B3 Knowledge Test Answers

  1. Where there is not enough food for the population of the world
  2. Reducing the number of pest species using a coordinated treatment of different pest control methods.
  3. Producing new plants by using the natural technique of cross breeding two plants.

Advantages / Disadvantages
Biofuels are renewable / Requires large amount of land
Biofuels are carbon neutral (the Carbon Dioxide they take in during their growth is equal to that they release when burned) / This reduces the amount of land that be used for growing crops
  1. Agrobacterium plasmid modified. Plasmid inserted into Agrobacterium, Agrobacterium infects plant cell, plant genome incorporates plasmid into DNA, Plant starts to produce new protein.

Advantages
Less insecticide has to be used
Reduced damage to the environment through less insecticide use
Higher yields because of less insect damage
  1. The flavonoids were found the help mice with cancer live longer. This might be useful for humans.
  2. Arms shortened, brain size increased
  3. By dating the layers of rock they are found in.
  4. mtDNA is more abundant that nuclear DNA.

mtDNA is less likely to have degraded over time.

mtDNA more useful than fossil evidence for tracking evolution.

  1. Has an acrosome containing enzymes; Has a haploid nucleus containing one set of the genetic material; Middle section contains mitochondria to release energy; Has a tail for motility
  2. Has cytoplasm to provide nutrients; Has a haploid nucleus containing one set of the genetic material; Immediately after fertilisation it undergoes changes to the cell membrane to block entry of other sperm

Fertility Treatment / Advantage / Disadvantage
Donation of eggs / Allows women who do not have viable eggs to have a baby. Mother carries the baby. / Some women react badly to the hormones used to make them ovulate
In vitro fertilisation / Uses the mother and fathers own sex cells
Natural mother carries the baby / Babies often born prematurely which can cause problems
Use of surrogate mothers / Allows a couple to have a baby who otherwise may not be able to. / Handing the baby over can cause problems
Use of hormones / Helps the woman conceive naturally. / Some women react badly to the hormones. Babies often born prematurely which can cause problems. Often results in multiple births.
  1. XX XY
  2. .
  1. A response to changing day length
  2. Reproduction, growth, germination
  3. A biological rhythm that takes place over about a day
  4. Water, urea, carbon dioxide
  5. Breakdown of Amino Acids

  1. Dialysis, transplant
  2. Takes a long time, expensive
  3. .

  1. .
  2. Filtration of small molecules under high pressure
  3. Regulation of water to form urine
  4. Pituitary gland
  5. Kidneys absorb more water and produce a small volume of concentrated urine
  6. The alteration of natural biomolecules using science and engineering to provide goods and services.

Condition in the fermenter / Why needed? / Effect on microbial growth
Aseptic conditions / To prevent contamination and spoilage
Nutrients / For microbial division and growth / More nutrients means more microbial growth
Optimum Temperature / To ensure maximal growth because of maximal enzyme activity / As temperature increases, microbial growth will be faster until the optimum is reached, after which growth rates will fall and stop
Optimum pH / To ensure maximal growth because of maximal enzyme activity / As pH gets further from the optimum, microbial growth will slow
Oxygenation / To ensure aerobic conditions for respiration / Aerobic conditions favour microbial growth
Agitation / To mix the liquid to ensure even distribution of nutrients, oxygen etc. / Optimal growth is ensured.
  1. Rapid population growth, ease of manipulation, production independent of climate, uses waste products from other industrial processes.
  2. Mycoprotein is made in 40 metre high fermenters which run continuously for five weeks at a time.

The fermenter is sterilised and filled with a water and glucose solution. Then a batch of Fusariumvenenatum, the fungi at the heart of Mycoprotein, is introduced.

A continuous feed of nutrients, including potassium, magnesium and phosphate as well as trace elements, are added to the solution. The pH balance, temperature, nutrient concentration and oxygen are all constantly adjusted in order to achieve the optimum growth rate.

The organism and nutrients combine to form Mycoprotein solids and these are removed continuously from the fermenter .

The Mycoproteinis heated to 65°C to breakdown the nucleic acid. Water is then removed leaving the Mycoprotein.

The Mycoprotein is then mixed with egg and seasoning to help bind the mix. It is then steam cooked for about 30 minutes and then chilled, before being chopped into pieces or mince.

The product is then frozen. This is a crucial step in the process because the ice crystals help to push the fibres together, creating bundles that give Mycoprotein its meat-like texture.

  1. Bacteria convert lactose --> lactic acid. Temperature, pH, type of milk, nutrients in the milk, type of bacteria used
  2. Invertase used to produce soft centered sweets, chymosin used to make vegetarian cheese.
  1. Attached to an inert material to aid recovery after use.
  2. To attract/find a suitable mate
  3. Deer – ensures variation and chances of survival increased.
  4. increased chance of survival, increased chance of parents genes being passed on.
  5. Innate – inborn. E.g. reflexes that help survival. Increasing the chances of survival and genes being passed on.

Imprinting – animals becoming attached to the first thing they saw and interacted with.

  1. Operant conditionning involves a reward, classical conditionning is learned to associate a specific behaviour with an unrellated stimuli
  2. Visual, sound, chemical (pheromones)
  3. Fosseyinterprettedgorillas communications, Goodall found chimps hunt in groups and use tools.
  4. Evolved brightly coloured chemicals in petals.

Produce chemical scents.

Ethylene is produced by Accacia trees. This promotes other trees nearby to produce distasteful poisonous chemicals to deter other insects even before they start to attack.

  1. Where two species change together over time
  2. Where a change in one factor causes an opposite change to keep things constant.
  3. Oestrogen and Progesterone
  4. Menstruation, uterus lining thickens, ovulation
  5. Corpus luteum continues to release progesterone to keep this hormone level high and maintain the uterus lining
  6. Progesterone
  7. LH
  8. Developed the swan necked flask to stop bacterial contamination of cultures
  9. Asprin, quinnine, digioxin
  10. A disease causing microorganism
  11. Reduces food supply
  1. Took pus from cowpox blister and rubbed it into skin, boy got a small fever, repeated with the smallpox blister, no symptoms experienced
  2. The cowpox pathogen is a similar shape to smallpox pathogen so the memory lymphocyes recognise it a produce antibodies quickly.
  3. Harmless antigenic material injected, antigens trigger immune response which results in antibody production, memory lymphocytes remain.
  4. Harmless antigen or pathogen injected

Antigens trigger immune response and production of antibodies

Antigens trigger production of memory lymphocytes

Advantages of Immunisation / Disadvantages of Immunisation
A child can become immune to a disease without suffering from it / Some mild symptoms of the disease associated with immunisation
Reduces chances of long term harm from dangerous diseases e.g. measles, mumps, rubella / Swelling or redness around the injection site
If enough children are immunised, the disease becomes so rare – herd immunity / Allergic reaction
  1. Remain in blood, immediately produce antibodies if the same antigen is detectedso the person doesn’t get ill.
  1. Pregnancy testing, location of blood clots and cancerous tumours, drug and radiotherapy treatment of cancer