Cell-ebrities & cell warfare
What part of the cell controls its activities?
A) Cytoplasm
B) Nucleus
C) Vacuole
D) Ribosome
B) Nucleus ✅
Explain how light intensity affects the rate of photosynthesis.
A) Higher light = lower photosynthesis
B) Higher light = increased photosynthesis up to a limit
C) No effect from light
D) Photosynthesis only occurs at night
B) Higher light = increased photosynthesis up to a limit
What are the four bases found in DNA?
A) A, U, C, G
B) A, T, C, G
C) A, G, U, C
D) T, U, A, G
B) A, T, C, G
Describe the pathway of blood through the heart, starting from the vena cava.
A) Vena cava → right atrium → right ventricle → pulmonary artery
B) Vena cava → left atrium → left ventricle → aorta
C) Aorta → right atrium → vena cava → lungs
D) Pulmonary vein → left ventricle → lungs
A) Vena cava → right atrium → right ventricle → pulmonary artery
Name one abiotic factor.
A) Tree height
B) Predator numbers
C) Temperature
D) Seed dispersal
C) Temperature
Define diffusion.
A) Active movement against a concentration gradient
B) Passive movement of particles from high to low concentration
C) Movement of water molecules only
D) Bulk transport across membranes
B) Passive movement of particles from high to low concentration
Sketch and describe an experiment to measure the effect of CO₂ concentration.
A) Use a thermometer to measure temperature
B) Measure pH changes with cabbage juice
C) Use pondweed and count bubbles
D) Weigh the leaf before and after photosynthesis
C) Use pondweed and count bubbles
How many chromosomes are found in a normal human body cell?
A) 23
B) 46
C) 92
D) 22
B) 46
What is the function of bile? (3)
Mechanical digestion
Lipids - increase surface area
pH - make more alkaline
Which of these is not a greenhouse gas?
A carbon dioxide
B methane
C nitrogen
D nitrous oxide
C (nitrogen)
Describe the full immune response to a bacterial infection. (3)
White blood cells clone, make antibodies, memory cells form
Write the word equation for anaerobic respiration in yeast cells.
glucose ---------> ethanol + carbon dioxide;
Describe the process of transcription. (4)
1. DNA unzips / unwinds / eq (1)
2. mRNA / messenger RNA / eq (1)
3. mRNA copies code of DNA strand / DNA code copied / sequence copied / code carried by mRNA / eq (1)
4. in nucleus / leaves nucleus / eq (1)
5. mRNA goes to ribosome / eq (1)
How do you use a calorimeter (3)
Final temp minus start temp
Multiply by 4.2
Multiply by mass of water
Fully grown penguins are large, often weighing up to 30 kg. Most other birds are much smaller. Explain how being large helps the penguin to survive at very low temperatures. (2)
small surface area to volume (ratio);
2 less heat loss / less energy loss maintain body temp. / keep warm / fat insulation / eq;
Explain why the chances of rejection are lower is an organ comes from a close relative (3)
Genetically similar
Same antigens
No, reduced immune response
Describe the differences between an animal response to light and a plant response to light. (4)
(animal response)
1. uses nerves / neurones;
2. involves eyes / muscles / brain / eq;
3. electrical / uses impulses / eq
Cloning involves taking the .............................................................. out of a diploid body cell from the sheep that is to be cloned. This structure is then placed into an .............................................................. cell that has had its .............................................................. removed. Electricity is used to help the cell to .............................................................. by mitosis. This then develops into an .............................................................. which is then placed into the .............................................................. of an unrelated female. This female is known as the .............................................................. mother.
• nucleus (1)
• egg / oocyte / ovum (1) (Reject ovule)
• nucleus (1)
• divide (1) multiply
• embryo (1)
• uterus / womb (1)
• surrogate (1)
Some people are lactose-intolerant. Eating foods that contain lactose, such as milk, can make them ill. Explain why people who are lactose-intolerant are able to eat yoghurt without becoming ill. (2)
contains no lactose / lactose no longer in yoghurt /
yoghurt is lactose-free;
digested / broken down;
respiration / fermentation;
lactic acid;
Some farmers apply more nitrogen fertiliser and more water to their fields than are needed. Explain the biological consequences of applying more nitrogen fertiliser and more water than needed. (5)
water logged soil lacks oxygen
root cells cannot perform active transport/mineral ion cannot be absorbed
leaching occurs
algal bloom
blocks sunlight - no photosynthesis - algal die
decomposers - respiration - less oxygen - fish die
Prions are simple proteins. All known prion diseases can be fatal because the immune system does not recognise prions as foreign. Suggest two ways in which prions differ from viruses. (2)
1. no genetic material / DNA / RNA; 2. not recognised by immune system / eq; 3. smaller; 4. always fatal; 5.viruses have protein coat; 6. viruses can be used as vectors;
Describe the events that lead to seed formation. (5)
1. stigma; 2. pollen tube grows (down style); 3. into ovule / ovary; 4. enters via micropyle; 5. (male) nucleus / (pollen grain) nucleus / male gamete; 6. fertilisation / fuse / join / eq; 7. ovum / egg / (female) nucleus / female gamete; 8. ovule becomes seed; 9. ovule wall becomes seed coat / testa; 10. ovary becomes fruit
Describe how the chromosomes of a human cell produced by meiosis differ from the chromosomes of a human cell produced by mitosis (2)
haploid / half the number;
23 chromosomes / one of each pair;
Describe how the structure of a fish heart differs from that of a human heart. (2)
1. single circulation / no separate lung circulation / blood passes through heart once / blood in fish has to pass through two sets of capillaries / eq;
2. fish are smaller / fish have smaller heart / fish heart has thinner walls;
State three advantages of using biological control rather than pesticides (3)
1. no need to reapply / eq;
2. specific / only kill the pest / no or less effect on other organisms / no or less effect on food chain/web / eq;
3. no risk of resistance;
4. no bioaccumulation / no build up in food chain;
5. lasts longer / eq;