BY2-June 2011 Flashcards
Name the type of life cycle undergone by the house fly.
Complete metamorphosis.
Name one feature that a cheetah has which allows the correct identification of each of its phylum and class.
Phylum-vertebral column/well developed brain/internal skeleton.
Class-endothermic/lungs/fur/double circulation.
The drastic reduction in the number of cheetah results in the loss of genetic diversity in the population. What term is applied to this?
Genetic bottleneck.
What biochemical method could have been used to determine that all cheetahs are closely related and what would the results show?
DNA fingerprinting/DNA profiling.
That the DNA shared between individuals is closely matched.
Describe the sequence of events which occur from the passing of the tapeworm eggs in human faeces to the infection of another human host.
Eggs/faeces eaten by pig.
Tapeworm eggs in muscle.
Undercooked infected meat eaten by human host.
Give three features of the tapeworm which show how the parasite is adapted to its way of life.
Suckers and hooks. Thick cuticle. Secretes chemicals which inhibit the digestive enzymes of host. Large surface area to volume ratio. Large number of eggs produced.
What two simple precautions can be taken to avoid infection by the pork tapeworm?
Ensure meat is thoroughly cooked.
Do not spread untreated sewage on land.
Give two functions of stomata in leaves.
Allows gas exchange of O2 and CO2.
Control water vapour loss.
Explain how the flow of water into guard cells leads to the opening of stomatal pores.
Pumping of K+ ions into the guard cells.
Starch converted to malate.
Conversion lowers water potential.
Water flows in by osmosis down water potential gradient.
Guard cells become turgid.
Inner wall if guard cell is thicker.
So guard cells curve away from each other.
Explain why cyanide has an effect on the opening of stomatal pores.
Cyanide inhibits respiration.
No ATP synthesis.
So can’t actively pump K+ ions into guard cells.
What type of plant is a Nymphaea?
Hydrophyte.
State 3 adaptations of Nymphaea for living in an aquatic environment and state why each is important.
Large air spaces for buoyancy.
Stomata on upper surface so allowing gas exchange with air.
Little support tissue as buoyed by water.
Thin cuticle as little water vapour loss.
Give one feature of a dry weather plant which shows how its adapted to it’s environment.
Rolled leaves.
Thick cuticle.
Sunken stomata.
Name the enzyme used in an experiment involving bile salts and lipids.
Lipase.
Explain the colour change in the experiment of bile salts, from pink to colourless.
Hydrolysis of lipids.
Releasing fatty acids.
Causing more acid pH.
