CBSE Questions for Class 10 Biology Life Processes Quiz 4 - MCQExams.com

• When the weather is hot, our body system tries to keep our body cool by evaporating the water along with unwanted things (sweating) through the skin in the form of perspiration. 
• So, skin helps the kidney by sharing its work of cleaning the body in hot weather. 
• In cold conditions, as sweating is much decreased, there is no perspiration and the kidney has to bear the entire burden of excretion and hence we urinate frequently.

• Blood pressure is defined as the pressure applied by the blood on the walls of arteries and veins during circulation. The instrument used is called a sphygmomanometer.
• the normal blood pressure of a healthy person is 120/80 mm/Hg.

• Wilting mainly occurs when the amount of water loss is more than the water absorbed from the soil.
• Plants are constantly losing water through small openings in their leaves called stomata in a process known as transpiration. Transpiration is vital for photosynthesis and helps transport nutrients from the roots to the rest of the plant. 
• The rate of transpiration depends on a number of factors, like carbon dioxide concentration, temperature, light, humidity etc. 
• Hot and dry weather increases the rate of transpiration, resulting in a loss of more water than the plant can absorb, throwing off the water balance within the plant.

$$\textbf{Correct answer: A}$$ 

$$\textbf{Option (A):}$$ 

$$\bullet$$ The transport of water and salt is mediated by the xylem vessels which are part of the vascular bundles. 

$$\bullet$$ From the roots, the water taken up inside the plant is carried to the different regions of the plant by the xylem tissue. 

$$\bullet$$ It contains dead cells which act as the tubular structure for the movement of water and minerals. 

$$\bullet$$ Using the transpiration pull, the water and minerals move upward.

$$\textbf{Option (B):}$$ 

$$\bullet$$ Sieve tubes are part of the phloem tissues which carry the nutrients. 

$$\textbf{Option (C):}$$ 

$$\bullet$$ Sclerenchyma cells are harder and stiffer structures that provide protection and support to the plants.

$$\textbf{Option (D):}$$ 

$$\bullet$$ Phloem is another vessel that is part of the vascular bundles.

$$\bullet$$ The food that is produced in the plant is carried to the different regions of the plant for the nourishment of the cells by phloem.

$$\bullet$$ The phloem mainly flows from the leaves where most of the synthesis takes place to the different regions of the plant body.

Hence, the correct answer is option (A).

• In the case of kidney failure, an artificial kidney can be used. 
• An artificial kidney is a device to remove nitrogenous waste products from the blood through dialysis. 
• Dialysis is the artificial process of eliminating waste (by diffusion) and unwanted water (by ultrafiltration) from the blood.

• The human circulatory system consists of a muscular chambered heart, a network of closed branching blood vessels and blood, the fluid which is circulated. 
• It is essentially a network of tubes that supplies to all living cells essential nutrients, O$$_2$$ and other essential substances. 
• Also, the waste or harmful substances produced are removed continuously for the healthy functioning of tissues.