Excretion questions | form three Biology

Which of the following is not a waste product in man?

• Feces
• Uric acid
• Sweat
• Carbon dioxide
• Urea

Draw a well labeled internal structure of the human kidney

Study the following list of substances :

Water , Urea, Glucose, Calcium , Potasium, Sodium.

Which of the substances above will be excreted by a mammal in a greater amount under the folllowing conditions ?

• Consumption of high amount of protein
• Insufficient secretion of antideuretic hormone
• Insufficient secretion of insulin

Give reasons to support your answer for the above quaetions.

Draw a well labeled diagram of a mammalian kidney showing the internal structure.

Name the organ which

1. produce urea
2. excretes urea

Mention two functions of the skin.

Distinguish between excretion and osmoregulation.

Study the diagram below (Figure 3) which shows a part of the human uriniferous tubule then answer the questions that follow.

1. (i) Name the parts labelled A, B, C and D.
   (ii) What IS the name given to the fluid labelled C?
   (iii) Name two (2) components of blood that will not diffuse into the part labelled C.
   (iv) Name a nitrogenous waste which is present in urine but absent in the part labelled B.
2. List the processes involved in urine formation.

Urine is a waste product of metabolism , which is very important physiological process taking place in the human body. Discuss the mechanism of urine formation.

Useful substances are retained in the kidney by
A Filtration
B Osmosis
C Selective reabsorption
D Osmo-regulation
E Diffusion