A) i) List two (2) types of animal parasites. ii) State three (3) economic importance of the grasshopper. b) i) State the law of floatation. ii) Explain how a submarine operates. c) i) State three (3)

here are the answers to question 5.

5. a) i) List two (2) types of animal parasites.

• • Endoparasites (e.g., tapeworms, roundworms)
• • Ectoparasites (e.g., ticks, fleas)

ii) State three (3) economic importance of the grasshopper.

• • Crop damage: Grasshoppers can cause significant destruction to agricultural crops, leading to reduced yields and economic losses for farmers.
• • Food source: In some cultures, grasshoppers are consumed as a protein-rich food source, contributing to local economies.
• • Pest control costs: The need for pesticides and other control measures to manage grasshopper infestations incurs substantial economic costs.

b) i) State the law of floatation.
The law of floatation states that an object floats if the buoyant force acting on it is equal to the weight of the fluid it displaces, and this buoyant force is equal to the object's total weight.

ii) Explain how a submarine operates.
A submarine operates by changing its overall density. It has ballast tanks that can be filled with water to increase its density, causing it to sink. To rise, water is expelled from the ballast tanks and replaced with compressed air, which decreases its density, allowing it to float upwards.

c) i) State three (3) ways of preventing dental decay.

• • Brushing teeth regularly (at least twice a day) with fluoride toothpaste.
• • Flossing daily to remove food particles and plaque between teeth.
• • Limiting the intake of sugary foods and drinks.

ii) State one (1) cause each of:
α) Constipation

• Lack of dietary fiber is a common cause of constipation.

β) Indigestion

• Eating too quickly or consuming fatty, spicy, or acidic foods can cause indigestion.

d) i) What is an alloy?
An alloy is a mixture of two or more elements, at least one of which is a metal, combined to create a new substance with properties different from its constituent elements.

ii) Name the main elements present in each of the following:
α) Bronze

• Copper and Tin

β) Nichrome

• Nickel and Chromium

γ) Duralumin

• Aluminum, Copper, Magnesium, and Manganese