CBSE Questions for Class 10 Biology Life Processes Quiz 9 - MCQExams.com

• Photosynthesis is the process of preparing food in the presence of sunlight and chlorophyll. 
• In this process, the plant uses water from the soil, carbon dioxide from the air.

• It occurs in green plants, certain algae, blue-green algae and bacteria.
  
• During this process, carbon dioxide is reduced into glucose while water is oxidized as it is split to release electrons, protons and atomic oxygen.

$$\textbf{Correct answer: B}$$ 

$$\textbf{Option (A):}$$ 

$$\bullet$$ The absorption of water is one of the chief functions of the large intestine. 

$$\textbf{Option (B):}$$ 

$$\bullet$$ Absorption of nutrients occurs in the small intestine.

$$\bullet$$ The nutrients are absorbed through the villi of the small intestine. 

$$\textbf{Option (C):}$$ 

$$\bullet$$ There are mucus-secreting cells in the large intestine which lubricate the undigested food that comes from the small intestine to form the faeces. 

$$\bullet$$ This also facilitates the easy movement of faeces through the large intestine. 

$$\textbf{Option (D):}$$ 

$$\bullet$$ The feces is temporarily stored in the rectum and with the voluntary reflex in the adults, it is removed through the anus.

Hence, the correct answer is option (B).

1. Blood pressure (BP) is the pressure of circulating blood on the walls of blood vessels.
   
2. In arteries near to heart is larger than the distant ones as pushing by heart decreases.
3.  It is lower in the capillaries than in the arteries because the velocity of flow is increased with the decrease in diameter and vice versa.
   
4. . It is usually lower in women than in men as men have more hypertension than women.
   

The veins (except pulmonary veins) carry deoxygenated blood from the tissues back to the heart. The blood flows in the veins at very low pressure. This flow of blood at low pressure increases the possibility of the blood flowing backwards. The presence of valves in the veins prevents the blood flowing at low pressure from flowing backwards.

Thus, the correct answer is 'Low pressure.'

• Saliva is a thick, colourless and glistening liquid with about 98 percent water in our mouth. The saliva contains chemicals like mucus, salts, antibacterial substances, and enzymes that help in the digestion of food especially starch.
• The digestion of starch into sugar is done in the mouth because of an enzyme, salivary amylase that the saliva contains.
• Saliva also helps to make the food into a bolus structure. For the ease of transport into the stomach.

• Hemodialysis is used for people with a critical kidney disorder and uraemia. 
• Kidney/renal failure may occur from a physical injury or a disease like diabetes, high blood pressure, or other disorders.
• An elevated level of urea and other nitrogenous waste compounds in the blood is characteristic of uremia.
• In any of the conditions where the kidneys are not functioning properly, waste starts accumulating in the blood. This results in coma and even death.
• To cure this, the patient is subjected to dialysis. Dialysis maintains the body balance in the following ways:

1. It controls blood pressure.
2. It removes excess water and metabolic wastes from the body.
3. Prevents chemicals such as potassium, bicarbonate and sodium from reaching hazardous levels.

• This treatment may continue for months or years since most kidney failures are irreversible.

• Our heart has four chambers, two relatively small thin-walled upper chambers called atria. These receive oxygenated blood (left atrium) and deoxygenated blood (right atrium). These are the 'receiving chambers'.
• The atria pour the blood received by them into the respective ventricle. Ventricles are thick-walled as they have to pump blood. The right ventricle pumps blood into the pulmonary artery while the left ventricle pumps blood into the aorta.