Biology(Excretory system)

Question 1

What is excretion?

Answer 1

The process of getting rid of waste materials

Question 2

What are some waste materials that are excreted?

Answer 2

1. Carbon dioxide, made by the body cells in respiration
   2.urea, waste substance made by the liver cells
2. excess water that is not needed by the body

Question 3

Describe the process of excreting urea

Answer 3

When we eat food. proteins in the food are broken down into smaller molecules in the digestive system. These molecules go into the blood. The blood transports it to the liver.

If the protein is more than we need, it is turned into urea by the liver. Urea us a poisonous substance. If it builds up, it causes a person to get ill.

As soon as the liver turns the small molecules into urea, it is taken away by from the liver in the blood. The urea is removed from the blood by the kidneys

Question 4

What is the solution made of urea dissolved in water?

Answer 4

urine

Question 5

If the kidney fails what happens?

Answer 5

Excess urea will build up which cause a person to become ill

Question 6

Describe the process of the kidney removing excess water?

Answer 6

The urine made in each kidney flows down a long tube called the ureter. This carries it to the bladder, which can store it for a while. The urine can flow out the bladder to the outside world through another tube called the urethra

Question 7

What are the organs involved in excretion?

Answer 7

Liver, Kidney, ureter, bladder, urethra