The kidneys in human beings are a part of the system for _________________

• Nutrition

• Respiration

• Excretion

• Transportation

The breakdown of pyruvate to give CO₂, water, and energy takes place in ___________

• Cytoplasm

• Mitochondria

• Chloroplast

• Nucleus

If Salivary amylase is lacking in the saliva, which of the the following events in the mouth will be affected?

• Proteins breakdown into amino acid

• Starch breaking down to sugars

• Fats breaking down to fatty acids and glycerol

• Absorption of vitamins

The inner lining of the stomach is protected from the action of Hydrochloric acid by ____________

• Pepsin

• Salivary amylase

• Bile

• Mucus

During respiration exchange of gases takes place in _________________

• Trachea

• Alveoli

• Larynx

• Bronchii

What prevents the backflow of blood inside the heart during contraction?

• Valves in the heart

• Thin walls of the Atria

• Thick walls of Ventricles

• Septum

The blood leaving the tissues becomes richer in _______________

• Water

• Carbon dioxide

• Oxygen

• Haemoglobin

During the vigorous muscular activity, which of the following type of respiration occurs?

• Anaerobic

• Aerobic

• Both of these

• None of these

Which blood vessel has no muscles in its walls?

• Artery

• Veins

• Capillaries

• Vena Cava

Blood cells which help in clotting at the site of injury ________________

• RBC's

• WBC's

• Plastids

• All the above