Question

What is the main function of the excretory system?
A. To collect and remove waste from the body
B. To strengthen skeletal muscles
C. To protect the nervous system
D. To bring oxygen to body cells

Answer 1

Hint: The physiological process of eliminating metabolic waste from the body is known as excretion. Amino acids, urea, uric acid, carbon dioxide, water, and ammonia are among the excretory products.
Amino acids are excreted by some Molluscs and Echinoderms as waste products from the body. Ammonia is the principal excretory product in mammals, and it is made up of proteins found in our meals. It is the most poisonous nitrogenous waste, and most amphibians and aquatic creatures excrete it through diffusion.
Urea is the nitrogenous waste excreted by mammals. It is less poisonous and has a lower water solubility. Uric acid is excreted by birds and reptiles as nitrogenous waste.

Complete answer:
Option A: The kidneys have many functions, but the most important is to remove waste from the blood and produce urine (pee). When a person pees, the urinary system removes this waste from the body.
So, option A is correct.
Option B: Strength training is the best sort of exercise for building muscle, while cardiovascular activity can also help.
So, option B is not correct.
Option C: Nerves branch out all across the body along the route. Bone protects both the brain and the spinal cord: the brain is protected by the skull bones, and the spinal cord is protected by a group of ring-shaped bones called vertebrae. Layers of membranes called meninges and a unique fluid called cerebrospinal fluid cushion them both.
So, option C is not correct.
Option D: The lungs and respiratory system allow oxygen from the air to enter the body while also allowing carbon dioxide from the air to leave the body.
So, option D is not correct.

So, the correct answer is “Option A”.

Note:
Organs of the human excretory system aid in the elimination of nitrogenous wastes from the body.
The kidney, ureter, urinary bladder, and urethra are the primary excretory organs.
The blood is filtered by the kidneys, and the filtrate recovered is urine.
Urine travels from the ureter to the urinary bladder before being evacuated from the body. Micturition is the term for this.