1. a) Name the male sex hormone.
b) How does scrotum help in the development of sperms?
2. How does AIDS spread? Give any two ways.
3. A force of 100 N is applied on an object of area 4 m2 . Calculate the pressure.
4. Give reasons:
a) Grooves are made in tyres.
b) The bodies of birds are streamlined.
Answers
Explanation:
1.
ᴀ)Testosterone is the main sex hormone found in men.
ʙ)For normal sperm development, the testes must be at a temperature slightly cooler than the body temperature. Special muscles in the wall of the scrotum allow it to contract (tighten) and relax, moving the testicles closer to the body for warmth and protection or farther away from the body to cool the temperature.
2.Contact between broken skin, wounds, or mucous membranes and HIV-infected blood or blood-contaminated body fluids. Deep, open-mouth kissing if both partners have sores or bleeding gums and blood from the HIV-positive partner gets into the bloodstream of the HIV-negative partner.
3.Pressure exerted by a force on a object of Area is given by, Therefore, A force of 100N is applied to an object of area 4ᴍ² square. The pressure is 25Pa.
Answer:
1.a) Penis is male sex hormone.
b)Aids spread through:-
1) Kisses and 2) Having intercourse.