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Question 1

What kind of ribosomes does chloroplasts have?

Answer 1

= 70s chromosomes

Question 2

What do the pili on bacteria do?

Answer 2

= hair like structures that can bind to other bacteria

Question 3

what does the capsule do?

Answer 3

= slimy coat
= maintains moisture

Question 4

What do lysosomes do name the 2 roles?

Answer 4

= involved in phagocytosis
= reusing worn out/damaged organelles
=

Question 5

How does the lysosomes do its function?

Answer 5

= lysosomes contain digestive enzymes- acidic PH
= forms a vacuole and lysosomes fuse with the membrane of the vacuole and releases digesitibe ezmes yat digest the cell

Question 6

How are using lactase on beads useful?

Answer 6

= can be reused
= the milk does not need to be removed

Question 7

Why is glycogen a good source of energy?

Answer 7

= made from alpha glucose
= hydrolysed releases glucose
= can be used for respiration

Question 8

Determining the genome of the viruses could allow scientists to develop a vaccine. Explain how

Answer 8

= identify proteins that deprive from the genetic code
= identify the proteome and identify then the possible antigens that can be used

Question 9

Suggest and explain two further investigations that should be done before
this ADC is tested on human breast cancer patients.

Answer 9

= tested on healthy humans for side effects
= tested on other mammals
= considering a suitable dosage and concentration to be given to patients

Question 10

Explain how the active site of an enzyme causes a high rate of reaction.

Answer 10

= formation of enzyme substrate complex- lowers the activation energy- induced fit causes the active site to change- causes bonds to break

Question 11

(i) Humans and grasshoppers have very similar percentages of each base in
their DNA but they are very different organisms.
Use your knowledge of DNA structure and function to explain how this is
possible.

Answer 11

= Have different genes;
= (Sobases / triplets) are in a different sequence / order;
=(So) different amino acid (sequence / coded for) / different protein /
different polypeptide / different enzyme.

Question 12

Describe how a phosphodiester bond is formed between two nucleotides
within a DNA molecule.

Answer 12

= 2 nucleotides react- condensation reaction
= phosphodiester bond formed between the deoxribose sugar and phosphaye head- caaltsed by dna polymerae

Question 13

The gene for this polypeptide contains more than this number of bases.

Answer 13

= introns- non coding regions pf the gene

Question 14

difference between active and passive immunity?

Answer 14

Active involves memory cells, passive does not;
2. Active involves production of antibody by plasma cells /
memory cells;
3. Passive involves antibody introduced into body from outside /
named source;
4. Active long term, because antibody produced in response to
antigen;
5. Passive short term, because antibody (given) is broken down;
6. Active (can) take time to develop / work, passive fast acting.

Question 15

What important note is to be mentioned about antigens?

Answer 15

= FOREIGN protiens

Question 16

Why is it good for optical microscope samples to be thin?

Answer 16

= to allow more light to pass through
= to view single/multiple layers of cells

Question 17

The hydrostatic pressure falls from the arteriole end of the capillary to the venule
end of the capillary. Explain why.

Answer 17

= loss of water

Question 18

High blood pressure leads to an accumulation of tissue fluid. Explain how.

Answer 18

= high blood pressure means high hydrostatic pressure
= increased outwatds pressure in arteriole and reduced oressyre at venule end
= more tissue fluid formed less is absorbed

Question 19

The rise and fall in blood pressure in the aorta is greater than in the small
arteries.Suggest why.

Answer 19

= aorta is closer to the heart
= aorta has elastic tissue
= can strech and recoil

Question 20

What blood vessel carries blood at the lowest pressure?

Answer 20

= Vena cava

Question 21

For each of the following, give one way in which the structure or location in E. Coli differs from that in a eukaryotic cell.
= respirtory enzymes

Answer 21

= not found in mitochondria

Question 22

Explain how an epithelial cell is adapted for each of these functions:
(i) the active transport of substances from the cell into the blood
(ii) the synthesis of enzymes
(iii) rapid diffusion of substances from the lumen of the gut into the cytoplasm

Answer 22

= mitochondrua respire, prouces ATP, used to transport agaisnt the gradient

ii)
= ribosomes that synthesise protens, enymes needed

= microvilli increases surface area

Question 23

Mitochondria are organelles found in eukaryotes. Biologists think that mitochondria originated from prokaryotes. Suggest two structural features of mitochondria that provide evidence for this theory.

Answer 23

= contains DNA
= contains inner foldings
= doesnt have membrane bound rganelles

Question 24

(iii) Heating may affect the tertiary structure of a protein. Explain how.

Answer 24

= breaks the bonds holding the teritary structure in place

Question 25

Why are enzymes membrane bounded?

Answer 25

= prevent molecules from getting lost