Describe the transmission and prevention of malaria. Also, explain the role of reducing sugars in germinating seeds and the economic uses of bacteria.

Place equal amounts of extract A into test tube 1 and extract B into test tube 2. Add an equal volume of Benedict's solution to both test tubes.

Heat both test tubes in a boiling water bath for 5-10 minutes.

Observation: Test tube 1 (germinating seeds) will show a color change from blue to green, yellow, orange, or brick-red precipitate, indicating the presence of reducing sugars. Test tube 2 (non-germinating seeds) will remain blue, indicating the absence of reducing sugars.
Conclusion: Reducing sugars are formed in germinating bean seeds, demonstrating the breakdown of stored food reserves.

c) Bacteria are economically useful in several ways:

• Food Production: Used in the fermentation of foods like yogurt, cheese, and vinegar.
• Medicine: Used to produce antibiotics, vaccines, and insulin through genetic engineering.
• Agriculture: Nitrogen-fixing bacteria (e.g., Rhizobium) enhance soil fertility by converting atmospheric nitrogen into usable forms for plants.
• Bioremediation: Used to clean up environmental pollutants such as oil spills.
• Industrial Applications: Produce various chemicals, enzymes, and vitamins.

a)

• (i) Stimulus: An external or internal change in the environment that is detected by a receptor and causes a response in an organism.
• (ii) Reflex action: An involuntary, rapid, and automatic response to a stimulus that does not involve conscious thought, mediated by a reflex arc.
• (iii) Phototropism: The growth movement of a plant in response to light, typically growing towards a light source.

b) When the skin touches a hot object:

1. Thermoreceptors (heat receptors) in the skin are stimulated, generating nerve impulses.
2. These impulses travel along sensory neurons to the spinal cord.
3. In the spinal cord, the sensory neuron synapses with a relay neuron, which then synapses with a motor neuron.