random

Question 1

what does the waxy cuticle prevent in plants

Answer 1

water loss

Question 2

What does the upper epidermis allow in plants?

Answer 2

Transmission of light

Question 3

Describe the events of fertilisation that occur after the acrosome reaction. (3)

Answer 3

 fusion of sperm cell (membrane) with egg cell membrane (1)
 cortical granules release contents (into zona pellucida) (1)
 contents of cortical granules react with the zona pellucida /
zona pellucida { thickens / hardens } (1)
 fusion of { sperm and egg / haploid } nuclei (1)

Question 4

Describe the role of the CFTR protein in ensuring that the mucus produced in the lungs has the right consistency (3)

Answer 4

 chloride ions leave cells (through the CFTR channel protein) (1)
 sodium ions leave the cells (following the chloride ions) (1)
 increasing the solute concentration in the mucus (1)
 water moves out of the cells by osmosis (into the mucus) (1)

Question 5

Describe the light-dependent reactions of photosynthesis (5)

Answer 5

use of light (energy) to excite electrons in chlorophyll (1)
 {photolysis / splitting of water} to
produce oxygen, electrons and hydrogen ions (1)
 electrons used { in the electron transport chain / to replace those lost by chlorophyll } (1)
 generation of ATP / chotophosphorylation (1)
 reduction of NADP (1)

Question 6

In which part of the chloroplast do the light-independent reactions take place?
(1)

Answer 6

Stroma

Question 7

What is the name of the enzyme used by plants to fix carbon dioxide? (1)

Answer 7

RUBISCO (ribulose bisphosphate carboxylase/oxygenase)

Question 8

Once the blood vessel/endothelium is damaged, what is the first stage of atherosclerosis/ blood clotting?

Answer 8

Atherosclerosis: inflammatory response where WBCs move into artery(and increased risk of blood clot)
Blood clotting: Platelets attach to exposed collagen fibres

Question 9

What protein is released from platelets to convert prothrombin into thrombin?

Answer 9

Thromboplastin

Question 10

What enzymes does DNA replication use?

Answer 10

DNA helicase
DNA polymerase

Question 11

What enzymes does Protein synthesis use?

Answer 11

Transcription: DNA helicase, RNA polymerase
Translation: NA

Question 12

During atherosclerosis, a build up and hardening of what substances cause a plaque

Answer 12

WBCs, Cholesterol, Calcium salts, fibres