exam qs 2020

• Cell wall : to strengthen the cell
• The algal cell is green. Which part of the algal cell makes it green in colour?

  Chloroplast
• Cell membrane : controls transports of substances into the cell
• Mitochondria: where energy is released
• Ribosomes : where proteins are made
• Which process makes two identical new body cells for growth and repair?

  Mitosis
• Cell cycle :

  1. The cell grows and the chromosomes replicate
  2. One set of chromosomes is pulled to each end of the cell
  3. The cytoplasm and cell membrane divide to form two new cells
• The chromosomes contain the genetic material. Name the chemical which the genetic material is made from.

  DNA
• The genetic material is made of many small sections. Each section codes for a specific protein. What is one section of genetic material on a chromosome called?

  A gene
• Stem cells are cells which have not yet been specialised to carry out a particular job. Bone marrow cells are one example of stem cells. Explain how a transplant of bone marrow cells can help to treat medical conditions

  (bone marrow) cells differentiate into many / other types of (named) cell (so) will cure diseases where new cells are needed or will cure diseases where cells are damaged
• The human body can defend itself against microorganisms that cause disease. Viruses are one type of microorganism that cause disease. Name one type of microorganism that causes disease in humans

  • Bacteria
  • Fungi
  • Protists
• Which two defence systems prevent microorganisms infecting the human body?

  hydrochloric acid is produced by the stomach the skin is a barrier covering the whole body
• If microorganisms enter the human body the immune system can destroy the microorganisms. How does the immune system destroy microorganisms?

  white blood cells engulf the microorganisms
• In a vaccine the measles virus is weakened . If the measles virus enters the body after vaccination the immune system reaction will be fast .
• How is the measles virus spread from one person to another?

  by coughs/ sneezes
• Suggest one reason why some of the children did not develop chickenpox.

  • they had been vaccinated
  • they already had antibodies
  • they were immune
  • they had had it before
• One mother gave antibiotics to her child who had chickenpox. Suggest why this child did not recover more quickly than the other children who had chickenpox.

  antibiotics do not kill viruses
• How will the poisonous berries help the deadly nightshade plant to survive?

  will stop animals / herbivores eating it
• Suggest how the gorse plant is adapted to defend itself?

  thorns / spikes / spines / prickles (to stop animals / herbivores eating it)
• What are two uses of glucose in the gorse plant?

  for respiration to store as starch
• nitrate ions are needed) to make proteins / amino acids which are needed for growth / enzymes / new cells
• Which two factors must the doctors test the drug for in the trial

  • dosage
  • toxicity
• What are the tablets made from sugar called?

  Placebo
• Explain how the structure of an artery is related to its function

  • thick(er) (muscle) walls / tissue to push blood (all) around the body
• A red blood cell: • has no nucleus • contains a red pigment called haemoglobin. Suggest how these adaptations help the red blood cell carry out its function

  (no nucleus) more space for haemoglobin / oxygen (has haemoglobin) to bind / carry oxygen
• What is the liquid part of the blood called?

  Plasma
• Carbon dioxide + water → glucose + oxygen
• Describe how energy for the photosynthesis reaction is gained by plants.

  (light) is captured / trapped / absorbed by chlorophyll / chloroplasts
• What is meant by the term diffusion?


  movement / spreading out of molecules / particles from (an area of) high(er) concentration to (an area of) low(er) concentration
• Name the process by which water molecules enter the root hair cell.

  Osmosis
• Nitrate ions need a different method of transport into the root hair cell. Explain how the nitrate ions are transported into the root hair cell.

  active transport (because) energy is needed (to move nitrate ions) from a low(er) concentration (in the soil) to a high(er) concentration (in the root / cell