QUICK PRACTICE QUESTIONS

• Compare the structure of a red blood cell with the structure of a plant cell.


  Similarities

  - both have cytoplasm and cell membrane.

  Differences

  - red blood cells have no nucleus

  - red blood cells have no cell wall

  - red blood cells are a biconcave disc

  - red blood cells are smaller than plant cells.

  - red blood cells don't contain chlorophyll
• Describe two aseptic techniques the student should have used.


  sterilise equipment

  secure lid of Petri dish with tape
• Which cell structure in a leaf mesophyll cell is not found in a root hair cell?


  chloroplast
• Name the cells in a leaf that control the rate of water loss.

  guard cell
• Which change would decrease the rate of water loss from a plant's leaves?

  increased humidty
• Compare the structure and function of xylem tissue and phloem tissue.


  Xylem

  - xylem is made of dead cells

  - xylem is hollow

  - xylem transports water

  
  

  Phloem

  - phloem is made of living cells

  - phloem contains cytoplasm

  - phloem transports (dissolved) sugars

  - phloem is involved in translocation

  
  

  Both

  -made of cells
• The rate of water loss by a plant was lower at night time why?

  because less water loss at night as the stomata are closed because it is cooler
• Stage 3 in the cell cycle


  The cytoplasm and cell membrane divides to form two cells
• Give two advantages of using an electron microscope instead of a light

  microscope.

  higher resolution

  higher magnification
• An example of a tissue and organ in plant cells

  tissue: spongy mesophyll

  organ: leaf
• Why might scientists want to clone plants?

  To protect endangered plants from extinction
• The growth medium in Figure 2 helps the plants to grow.

  Name one substance in the growth medium.

  glucose
• what are ribosomes


  where proteins are made
• Root hair cells take up water from the soil.

  Explain one way in which the root hair cell is adapted to this function.


  large surface area for osmosis
• Explain why root hair cells contain mitochondria.

  respiration occurs in mitochondria, release energy energy used for active transport
• Name the structures inside the cell nucleus that contain DNA.

  chromosomes
• What type of substances are labelled A, C, G and T


  bases
• What is the name of the type of cell division that produces sperm cells?


  meiosis
• Explain how a transplant of bone marrow cells can help to treat medical

  conditions.

  bone marrow and differentiate into other types of cells, so will cure diseases where new cells are needed
• Difference between meiosis and mitosis

  1. Mitosis produces two daughter cells but meiosis produced four daughter cells

  2. Mitosis produces cells with 46 chromosomes meiosis produces cells with 23 chromosomes

  3. mitosis produces genetically identical cells, but meiosis

  produced genetically different cells
• similarities between meiosis and mitosis

  DNA doubles, increase in the number of mitochondria
• Give one way a malignant tumour differs from a benign tumour.


  (malignant tumours) spread to other tissues via the blood
• Name two other substances the cells need so they can grow and divide.

  glucose

  amino acids
• how do stents help CHD?

  They keep arteries open

  allowing air to flow through
• lock and key theory


  Startch (substrate) binds to the active site, because shape of the active site and substrate are complementary a chemical reaction occurs to produce smaller molecules
• Describe what happens to cells when a tumour forms.

  cells grow uncontrolllably
• Some types of cancer can cause the numbers of blood components in a

  person's body to fall to a dangerously low level.

  A person with one of these types of cancer may experience symptoms

  such as:

  • tiredness

  • frequent infections

  • bleeding that will not stop after the skin is cut.

  Explain how a very low number of blood components in the body can

  cause these symptoms.

  Tiredness

  • fewer red blood cells

  • so less haemoglobin

  • so less oxygen transported around the body. so less (aerobic) respiration can take place

  
  

  Frequent infections

  • fewer white blood cells so fewer antibodies produced

  
  

  Bleeding

  • fewer platelets

  • so blood does not clot as easily
• A person has a tumour blocking the tube leading from the gall bladder to

  the small intestine.

  Explain why this person would have difficulty digesting fat.

  less bile reaches the small intestine

  no emulsification of fat

  so smaller surface area for lipase to break down fat
• Explain the ways the man's body has responded to the exercise.

  heart rate increased to increase blood flowing to muscles to provide more oxygen for muscles and provide more glucose to muscles.

  
  

  Breathing rate is increased supplies more oxygen, more carbon dioxide removed.

  
  

  more oxygen to muscles needed for (increased) respiration and muscle contraction.

  
  

  anaerobic respiration occurs due to lack of oxygen which causes a build-up of lactic acid
• Vein

  Capillary

  Vein


  picture of all three

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

  has a thicker muscle tissue to push blood around the body

  
  

  narrow lumen to maintain high (blood) pressure
• A red blood cell: has haemoglobin, no nucleus

  Suggest how these adaptations help the red blood cell carry out its

  function


  N: to carry oxygen

  H: to bind oxygen
• Low amounts of platelets can lead to


  bleeding or bruising
• Explain how the human lungs are adapted for efficient exchange of gases by diffusion.


  (many) alveoli provide a large surface area.

  
  

  capillaries are thin which provided short diffusion path.

  
  

  breathing moves air in and out.

  
  

  good blood supply, to remove oxygenated blood quickly
• Explain the 'lock and key theory' of enzyme action.

  - enzyme binds to the substrate because they are complementary

  - (so) substrate is broken down (into products)

  - (so) products are released
• Describe how the students would find out if the liquid from the leaf

  contained glucose.

  1. Adds benedicts soltuon to a test tube boil if glucose is present the colours changes to brown/brick red
• Describe how the students would find out if the liquid from the leaf

  contained starch.

  Iodine solution if starch is present it changes colours to blue
• Explain why the leaf left in a cupboard with no light for two days did contain

  glucose but did not contain starch.

  1. Startch is converted to glucose used for respiration because there is not light to make new glucose by photosynthesis
• Describe how a vaccine would work to prevent gonorrhoea

  vaccines have dead or weakened form of pathogen

  White blood cells stimulated to produce antibodies

  Memory cells made

  On re-exposure antibodies are made very quickly
• What plant does aspirin originate from?


  willow