Summative Practice 11 – Question 5 & 6 (Form 4 Biology Textbook Exercise and Answer)

Question 5:Two individuals acquired immunity against chickenpox in different situations. Individual X recovered from chickenpox. Individual Y was injected with a type of suspension and received immunity against chickenpox after a few months.Explain the immunity acquired by(a) individual X(b) individual Y Answer:(a) In individual X, lymphocytes are stimulated to produce antibodies that destroy antigens. Memory … Read more

Summative Practice 11 – Question 4 (Form 4 Biology Textbook Exercise and Answer)

Question 4:Figure 1 illustrates the changes in the antibody levels in the blood of individuals X and Y for a specific period of time.(a)(i) What type of immunity did individuals X and Y acquire?(ii) State the substance injected in individuals X and Y.(iii) Explain the differences in the content of the substances you mentioned in … Read more

Summative Practice 11 – Question 1 – 3 (Form 4 Biology Textbook Exercise and Answer)

Question 1:Suggest an immediate treatment to an individual bitten by a very poisonous snake. Answer:The individual must be given a serum injection containing antibodies that can fight the toxin found in the snake venom. Question 2:Explain how a mother who has HIV can infect a foetus in her womb. Answer:Through the mother’s placenta to the … Read more

Formative Practice 11.3 (Form 4 Biology Textbook Exercise and Answer)

Question 1:What is the meaning of AIDS? Answer:AIDS is Acquired Immunodeficiency Syndrome. Question 2:Explain how HIV infection can cause someone to suffer from AIDS. Answer:The HIV virus attacks and disables the immune system of the individual infected by the virus. The HIV virus attacks and destroys lymphocytes that function to destroy pathogenic microorganisms.This may result … Read more

Formative Practice 11.2 (Form 4 Biology Textbook Exercise and Answer)

Question 1:What are the types of immunity that decrease according to time? Explain why. Answer:Artificial passive immunity. The body does not produce its own antibody; therefore, the immunity does not last long and only provides a temporary protection. Question 2:Propose immediate treatment that can be given to someone who has been bitten by a poisonous … Read more

Formative Practice 11.1 (Form 4 Biology Textbook Exercise and Answer)

Question 1:What is the meaning of immunity? Answer:Immunity is the body’s ability to fight against disease infections caused by pathogens or foreign substances, by specifically fighting the particular pathogen. Question 2:Name two characteristics of the skin that allows the skin to react as an effective first line of defence. Answer:The skin is a physical defence … Read more