Question 1
Name the branches of biology that deal with study of
a) Inheritance and variations
b) Chemical changes inside living organisms
c) The relationship between organisms and their environment
d) Insects
Answer
a) Genetics
b) Biochemistry
c) Ecology
d) Entomology
b) Biochemistry
c) Ecology
d) Entomology
Question 2
a) State two functions of cell membrane
b) Name the cell organelles that would be abundant in
I. Skeletal muscles
II. Palisade cells
III. Fat cells
Answer
a) - Enclose the cell contents
- Control or regulate entry and exit of substances in and out of the cell
b) I. Mitochandria
II. Chloroplasts
III. Smooth endoplasmic reticulum
- Control or regulate entry and exit of substances in and out of the cell
b) I. Mitochandria
II. Chloroplasts
III. Smooth endoplasmic reticulum
Question 3
Explain the importance of each of the following during the process of digestion in human beings
a) Teeth
b) Saliva
Answer
a) Teeth
- They cut and grind food into small pieces to increase the surface area for digestion and for easy swallowing.
b) Saliva
- It contains water which is a medium for chemical reactions and acts as a solvent.
- It contains salivary amylase/ptyalin which digests starch to maltose
- They cut and grind food into small pieces to increase the surface area for digestion and for easy swallowing.
b) Saliva
- It contains water which is a medium for chemical reactions and acts as a solvent.
- It contains salivary amylase/ptyalin which digests starch to maltose
Question 4
State two ways in which active transports differs from diffusion.
Answer
- Active transport needs energy while diffusion does not need energy.
- In active transport, the movement of molecules is against the concentration gradient while in diffusion it is along the concentration gradient.
- In active transport, the movement of molecules is against the concentration gradient while in diffusion it is along the concentration gradient.
Question 5
Name two important stages of photosynthesis and state where in the chloroplasts, each takes places.
Answer
a) Light stage - grand
b) Dark stage – stroma of the chloroplasts.
b) Dark stage – stroma of the chloroplasts.