The Human Body - Free MCQ Practice Test with solutions, Class 6 Year 6

The circulatory system’s primary role is to transport nutrients, oxygen, and remove waste products like carbon dioxide, as described in the text. Options A, C, and D are incorrect as they refer to functions of other systems or are not the primary role.

The right side of the heart pumps oxygen-poor blood to the lungs for oxygenation, while the left side pumps oxygen-rich blood to the body. Thus, option B is correct, and the others are inaccurate.

Capillaries connect arteries and veins and have thin walls to allow the exchange of substances like oxygen and nutrients, as per the text. The other options describe functions of arteries, veins, or the heart, so A is correct.

Mucus in the respiratory system traps germs in the nose and air passages, helping prevent infections, as noted in the body’s defenses section. The other options do not directly trap germs, so A is correct.

The ovaries produce ova (egg cells) in the female reproductive system. The uterus, oviducts, and birth canal have different roles, so C is the correct answer.

Fertilisation is the process where a sperm cell joins an egg cell to form a new organism, as explained in the reproductive system section. The other options refer to different processes, so A is correct.

The skin acts as a barrier to prevent germs from entering the body, as described in the body’s defenses section. The other options refer to different defense mechanisms, so D is correct.

Ibn al-Nafis discovered that blood moves from the right side of the heart to the lungs and back to the left side, as noted in the historical discoveries section. The other scientists contributed differently, making C correct.

Marcello Malpighi observed capillaries under a microscope, confirming their role in connecting arteries and veins, as per the historical section. The other options are unrelated to his discovery, so A is correct.

Sleeping under bed nets prevents mosquito bites, which transmit diseases like malaria, as explained in the disease prevention section. The other options address different disease transmission methods, making B correct.