that are able to make their own food

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Purpose of chlorophyll (2)

A

transfers light energy into chemical energy in molecules

used for synthesis (production) of carbohydrates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Word equation of photosynthesis

A

carbon dioxide + water –> glucose + oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Balanced chemical equation of photosynthesis

A

6CO2 + 6H2O –> C6H12O6 + 6O2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

Name layers of the structure of a leaf in order (7)

A

waxy cuticle

upper epidermis

palisade mesophyll

Spongy mesophyll

Lower epidermis

Guard cells

waxy cuticle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

Features of palisade mesophyll cells (4)

A

where most photosynthesis occurs

contains many chloroplasts

columnar shape allows many cells to be tightly packed to maximise absorption

found close to upper surface of leaf

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

Stomata and guard cells function (3)

A

play role in gas exchange

gases enter and exit through stomata

guard cells open or close in response to environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

Function of xylem

A

transports water and minerals from root to leaves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

Function of phloem

A

transports sugars (sucrose) and amino acids from leaves to other parts of plant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

By which process is glucose produced

A

photosynthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

What is glucose used for (5)

A

energy

growth of shoots

growth of young leaves

growth of fruit

root growth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

Purpose of sucrose (2)

A

converted from glucose

less reactive than glucose so not lost if transported

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

Where is sucrose transported

A

phloem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

Purpose of starch

A

storage of glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

Function of nitrate ions

A

synthesis (production) of amino acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

Function of magnesium ions

A

chlorophyll production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

Deficiency of magnesium and nitrate ions (2)

A

stunted growth

yellow leaves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

What chemical is used to test for starch

A

iodine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

Experiment layout for testing starch availability in plants (7)

A

remove leaf from plant

place in beaker of boiling water for 30 seconds to break open cells

place in boiling tube of ethanol inside the beaker of boiling water - removes chlorophyll from leaves

remove leaf after 1 minute using forceps

rinse leaf with cold water

spread leaf on white tile and drip iodine on it

positive result is blue/black

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

Define variegated leaves

A

leaves which have green and white parts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

Answering 7 mark experiment question (8)

A

independent variable

dependent variables

control variable (2)

safety precautions

how you will set up the experiment

how and how often you record data

how you will analyse results

what results show

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

Determinants for the rate of photosynthesis (3)

A

light intensity

CO2 amount

temperature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

Define limiting factor

A

factor at lowest level which limits rate of reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

Purpose of water in plants (2)

A

needed for photosynthesis

maintain turgor pressure and keep structure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

How is water absorbed into roots (3)

A

osmosis

high concentration of minerals in root cells

water drawn into cells from high water potential (soil) to low water potential (cells)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

Adaptation of root cells

A

root hair cells increase surface area for osmosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

Transport of water in plant (3)

A

once inside root cells water passes through xylem vessels up stem into leaves

if leaf photosynthesizing, water lost through open stomata

process called transpiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

Define transpiration (3)

A

loss of water from a plant by evaporation at surface of mesophyll cells

also diffuses out as water vapour through stomata

draws more water and minerals through xylem and up roots

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

Define transpiration stream

A

flow of water through plant taking water up roots

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

Pathway of water through roots, stem and leaf (4)

A

root hair cells

root cortex cells

xylem

mesophyll cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

Purpose of lignin in xylem vessels

A

supports structure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

How does water move upwards in the xylem (7)

A

transpiration pull made by water potential gradient between roots and leaves

water evaporates at surface of mesophyll cells

water vapour diffuses through stomata

creates water potential gradient

causes lower water potential compared to higher water potential in roots

water absorbed by root hair cells

water moves up xylem as unbroken column of water molecules - held together by cohesion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

4 main factors which affect rate of transpiration (4)

A

Light intensity

Temperature

wind speed

humidity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q

How does light intensity impact rate of transpiration (3)

A

greater light intensity –> more stomata open for photosynthesis

more stomata –> more transpiration

all stomata open –> further increase in light intensity won’t affect rate of transpiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q

How does temperature affect rate of transpiration (2)

A

greater temperature –> faster the particles in the air move

faster particles –> more water particles evaporate from leaf –> increases transpiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
84
Q

How does wind speed affect rate of transpiration (3)

A

increase in wind speed –> moves water particles surrounding leaf away

increases water potential gradient between inside and outside of leaf

increases rate of transpiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
85
Q

How does humidity affect rate of transpiration (3)

A

more humid –> more water in air

reduces water potential gradient between inside and outside of leaf

transpiration slows down

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
86
Q

Experiment for investigating rate of transpiration (4)

A

bubble potometer to estimate rate of transpiration

as transpiration occurs xylem sucks up more
water

bubble will move along capillary tube

measure distance moved by air bubble every minute to calculate rate of transpiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
87
Q

Define translocation

A

movement of sugars (sucrose) and amino acids in phloem of plant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
88
Q

Define source

A

where sugar is produced or supplied to plant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
89
Q

Define sink

A

where substance is used or converted to another substance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
90
Q

What is the source and sink in summer (2)

A

leaves are source

roots are sink

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
91
Q

What is the source and sink in winter (2)

A

roots are source

leaves are sink

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
92
Q

Where is xylem and phloem in root cross-section (2)

A

xylem is large hollow X centre

phloem on outer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
93
Q

Where is xylem and phloem on stem cross-section (2)

A

xylem on inside

phloem on outside

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
94
Q

Where is xylem and phloem on leaf cross-section (2)

A

xylem above

phloem underneath

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
95
Q

Why is active transport used to take in ions (2)

A

mineral ions in higher contents in plant than soil

root hair cells use active transport to get nutrients

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
96
Q

How does cohesion work in a plant (4)

A

water molecules are cohesive

tension created at top of xylem tube when water moves out of xylem cells

tension pulls water molecules up xylem into leaf

which pulls molecules out root cortical cells into root xylem tubes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
97
Q

State the type of cell through which water enters a plant

A

root hair cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
98
Q

State the type of energy required for photosynthesis

A

light energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
99
Q

Adaptation of xylem (4)

A

hollow - to reduce resistance/allow efficient
flow

large cross-sectional area/wide - to allow transport of large volume of water

lignin to provide support

waterproof to prevent water loss

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
100
Q

Explain how mineral ions enter a plant (2)

A

enter into root hair cell by active transport

moves against concentration gradient using energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
101
Q

Name simple sugars of carbohydrates(3)

A

glucose, lactose, sucrose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
102
Q

What is the purpose of carbohydrates

A

respiration to release energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
103
Q

Examples of carbohydrates (3)

A

potato, rice, pasta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
104
Q

Name polysaccharides of carbohydrates(2)

A

starch, glycogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
105
Q

Purpose of fats (3)

A

insulation - regulates body temperature

protect organs

energy storage - supply molecules for respiration (in case body does not have enough energy)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
106
Q

Fat sources (3)

A

salmon

almonds

avocados

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
107
Q

Purpose of proteins (2)

A

growth and repair of tissues

amino acids form enzymes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
108
Q

Protein sources (3)

A

meat

fish

cheese

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
109
Q

Result of excess carbohydrates(2)

A

obesity

tooth decay

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
110
Q

Name of protein deficiency

A

Kwashiorkor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
111
Q

Results of protein deficiency (3)

A

enlarged belly

small/wasting muscles

failure to grow properly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
112
Q

Purpose of Vitamin A

A

maintains the retina in the eye

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
113
Q

Vitamin A sources (3)

A

carrots

liver

butter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
114
Q

Purpose of Vitamin D (2)

A

helps bones absorb calcium

develops strong bones and teeth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
115
Q

Vitamin D sources (3)

A

fish

eggs

liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
116
Q

Vitamin C purpose(3)

A

keep lining of blood vessels healthy

strengthens immune system

healthy skin, teeth, gums

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
117
Q

Vitamin C sources (3)

A

citrus fruits

green vegetables

potatoes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
118
Q

Results of vitamin C deficiency (3)

A

weakened immune system

swelling/bleeding of gums

muscle and joint pain and tiredness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
119
Q

Calcium purpose (2)

A

making teeth and bones

involved in clotting of blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
120
Q

Calcium sources (3)

A

dairy products

fish

eggs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
121
Q

Iron purpose

A

make haemoglobin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
122
Q

Iron sources(3)

A

red meat, eggs, spinach

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
123
Q

Results of a vitamin d/calcium deficiency(2)

A

soft bones

curved leg bones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
124
Q

Define rickets/osteomalacia (2)

A

vitamin D deficiency

calcium deficiency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
125
Q

Define anaemia

A

iron deficiency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
126
Q

Result of iron deficiency (3)

A

red blood cells smaller than normal

less red blood cells

tiredness and short of breath

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
127
Q

Purpose of Water(3)

A

solvent for enzymes/food molecules

maintains osmosis correctly in cells

component of blood plasma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
128
Q

Fibre purpose

A

gives muscles of gut something to push against while food moves through alimentary canal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
129
Q

Examples of fibre (3)

A

cabbage

brown rice

wholegrain wheat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
130
Q

Fibre deficiency

A

constipation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
131
Q

fibre overintake

A

diarrhoea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
132
Q

Definition of digestion (3)

A

breakdown of large, insoluble food molecules to smaller, soluble food molecules

transported across membranes and used in metabolism

involves mechanical and chemical processes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
133
Q

Mouth purpose (3)

A

beginning of digestion

teeth work to break food apart

saliva contains amylase - breaks down carbohydrates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
134
Q

Bile purpose (2)

A

emulsify/break down fat

neutralize acid in food

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
135
Q

Location of fats

A

just below the skin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
136
Q

Marasmus definition

A

condition of low energy containing foods

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
137
Q

Result of Marasmus (2)

A

short for age

low body fat/muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
138
Q

Result of high proportion of saturated fats for diet (3)

A

increased cholesterol in arteries

increased blood pressure

increased risk of coronary heart disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
139
Q

Define ingestion

A

taking food and drink into the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
140
Q

Define absorption

A

movement of digested food molecules through intestine walls into blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
141
Q

Define assimilation (3)

A

movement of digested food molecules into cells to be used

digested food molecules become part of cells

or digested food molecules used to produce other molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
142
Q

Define egestion

A

passing out of food that has not been digested through the anus as faeces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
143
Q

Mouth purpose

A

break food down into smaller pieces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
144
Q

Salivary glands purpose(2)

A

produces saliva to moisten food so it can easily be swallowed

produces amylase to break down starch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
145
Q

Oesophagus purpose

A

moves swallowed food (bolus) from mouth to stomach by peristalsis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
146
Q

Define peristalsis

A

waves of muscle contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
147
Q

Stomach purpose(3)

A

protease (pepsin) secreted to digest protein

movement of stomach wall churn food into liquid

denature enzymes in harmful microorganism, killing them

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
148
Q

Liver purpose (3)

A

produces bile

removes excess glucose from blood and stores as glycogen

amino acids not used for making proteins broken down (urea) sent to kidneys for excretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
149
Q

gall bladder purpose(2)

A

stores bile

passes bile along the bile duct into small intestine to neutralize stomach acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
150
Q

pancreas purpose (2)

A

produces and secretes enzymes to the small intestine

produces lipase, amylase and protease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
151
Q

small intestine purpose (2)

A

secretions from gallbladder and pancreas complete digestion in the duodenum

digested food molecules and water are absorbed in the ileum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
152
Q

large intestine purpose

A

absorbs water from the remaining material

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
153
Q

anus purpose

A

egests faeces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
154
Q

Distance from mouth to anus

A

8 metres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
155
Q

Define mechanical digestion (2)

A

breaking food down physically into smaller pieces

without chemically changing food molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
156
Q

Examples of mechanical digestion (3)

A

biting and chewing action of teeth

bile emulsifying fats (breaking them into small droplets)

churning of stomach

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
157
Q

Define chemical digestion

A

breakdown of large insoluble molecules into small, soluble molecules using chemicals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
158
Q

Purpose of incisors

A

biting off food

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
159
Q

Shape of incisors

A

chisel-shaped

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
160
Q

Location of incisors

A

front of the mouth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
161
Q

Purpose of canines (2)

A

tear food

hold food (especially meat) to be chewed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
162
Q

Purpose of premolars(2)

A

cutting off tough foods

grinding foods (plant material)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
163
Q

Purpose of molars (2)

A

chewing foods

grinding foods (particularly plant material)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
164
Q

Location of molars

A

back of the mouth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
165
Q

Shape of molars

A

flat surface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
166
Q

Number of teeth (4)

A

4 incisors
2 canines
4 premolars
4-6 molars

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
167
Q

How does a tooth get corroded (3)

A

bacteria produce acids

acids corrode enamel and expose the dentine

causes pain in the nerves of the pulp cavity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
168
Q

How does plaque help bacteria

A

makes bacteria easier to grow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
169
Q

Solutions to plaque (2)

A

brushing teeth
avoiding foods high in sugar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
170
Q

Where is amylase produced (2)

A

salivary glands, pancreas

171
Q

Where is protease produced(2)

A

stomach wall, pancreas

172
Q

Where is lipase produced

A

pancreas

173
Q

Length of small intestine

A

over 6 m

174
Q

villi adaptations (3)

A

1 cell thick - short diffusion distance

supplied with blood capillaries - maintains concentration gradient with digested food and blood stream

lacteals transports lipids separately from rest of food molecules

175
Q

What nutrient does breast milk contain?

A

protein

176
Q

Define a balanced diet

A

A diet containing all nutrients in the right proportions

177
Q

What nutrient do children need in a higher proportion than adults?

A

protein

178
Q

Define malnutrition (2)

A

applies to a diet that causes health problems

can occur if one or more nutrients are too high/low a proportion in the diet

179
Q

Define constipation

A

A condition in which food moves too slowly through the alimentary canal

180
Q

Diseases that can be caused by constipation(2)

A

bowel cancer, diverticulitis

181
Q

Define starvation

A

occurs when there is too little energy provided by diet

182
Q

How does the body react to starvation

A

breaks down energy stores (first fat stores then muscle tissue) for respiration

183
Q

Result of starvation (2)

A

damage muscle tissue of heart

damage immune system

184
Q

First layer of the tooth (hard)

A

enamel

185
Q

Second layer of tooth

A

dentine

186
Q

3rd layer of tooth

A

pulp cavity

187
Q

What sticks tooth to gum

A

cement

188
Q

Shape of canines

A

sharp and pointy

189
Q

Purpose of mechanical digestion

A

creates greater surface area for enzymes and speeds up digestion

190
Q

Where is protease secreted

A

stomach

191
Q

Where is lipase secreted

A

small intestine

192
Q

Where is amylase secreted(2)

A

mouth

small intestine

193
Q

What are villi

A

finger-like protrusions on small intestine wall that increase surface area for nutrition absorption

194
Q

What are lacteals

A

lymphatic vessels of small intestine that absorb digested lipids

195
Q

Define mastication

A

process of mechanically breaking large pieces of food into smaller pieces using teeth

196
Q

Name the two parts of tooth structure (2)

A

crown

root

197
Q

Define the crown of the tooth

A

part of tooth that is visible above gum

198
Q

Define the root of the tooth

A

part of tooth that holds tooth in the gum

199
Q

Number of roots for incisors

A

1

200
Q

Number of roots for canines

A

1

201
Q

Number of roots for premolars

A

1

202
Q

Number of roots for molars

A

2 or 3

203
Q

Enamel purpose

A

protects softer dentine beneath

204
Q

Dentine purpose

A

covers pulp cavity

205
Q

What is external surface of crown

A

enamel

206
Q

Hardest substance produced in human body

A

enamel

207
Q

What is the pulp cavity made up of

A

a mixture of blood and nerves

208
Q

Cementum purpose (2)

A

connects tooth to jawbone

holds root of tooth in place

209
Q

Define the circulatory system

A

system of blood vessels

210
Q

Purpose of valves

A

ensure that blood circulates in one direction

211
Q

What is the heart

A

muscular organ

212
Q

Define arteries (2)

A

large blood vessels

carry blood away from heart

213
Q

Define capillaries (3)

A

tiny blood vessels

from network throughout ever tissue

connect arteries to veins

214
Q

Define veins (2)

A

large blood vessels

carry blood towards heart

215
Q

What happens when arteries get farther from the heart (2)

A

become narrower

divide more

216
Q

Define arterioles (2)

A

narrow vessels

connect arteries to capillaries

217
Q

Why is mammalian circulatory system called double circulation

A

blood passes through heart twice

218
Q

Why does blood leaving the right side of the heart have low pressure (2)

A

blood does not travel far to lungs

lower pressure stops damage to capillaries in lung

219
Q

Why does blood leaving the left side of the heart have high pressure

A

has to travel throughout body and back to heart

220
Q

Define the septum (2)

A

layer of tissue

separates right and left side of heart

221
Q

Name the 4 chambers of the heart

A

right atrium

right ventricle

left atrium

left ventricle

222
Q

Name of blood vessels which provide blood to heart (2)

A

coronary arteries

coronary veins

223
Q

How does deoxygenated blood flow into the heart (6)

A

blood arrives at heart from vena cava

enters right atrium

contraction of right atrium moves blood to right ventricle passing one-way valve

contraction of right ventricle moves blood to pulmonary artery and to lungs

valve at entrance of pulmonary artery closes to stop backflow into right ventricle

valve between ventricle and atrium closes to stop backflow into atrium

224
Q

How does oxygenated blood flow out of the heart (5)

A

enters left atrium from lungs through pulmonary vein

left atrium contracts and passes blood to left ventricle through valve

left ventricle contracts and moves blood out through aorta to body

valve at entrance of aorta closes to stop backflow into left ventricle

valve between atrium and ventricle closes to stop backflow of blood into atrium

225
Q

Define heart rate (2)

A

measure of how frequently the heart beats

measured in beats per minute

226
Q

Why may heart rate vary (4)

A

age - children usually have faster beat than adults

fitness - more muscle in heart hence pumps more blood

illness

drugs

227
Q

How is a heart attack caused

A

a full blockage of cholesterol

228
Q

What factors increase risk of blockage in coronary arteries (2)

A

high level of saturated fats in diet

smoking may damage artery lining

229
Q

Name of blood vessels associated with lungs (2)

A

pulmonary vein

pulmonary artery

230
Q

Name of blood vessels associated with kidneys (2)

A

renal vein

renal artery

231
Q

Define the vena cava

A

vein that carries blood to heart

232
Q

Define he aorta

A

artery that receives blood from heart

233
Q

Characteristics of arteries (3)

A

thick/elastic muscular walls

narrow central space (lumen)

high pressure

234
Q

Characteristics of capillaries (2)

A

thin walls - one cell thick

low pressure

235
Q

Characteristics of veins (3)

A

thin walled

large lumen

low pressure

236
Q

How does artery structure relate to its function (2)

A

thick walls don’t burst from high pressure

elastic walls maintain blood pressure

237
Q

How does capillary structure relate to its function

A

thin walls increase diffusion rate

238
Q

What substances does blood contain (4)

A

plasma

red blood cells

white blood cells

platelets

239
Q

Define plasma (3)

A

yellow coloured liquid

mainly consists of water

carries soluble nutrients, ions,
hormones, wastes (carbon dioxide), minerals throughout body

240
Q

Characteristics of red blood cells (2)

A

biconcave shape

no nucleus - allows them to carry more haemoglobin

241
Q

Define haemoglobin (2)

A

protein that transports oxygen

gives red blood cells red colour

242
Q

Define platelets (2)

A

small fragments of much larger cells

protects body from infection by causing blood to clot

243
Q

Function of white blood cells (2)

A

part of immune system

defend body against disease

244
Q

Define antibodies

A

chemicals which attack pathogens

245
Q

Define phagocytosis

A

killing pathogens by engulfing them

246
Q

Purpose of circulatory system (2)

A

deliver oxygen/nutrients (glucose) to cells for respiration

remove waste products e.g carbon dioxide

247
Q

Advantages of double circulation (2)

A

maintains concentration gradient by preventing oxygenated and deoxygenated blood from mixing

enables difference in pressure of blood exiting right and left side of heart

248
Q

What percentage does plasma make of total blood

A

55%

249
Q

What percentage do white blood cells/platelets make of total blood

A

less than 1%

250
Q

What percentage do red blood cells (erythrocytes) make of total blood

A

45%

251
Q

Features/Adaptation of Gas Exchange in humans (4)

A

large surface area

thin surface

good blood supply

good ventilation of air

252
Q

Uses of energy in living organisms (7)

A

muscle contraction

protein synthesis

cell division

active transport

growth

passage of nerve impulses

maintenance of body temperature

253
Q

Define aerobic respiration (2)

A

chemical reactions in cells

use oxygen to break down nutrient molecules to release energy

254
Q

Aerobic respiration word equation

A

glucose + oxygen –> carbon dioxide + water

255
Q

Balanced chemical equation for aerobic respiration

A

C6H12O6 + 6O2 –> 6CO2 + 6H2O

256
Q

Define anaerobic respiration (2)

A

chemical reaction in cells

break down nutrient molecules to release energy without using oxygen

257
Q

Anaerobic respiration releases more energy per glucose molecule than aerobic respiration. True or False?

A

False

258
Q

Word equation for anaerobic respiration in yeast

A

glucose –> alcohol/ethanol + carbon dioxide

259
Q

Word equation for anaerobic respiration in muscles

A

glucose –> lactic acid

260
Q

Balanced chemical equation for anaerobic respiration in yeast

A

C6H12O6 –> 2C2H5OH + 2CO2

261
Q

What happens during vigorous exercise (3)

A

lactic acid builds up in muscles and blood

causes cramps

causes oxygen debt

262
Q

How is oxygen debt removed after exercise (2)

A

fast heart rate transports lactic acid in blood from muscles to liver

deeper/faster breathing supplied oxygen to break down lactic acid

263
Q

Composition of inspired air (3)

A

21% oxygen

0.04% carbon dioxide

variable water contents (depends on environment)

264
Q

Composition of expired air (3)

A

16% oxygen

4% carbon dioxide

saturated in terms of water content

265
Q

What cells produce mucus

A

goblet cells

266
Q

Relationship between exercise intensity and rate/depth of breathing (7)

A

cells respire faster during exercise to provide necessary energy for muscle contraction

hence produce more carbon dioxide

carbon dioxide is acidic

can alter blood ph/disrupt enzyme activity

trigger blood ph sensors in brain

brain sends impulse to lungs to increase breathing rate/volume

removes excess carbon dioxide

267
Q

Which is more damaging?

An increase in carbon dioxide concentration or a decrease in oxygen concentration

A

increase in carbon dioxide concentration

268
Q

Experiment to investigate anaerobic respiration (5)

A

boil glucose solution to sterilise/remove oxygen (for anaerobic respiration)

cool temperature (otherwise yeast will die)

place layer of oil above glucose to prevent oxygen from entering

yeast will anaerobically respire producing alcohol and carbon dioxide

limewater will turn cloudy showing carbon dioxide is present

269
Q

Direction of air entering lungs (6)

A

mouth

larynx

trachea

bronchi

bronchioles

alveoli

270
Q

Purpose of mucus

A

traps microorganisms/dust particles breathed in

271
Q

Where are cilia/ciliated cells found (2)

A

trachea lining

bronchi lining

272
Q

Purpose of cilia (2)

A

sweep in co-ordinated motion

move mucus up trachea to back of mouth to be swallowed

273
Q

Define ventilation

A

movement of air across alveolar surface

274
Q

What are alveoli covered in

A

capillaries

275
Q

Alveoli Adaptations (4)

A

thin walls

moist lining

large surface area

high concentration gradient

276
Q

How does a moist lining improve gas exchange

A

gases dissolve before they diffuse

277
Q

Why does water vapour concentration increase in expired air

A

water evaporates from moist lining of alveoli due to warmth of body

278
Q

Components of cigarette smoke (3)

A

carbon monoxide

nicotine

tar

279
Q

How does carbon monoxide damage the body

A

reduces amount of oxygen blood can carry

280
Q

How does nicotine damage the body (3)

A

increases heart rate

puts strain on heart

increases risk of stroke

281
Q

How does tar damage the body (5)

A

causes breakdown of alveoli walls

causes alveoli to merge together

reduces surface area

leads to emphysema

increases chances of lung cancer

282
Q

Name 2 lung diseases

A

bronchitis

emphysema

283
Q

What disease can smoking cause

A

Chronic obstructive pulmonary disease

284
Q

How does bronchitis affect the body (2)

A

causes inflammation which narrows airways

causes mucus to block airways

285
Q

How does emphysema affect the body (3)

A

damages alveoli

air becomes trapped in alveoli

reduces gas exchange efficiency

286
Q

Name of gas exchange surface in humans

A

alveoli

287
Q

Name of the tissue that forms C-shaped structures in the wall of the trachea

A

cartilage

288
Q

Function of cartilage (2)

A

supports trachea

allows movement of air

289
Q

Describe the effects on the thorax of contraction of the diaphragm (2)

A

volume increases

pressure decreases

290
Q

Definition of homeostasis

A

maintenance of a constant internal environment within set limits

291
Q

Define hormones (2)

A

chemical substance produced by gland

alters activity of one or more target organs

292
Q

Where are hormones produced

A

endocrine glands

293
Q

How are hormones transported (2)

A

secreted into blood

carried around the body dissolved in plasma

294
Q

Effects of adrenaline (4)

A

increased pulse rate

increased depth of breathing

dilate pupils

causes liver and muscle cells to release glucose

295
Q

Where is adrenaline produced

A

adrenal glands above kidneys

296
Q

Functions of adrenaline

A

released in crucial moments during flight/fight response

297
Q

Hormones vs Nervous Systems form of transmission (2)

A

hormones is chemical

neurons = electrical impulses

298
Q

Where is glucagon secreted

A

pancreas

299
Q

Hormones vs Nervous Systems transmission pathway (2)

A

nervous = nerves

hormones = blood

300
Q

Hormones vs Nervous speed (2)

A

nervous faster

hormones slower

301
Q

Hormones vs Nervous duration (2)

A

nervous shorter

hormones longer (until hormone broken down)

302
Q

Hormones vs Nervous location of response (2)

A

nervous = specific

hormones = widespread though target organ may be specific

303
Q

Hormones vs Nervous what they consist of (2)

A

Nervous = neurons

hormones = glands

304
Q

Define the endocrine system

A

series of glands that produce/secrete hormones

305
Q

Define a gland

A

organ/tissue which produces/secretes chemical substances/hormones

306
Q

Glucoregulation steps for lack of glucose (4)

A

brain detects low blood glucose level

pancreas releases glucagon hormone into bloodstream

liver converts glycogen to glucose and releases to blood stream

blood glucose level rises

307
Q

Effect of increased pulse rate on adrenaline (2)

A

circulate blood more rapidly

deliver glucose and oxygen to muscle cells for more rapid contraction

308
Q

Effect of increased depth of breathing on adrenaline (2)

A

take more oxygen quicker

remove more CO2 quicker

309
Q

Effect of dilated pupils for adrenaline

A

better vision

310
Q

Effect of releasing glucose for adrenaline (3)

A

increase blood glucose concentration

more glucose for muscle respiration

release more energy for muscle contraction

311
Q

Glucoregulation steps for excess glucose (4)

A

brain detects high glucose blood levels

pancreas releases insulin hormone into bloodstream to liver

insulin causes liver to store glucose as glycogen

blood glucose level decreases

312
Q

Examples of homeostasis in sweat (3)

A

body temperature too high

sweat released from sweat glands

evaporation releases energy

313
Q

Examples of homeostasis in vasodilation (4)

A

arterioles near surface of skin dilate (widen)

more blood flows through capillaries

easier for heat to be transferred to skin

heat to environment by radiation and conduction

314
Q

Define negative feedback

A

stimulus change causes response which produces opposite change

315
Q

Homeostasis in vasoconstriction (4)

A

if body temperature too low arterioles near surface of skin constrict (narrower)

reduces amount of blood flowing through capillaries

warm blood kept deeper in skin

reduces heat loss by conduction

316
Q

Homeostasis reactions to low body temperature (2)

A

body hair raised by muscles in skin –> trap air as an insulator

muscles shiver - muscle contraction used to produce contractions which release energy and warm the body

317
Q

Which gland secretes testosterone

A

testes

318
Q

Which gland secretes insulin

A

pancreas

319
Q

Which gland secretes oestrogen

A

ovaries

320
Q

Example of positive feedback (childbirth) (5)

A

baby head pushes cervix

nerve impulses from cervix transmitted to brain

brain causes pituitary gland to produce oxytocin

oxytocin carried in blood to uterus

oxytocin causes uterus contractions and pushes baby to cervix

321
Q

Example of positive feedback in blood clotting (4)

A

break in blood vessel wall

clotting - platelets adhere to damage and release chemicals

clotting continues until break sealed

released chemicals attract more platelets

322
Q

What does the Human Nervous System consist of (4)

A

Central Nervous System

Specialised receptor organs (sense organs)

nerves of the peripheral nervous system

specialised effectors

323
Q

Central Nervous System (2)

A

processes nervous impulses from body + co-ordinates response

brain + spinal cord

324
Q

Nerves/Peripheral Nervous System

A

connect central nervous system to other parts of body

325
Q

Specialised Receptor Organs/Sense Organs (2)

A

contain receptor cells + senses stimuli

eye + ear

326
Q

Specialised effectors (2)

A

produce response to stimuli

e.g muscle contraction + hormone secretion

327
Q

Neurones (2)

A

specialised nerve cells

brain + spinal cord made out of neurones

328
Q

Neurone characteristics (4)

A

dendrites - branched endings make it easier to respond to stimulus + pick up impulses from other neurons

cell body - passes electrical impulse to axon

myelin sheath - insulation allows impulse to travel quickly

axon - long fibre to carry impulse to muscle

329
Q

Sensory neurons

A

neuron that links sense organs to central nervous system

330
Q

Relay neurons (2)

A

neuron within central nervous system

transmits electrical impulses from sensory neurons to CNS

331
Q

Motor neurones

A

neurones that connect CNS to effector

332
Q

Define effector

A

organ, tissue or cell that produces response

333
Q

Define reflex

A

automatic responses to stimuli

function is usually for protection

334
Q

Define stimuli

A

change in conditions

335
Q

Differences between neuron types (4)

A

motor + sensory neurones have longer axels

motor neuron - cell body is at top of dendrites

relay neuron - cell body is at middle of axels

sensory neuron - cell body is at side

336
Q

How reflex response generated (6)

A

receptor detects stimulus

receptor generates electrical impulse

sensory neurone carries electrical impulse to spinal cord

relay neurone conducts electrical impulse in spinal cord

motor neurone carries electrical impulse to effector

effector carries out response

337
Q

Involuntary responses (3)

A

reactions that happen automatically

fast reflex response - esential to survival

can bypass brain

338
Q

Voluntary Responses (2)

A

conscious decisions made by brain

slower

339
Q

Define eye

A

sense organ which responds to changes in light

340
Q

Components of the eye (5)

A

cornea + lens

pupil

jelly in eye

retina

optic nerve

341
Q

Cornea + Lens (2)

A

transparent - allow light to pass through

focus light so it falls on retina

342
Q

Pupil

A

hole that lets light fall through eye

343
Q

Jelly inside eye

A

maintains shape of eye so that distance from front to back of eye does not change

344
Q

Retina (2)

A

dark to absorb as much light as possible

contains light sensitive receptor cells

345
Q

Iris

A

controls amount of light entering eye

346
Q

Optic nerve

A

carries electrical impulses from retina to brain

347
Q

Blind spot in eye (2)

A

where optic nerve attaches to retina

no light-sensitive cells so cannot respond to light

348
Q

Reasons for Pupil Reflex (2)

A

light sensitive cells in retina can be damaged by intense sunlight - pupil responds to bright light by becoming smaller

light sensitive cells will not respond to darkness - pupils open to allow more light in eye

349
Q

How pupil reflex works (3)

A

iris contains circular + radial muscles

bright light - circular muscles contract, radial muscles relax, making pupil smaller

dim light - circular muscles relax, radial muscles contract, making pupil larger

350
Q

Accommodation for eye

A

adjustment to focus clearly on objects close or far to us

351
Q

How accommodation for eye works on distant objects (2)

A

light from distant objects is almost parallel and require less refraction

ciliary muscles relax - lens pulled into thinner shape by suspensory ligaments

352
Q

How accommodation for eye works for far objects (3)

A

light from far objects are more diverging - need more refraction to focus on retina

ciliary muscles contract - reduces tension on lens which widens

light is refracted more to focus image on retina

353
Q

Asexual Reproduction (2)

A

not necessary for 2 parents

cells from adult organism divide to produce offspring

354
Q

Bacteria using Asexual Reproduction (2)

A

when they are large enough genetic material copies itself exactly then cell splits in half

process repeats - can produce large numbers of identical bacteria

355
Q

Spore fungi using Asexual Reproduction (2)

A

hypha grows vertically once fungus has plentiful supply of nutrients

hypha contains many nuclei - releases spores into atmosphere

356
Q

Tubers using Asexual Reproduction (4)

A

tubers form from ends of stems

stems filled with starch

each tuber produces potato plants

potato plants give rise to mor tubers which produce more plants

357
Q

Advantages of Asexual Reproduction (3)

A

no need for parent to find mate

large number of organisms can be produced in short time

offspring produced are identical - should survive well in environment which parent grows

358
Q

Disadvantages of Asexual Reproduction

A

lack of variation - changes will affect all organisms, not able to move to different environments

359
Q

Define sexual reproduction (2)

A

fertilisation - nucleus of male gamete (haploid) fuses with nucleus of female gamete (haploid) to form zygote (diploid)

offspring genetically different from parents

360
Q

Advantages of Sexual Reproduction

A

variety of offspring - higher chance of species surviving in changing environments

361
Q

Disadvantages of Sexual Reproduction (2)

A

requires a second parent - takes time + energy + possibility of failure

longer to reproduce

362
Q

Stamen of Flower (3)

A

contain anthers

and stalk called filament

male part of flower

363
Q

Anthers of Flower (3)

A

contain cells that produce male gametes (pollen grain)

grain develops thick outer wall to protect male gamete as grain matures

once all pollen grains are mature, anther splits open + releases them

364
Q

Carpel of Flower (4)

A

female part of flower

style

stigma

ovary/ovules

365
Q

Stigma of Flower

A

where pollen lands during pollination

366
Q

Style of Flower

A

tube-like structure for pollen transport

367
Q

Ovary of flower (3)

A

base of carpel

protects female gamete

contains ovules

368
Q

Ovule of Flower

A

contains egg sac that surrounds egg cell (female gamete)

369
Q

Sepals of Flower (2)

A

green leaf-like structures

protect flower in bud

370
Q

Petals of Flower (2)

A

modified leaves

large + colorful to attract insects

371
Q

Sexual Reproduction of Plants Process (5)

A

male + female gametes produced

male pollen transferred to stigma for fertilisation

male + female gamete fuse to form zygote

zygote develops - forming embryo within a seed which protects embryo + provides nutrients for germination

seeds dispersed to grow away from parent

372
Q

Self-Pollination

A

pollen from same flower get to stigma

373
Q

Cross-Pollination

A

pollen from different flower gets to stigma

374
Q

Benefits of Self-Pollination (2)

A

quick

does not rely on pollinators

375
Q

Disadvantages for Self-Pollination

A

no genetic variation

376
Q

Insect Pollinated Plant Characteristics (6)

A

petals - large for insects to land + colourful to attract insects

pollen - sticky or spiky outer walls + heavier + produce smaller amounts of pollen

scented to attract insects

nectaries at base of flower produce nectar to attract insects

anthers - small + few + inside flower

stigmas - small + inside flower

377
Q

Wind-Pollinated Plants Characteristics (6)

A

petals - small to not inhibit pollen dispersal + inconspicuous (green)

pollen - light + large amounts produced + smooth outer walls

no scent

no nectar

anthers - large + hang out of flower so that pollen is easily dispersed

stigmas - large + feathery + hang outside flower to trap pollen

378
Q

Define Germination (3)

A

seed coat breaks open

embryo start to grow + develop into plant

379
Q

Conditions for successful germination (3)

A

temperature

moisture

oxygen

380
Q

Temperature for Germination (3)

A

seeds will not germinate until a suitable temperature reached

cold periods - seed lies dormant

too hot - seed may be killed

381
Q

Water for Germination (4)

A

required to swell seed + burst seed coat

activates hormones + enzymes

transport of materials for respiration + growth

required for metabolic + enzyme reactions

382
Q

Oxygen for Germination

A

aerobic respiration - requires oxygen, anaerobic respiration has slow energy rate + products are toxic

383
Q

Testes (2)

A

where sperm produced

outside body in scrotum to keep cooler - high temperatures = fewer sperm produce

384
Q

Sperm Ducts (2)

A

carry sperm from testes to penis

through prostate glands + seminal vesicles

385
Q

Stages of male reproductive system (7)

A

sperm ducts carry sperm from testes to penis

prostate gland + seminal vesicles produce liquid which sperm is able to swim - semen is mixture of sperm cells + fluids

semen moves along sperm duct to urethra

penis gets erect when man is sexually excited

muscle ring (sphincter) contracts at top of urethra - prevents urine entering urethra from bladder

penis enters vagina

ejaculation - contractions of muscles in penis send sperm into vagina

386
Q

Ovaries (3)

A

organs which produce eggs

located within abdominal cavity on either side of uterus

joined by oviducts

387
Q

Cervix (3)

A

lower end of uterus - leads into vagina

produces mucus which changes during menstrual cycle, allowing sperm to pass through some times and not others

keeps developing baby secure in uterus until birth

388
Q

Vagina

A

elastic muscular tube which receives sperm during intercourse

389
Q

Female period (3)

A

one ovary releases one egg

travels down oviduct to uterus

egg will be flushed from uterus (bleed) if not fertilised

390
Q

Sperm Cell size + number (2)

A

45 micrometres

over 100 million cells produced per day

391
Q

Egg cell size + number (2)

A

0.2 mm

ovary contains thousands but only one is released each month

392
Q

How does egg cell move

A

cilia inside oviduct move egg along

393
Q

Human Fertilisation Steps (5)

A

sperm deposited near cervix swim into uterus

swim along oviduct into egg while egg is traveling along oviduct

fertilisation occurs in oviduct - nucleus of sperm cell fuses with nucleus of egg cell forming zygote

zygote travels towards uterus - forms ball of 64 cells called embryo

embryo embeds in lining of uterus –> cell division + growth continue, gets nutrition from uterus lining

394
Q

Development of Fetus (3)

A

placenta developed + embryo becomes fetus

fetus develops inside amniotic fluid

fetus increases mass

395
Q

Amniotic Fluid (3)

A

fluid produced from amniotic sac

fluid protects fetus from physical damage

birth will happen soon when bag bursts before labour

396
Q

Placenta (4)

A

organ produced by growing fetus

allows constant exchange of material between mother and fetus

prevents pathogens from getting in fetus blood

fetus joined to placenta by umbilical cord

397
Q

How maternal and fetus blood do not mix

A

placenta + uterus wall have large number of blood vessels that dont touch

398
Q

What would happen if the blood from the mother mixed with the fetus

A

higher blood pressure in mother could damage fetus

399
Q

Diffusion of placenta (2)

A

dissolved nutrient that the fetus need diffuse from mother’s blood into fetus’ blood

metabolism waste products in fetus’ blood diffuse into mother’s blood

400
Q

AIDS (2)

A

disease of immune system caused by HIV

no cure for AIDS

401
Q

Causes of AIDS (3)

A

present in sexual fluids of infected person

can be passed through blood

can pass from mother to fetus - through placenta or through breastfeeding

402
Q

How is risk of AIDS reduced (3)

A

abstinence from sex

condom + femindom

limiting sexual partners to those without AIDS

403
Q

Chromosomes (2)

A

present in nucleus

made of DNA

404
Q

Genes (3)

A

small section of DNA which have code for different proteins

code for particular characteristics

genes on each chromosome copied during cell division

405
Q

Inheritance

A

passing on of characteristics from parent to offspring

406
Q

Alleles

A

different forms of genes causing variation in characteristics

407
Q

Diploid (2)

A

body cells

nucleus contains 2 sets of paired chromosomes - one set of chromosomes from mother + one from father

408
Q

Haploid (2)

A

gametes

nucleus of cells contain only one set of chromosomes

409
Q

Mitosis (3)

A

nuclear division - chromosomes copied then split

create genetically identical cells

2 daughter cells produced

410
Q

Examples of mitosis (2)

A

growth + repair of cells

how single-celled organisms reproduce : asexual reproduction

411
Q

Meiosis (2)

A

reduction divison where chromosome number halved from diploid to haploid

produce genetically different cells

412
Q

Example of Meiosis

A

production of gametes

413
Q

Homozygous

A

individual with 2 identical allelles for gene

414
Q

Heterozygous

A

individual with 2 different alleles for gene

415
Q

Dominant allele (2)

A

allele expressed in phenotype

if at least one allele is dominant it will be phenotype

416
Q

Recessive allele

A

allele that is not expressed in phenotype unless there are 2 copies present

417
Q

Genotype (2)

A

individual’s combination of genes

genotype influences phenotype

418
Q

Phenotype

A

individual’s combination of physical features

419
Q

Pedigree diagram unshaded square

A

unaffected male

420
Q

Pedigree diagram shaded square

A

affected male

421
Q

Pedigree diagram unshaded circle

A

unaffected female

422
Q

Pedigree diagram shaded circle

A

affected female

423
Q

Pure breeding

A

homozygous individuals breeding

Biology (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions