The diagrams below illustrate parasites of farm animals Study them and answer the questions that follow. a) Identify the parasites labelled I and II. b) Men...

Answer Details

a) The parasite labelled I is a tick, while the parasite labelled II is a liver fluke.

b) Three external features of the tick (parasite I) are its hard, flattened body covered in a tough, chitinous exoskeleton, eight legs, and a mouthpart structure called a hypostome used for anchoring and feeding.

c) The liver fluke (parasite II) is found in the liver of the host animal.

(i) Four adaptive features of the liver fluke on its host are:

- A flat body shape that allows it to move easily through narrow spaces in the liver.

- Hooks and suckers on its body that help it attach to the liver tissue.

- The ability to secrete chemicals that prevent the host's immune system from attacking it.

- The production of eggs that are passed out of the host's body in the feces, allowing the parasite to continue its life cycle.

(ii) Two intermediate hosts of the liver fluke are snails and ants.

d) Three effects of the tick (parasite I) on its host are:

- The transmission of diseases such as Lyme disease and tick-borne fever.

- Irritation and itching at the site of the tick bite.

- Anemia, or a decrease in the number of red blood cells, due to the tick's blood-feeding behavior.

e) Three effects of the liver fluke (parasite II) on its host are:

- Liver damage, including inflammation, scarring, and tissue death.

- Reduced growth and productivity in farm animals due to decreased feed intake and weight gain.

- Increased susceptibility to other diseases due to the weakening of the immune system by the liver fluke's presence. Liver flukes are responsible for significant economic losses in the livestock industry, and can also infect humans who consume contaminated food or water.