bio paper 1 mistakes

• Name one type of cell in a potato plant that does not contain chloroplasts.

  root hair cell
• Where is protein digested in the human digestive system?

  stomach
• what does high amounts of fat in diet lead to

  obesity- type 2 diabestes, narrowing of arteries- chd, may need stents
• what can high amounts of cholesterol in diet lead to

  narrowing of arteries- chd, may need a stent, may need to take statins
• what is fibre used for in a diet

  for digestion/ prevents constipation
• why is A thin layer of onion epidermis is used when preparing a slide


  to help see individual cells
• why is Iodine solution is added to the onion epidermis.

  to stain/ see parts of the cell
• magnification=


  image(on sheet)/ real
• cm to micrometres


  x1000
• Onion cells can be seen using an electron microscope.

  Give two ways onion cells would look different when seen using an electron

  microscope

  seem more magnified/ bigger, more sub cellular structures seen
• Why a tree might die if the roots of the tree are damaged

  1. Less absorption of water

  2. Less water so lower rate of photosynthesis, so less glucose produced, for respiration / energy release, so less cellulose produced so fewer cells walls /cells made, so fewer amino acids produced to make new proteins

  3. Cells lose turgidity

  4. Less absorption of (named) ions / minerals, fewer nitrates so fewer proteins made for growth, fewer magnesium ions so less chlorophyll produced, so lower rate of photosynthesis

  5. Damage to phloem, less transport of sugars to root cells, for respiration / energy release

  6. Damage to xylem, less water transported (to cells), fewer nitrates reach cells, so fewer proteins made for growth, fewer magnesium ions reach cells, so less chlorophyll produced, less magnesium / chlorophyll so lower rate of photosynthesis

  7. Less anchorage
• The larvae of the hornet moth form when fertilised eggs divide by mitosis.

  Describe how mitosis produces two genetically identical cells.

  genetic material / DNA /

  chromosomes is doubled /

  replicated / copied / duplicated

  the (replicated) chromosomes

  are pulled / moved apart

  cytoplasm divides into two

  (cells)

  or

  cell membrane divides to form

  two cells

  the set of chromosomes in each

  new cell are identical (to one

  another)
• Describe how the alveoli and the villi are adapted to increase absorption.

  both have a large surface area

  o to maximise diffusion

  • both have thin walls or have walls that are one cell thick

  o to reduce diffusion distance / time

  • both are in close proximity to blood supply

  o to reduce diffusion distance / time

  • both have a good blood supply or both have a capillary network

  o to maintain concentration gradient

  • villi have microvilli

  o to (further) increase surface area

  • cells of villi contain many mitochondria

  o for active transport
• Explain how a vaccine for HIV could work to prevent a person developing

  HIV infection.

  inactive HIV / virus is injected

  (into bloodstream / muscle /

  body)

  white bloods cells produce

  antibodies (against inactive

  virus)

  (if infected with HIV) correct /

  specific antibodies are produced

  quickly

  antibodies destroy the (active)

  virus / HIV
• Describe how the monoclonal antibody for HIV can be produced.


  HIV / antigen / protein injected

  into mouse

  extract / collect (mouse)

  lymphocytes that make a

  specific antibody to HIV /

  antigen / protein

  lymphocytes are combined with

  a tumour cell to create a

  hybridoma

  (hybridoma) cloned to create

  many cells that produce the

  antibody
• Suggest how the monoclonal antibody for HIV helps to prevent a person infected with

  HIV developing AIDS.

  monoclonal antibody is

  complementary / specific to HIV

  antigen

  monoclonal antibodies attach to

  (all the) HIV antigens

  (so) HIV cannot bind to (human)

  cell

  or

  (so) HIV genetic material cannot

  enter (human) cell
• Red blood cells


  Specialised animal cells
• Red blood cell


  • No nucleus
  • No cell wall
  • Biconcave disc shape
  • Contains haemoglobin
  • No chlorophyll
  • No chloroplasts
  • No (permanent) vacuole
  • Smaller than plant cells
• Plant cell


  • Has nucleus
  • Has cell wall
  • Many different shapes
  • No haemoglobin
  • May contain chlorophyll
  • Has chloroplasts
  • Has (permanent) vacuole
  • Larger than red blood cells
• What are the two products of anaerobic respiration in plant cells?


  ethanol, carbon dioxide
• Amylase is a polymer of smaller molecules.

  Name the type of smaller molecule.

  amino acids
• The student investigated the effect of temperature on amylase activity.

  Describe how the student could extend the investigation to determine the effect of a

  different factor on amylase activity.

  keep temperature constant

  (but) change named factor and

  test a range of values of named

  factor
• Xylem


  • Made of dead cells
  • Does not have pores in end walls
  • Hollow or does not contain cytoplasm
  • Contains lignin
• Phloem


  • Made of living cells
  • Has pores in end walls
  • Contains cytoplasm
  • Does not contain lignin
• Both xylem and phloem are made of cells
• Both xylem and phloem are tubular
• Function of xylem


  • Transports water / mineral ions
  • Involved in transpiration
  • Transports unidirectionally
• Function of phloem


  • Transports (dissolved) sugars
  • Involved in translocation
  • Transports bidirectionally
• Both xylem and phloem transport liquids / substances throughout the stem / leaves / roots / plant
• Types of cancer that may cause symptoms


  • Tiredness
  • Frequent infections
  • Bleeding that will not stop after the skin is cut
• How a very low number of blood components in the body can cause these symptoms

  1. Tiredness:

  2. Fewer red blood cells

  3. Less haemoglobin

  4. Less oxygen transported around the body

  5. Less (aerobic) respiration can take place

  6. More anaerobic respiration takes place

  7. Less energy released for metabolic processes

  8. Lactic acid produced (during anaerobic respiration) causes muscle fatigue

  9. Frequent infections:

  10. Fewer white blood cells / phagocytes / lymphocytes

  11. Fewer antibodies produced or less phagocytosis

  12. Fewer pathogens / bacteria / viruses killed

  13. Bleeding:

  14. Fewer platelets

  15. 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.

  no / less bile reaches the small

  intestine

  (so) less / no emulsification of

  fat

  (so) smaller surface area for

  lipase to break down fat

  pH of small intestine is not

  neutralised / alkaline

  (so) lipase is not at its optimum

  pH to break down fat
• Human lungs


  • Provide a large(r) surface area (: volume)
  • Capillaries are thin or alveoli / capillary walls are thin or one cell thick
  • Capillaries are close to the alveoli
  • Breathing (mechanism) moves air in and out or lungs are ventilated
  • Large capillary network (around alveoli) or good blood supply
• Efficient exchange of gases by diffusion


  1. Bring in (fresh) oxygen

  2. Remove carbon dioxide

  3. Maintain a concentration / diffusion gradient

  4. Remove oxygen(ated blood) quickly

  5. Bring carbon dioxide to the lungs quickly
• Alveoli


  Provide a large(r) surface area (: volume)
• Short diffusion path (for oxygen / carbon dioxide)


  Provided by thin capillaries or alveoli / capillary walls being thin or one cell thick
• Breathing (mechanism) moves air in and out or lungs are ventilated
• Maintaining a concentration / diffusion gradient
• Large capillary network (around alveoli) or good blood supply
• A scientist noticed that in one area the gorse plants had yellow leaves and had stunted growth