Paper 4 Flashcards Preview

Biology > Paper 4 > Flashcards

Flashcards in Paper 4 Deck (28):
1

Explain how food is moved along the oesophagus (2 marks)

Muscles contract and peristalsis occurs

2

Then the carbohydrate found in plant cell walls

Cellulose

3

Why does a horse need vitamin C? (1 mark)

Help skin and gums

Prevent scurvy

Helps connective-tissue

protects against infection

Helps immune system

4

Name one gas used by flies and one gas produced by flies

Gas used: oxygen

Gas produced: carbon dioxide

5

Suggest how an insect pest could affect crop yield (3 marks)

Reduce yield/eat crop/eat leaf
Therefore less leaf/less surface area/trap light/absorb CO2
Therefore less photosynthesis

6

Explain why farmers often spray pesticide onto their crops. (2 marks)

Kills/destroys pests
Increases yield/reduces crop loss/prevent eating crop

7

Give two disadvantages of using pesticides

Kills other insects

Affects consumer/disrupts food chains

Short lasting

Effect on humans

8

Then one substance that would not be removed from the body if the kidneys failed

Urea/water/salt/urine

9

Why would damage to red blood cells lead to problems?

Less oxygen transport

10

Name the cells in the body that produces antibodies

White blood cells

11

Explain why paralysis of the breathing muscles is dangerous (3 marks)

No contraction of the diaphragm/intercostal muscles
No volume/pressure changes
No Air/gas/oxygen in
No carbon dioxide out
Less oxygen to body/blood/cells
Less respiration/energy

12

When a sample of water is tested, its water quality is measured by finding out how much of it oxygen is used up when it is Sealed in the dark for five days. The oxygen is used by microorganisms breaking down organic matter in the water.

Suggest why these sealed samples are kept in the dark (2 marks)

Prevent photosynthesis which produces oxygen

13

Describe and consequences of smoking on the human lungs (5 marks)

Tar
Coughing
Damage to cilia
Mucus build up
Bronchitis
Bacteria/microorganism
Infection
Lung cancer
Blockage to tubes/difficulty in breathing
Emphysema
Reduced surface area/ damage to alveoli/ less gas exchange

14

Burning fossil fuels returns carbon dioxide to the atmosphere.

Explain how increased use of fossil fuels could affect the environment. (5 marks)

Greenhouse gas

Greenhouse effect

Global warming/track Pete

Ice caps melting

Sealevel rising

Migration/death/loss of species

Climate change

15

Explain what is meant by the term insect pollinated (2 marks)

Transfer of pollen

From anther/stamen of stigma (by insect)

16

In which cells of a leaf would you expect to find the most chlorophyll?

Palisade

17

The circulation system of a human is known as a double circulation system. Suggest why the circulation system of a fish is known as a single circulation system (2 marks)

Blood passes through the heart once
Heart to gas exchange organ to body/ not to lung
In humans blood to lungs and the body

18

Explain the response of the human heart to adrenaline (3 marks)

To prepare body for physical activity
Stress
Adrenal glands
Heart beats faster

19

The DNA molecule is known as a double helix.

Explain what is meant by the term double helix

Two strands
coiled/interweaving

20

Genetic modification uses enzymes to cut enjoying sections of DNA.

Name the enzyme used to cut DNA at a specific sites

Restriction

21

Genetic modification uses enzymes to cut enjoying sections of DNA.

Name the enzyme used to join two sections of DNA

Ligase

22

What name is given to an organism as been genetically modified to contain DNA from a different species?

Transgenic

23

Maimone human hormone that is produced by genetically modified bacteria

Insulin

24

Give one advantage of using genetically modified bacteria to produce insulin

Can be made quickly/in large quantities

25

Very small pieces are cut from the tips of stems or side shoots of a plant. When these pieces have been removed they are called…….They are cut to a size of about 0.5 to 1 mm. Thhey are then placed in a…...median containing…….And……., Which helps the pieces to grow into small plants. When the small plants have grown roots they are transferred to a greenhouse. They are grown in pots containing……., And conditions such as…….And…….Can be controlled. The small plant's produced are called………., Which means they are genetically………

Explants
Nutrient/growth
Nutrient/minerals
Nutrient/minerals
Compost/soil
Temperature/carbon dioxide flashlights
Temperature/carbon dioxide flashlights
Clones
Identical

26

Which part of the central nervous system does the optic nerve go to?

Brain

27

The vitreous humour helps to keep the retina pressed against the back of the eye. However, as a result of a severe blow to the head, sometimes the retina can come away from the back of the eyes.

Suggest how this detached retina would affect vision. Explain your answer (2 marks)

Blurred/not clear

As retina wrong distance/not focusing

28

Describe what is meant by a mutation and explain the effects a mutation could have in a population of organisms

Change/damage/mistake to genetic material

Passed on/inherited

Rare/random

Alters characteristic

Harmful

Few beneficial

Causes a natural selection/revolution