Question 1
The diagram below represent part of a cockroach gaseous exchange system.
- State the function of the part labelled M
- Suggest how the part N is adapted for gaseous
- How does the movement of oxygen in an insect and mammals from atmosphere to the tissue of the body differ
Answer
- Keep the trachea lumen open/prevented the trachea from collapsing
- Have moist surface, to aid diffusion of gases
- Insect – oxygen from atmosphere diffuse into the spiracle, Then trachea to the
tracheoles where it diffuse into the tissue/Not transported by fluid.
Mammals – Oxygen from atmosphere enters lungs, diffuses into blood to form oxyhaemoglobin then to heart where it is pumped to body tissues
Question 2.
The flow chart below shows blood transfusion pathway
- What five conclusions can you draw from the flow chart?
- Why is the knowledge of blood groups necessary before blood transfusion?
- Apart from knowledge of blood groups state two precautions that must be observed during blood transfusion
Answer
- 1. Blood group O is a universal donor as it donates to all other blood groups;
2. Blood group AB is a universal recipient as they receive blood from blood from all other groups.
3. Blood group A can receive blood from blood group O and A only.
4. Blood group B can receive blood from blood group O and B only.
5. Blood group O does not receive blood from other blood groups except group O - To avoid agglutination/clumping of red blood cells.
- Blood does not have pathogens.
The Rhesus factor matches
Question 3
Study the diagram below and answer the questions that follow
- Identify the part labelled Q
-
- What type of response is shown above?
- What is the importance of the above response
- Explain how the response exhibited by part Q occurs
- Name the plant hormone that is responsible for this response.
Answer
- Q - Tendril
-
- Haptatrophism/thigmotrophism
- Provides support to climbing plants
- When tendrils makes contact with a support, auxin hormones migrate to the opposite side of the contact this cause faster growth on that side, this cause tendril To curl/coil around the support
- Auxin
Question 4
The genetic disorder haemophilia is due to a recessive sex linked gene. A man who is haemophilia married a woman who is a carrier for the condition.
- Using the letter (H) to represent the normal condition and (h) for the haemophiliac condition
- What is the genotype of the man and woman
- Work out a cross between the man and woman
- What is the chance that both the first and second sons will be haemophiliac
- Hemophilia is more common in males than in female humans. Explain
Answer
- Using the letter (H) to represent the normal condition and (h) for the haemophiliac condition
- Man – XhY
Woman – XHXh;
- Man – XhY
- ¼ x ¼ = 1⁄16
- Y chromosomes does not have the corresponding allele; for the gene that determine or cause haemophilia/Y chromosome is almost genetically empty.
Question 5
The diagram below shows different groups of organisms and their biomass.
- Define the term biomass.
- Account for the decrease in biomass in the successive group of organisms
- Describe how energy from the sun is made available for Carnivore II
Answer
- Total dry mass,of living matter in an area at a particular time
- Fixed energy which support living matter decrease at each successible trophic level since energy is lost by respiration; undigested/unconverted material; hence less biomass supported at each.
- Energy from the sun trapped by green plants during photosynthesis; to produce chemical energy in form of carbohydrate; Green plants as producers are eaten by herbivores; herbivores eaten by carnivores I & II to obtain energy