CBSE Questions for Class 10 Biology Life Processes Quiz 6 - MCQExams.com

$$\textbf{Correct answer: D}$$ 

$$\textbf{Option (A):}$$ 

$$\bullet$$ Digestion occurs in all the parts of the digestive system starting from the mouth. 

$$\bullet$$ There are digestive enzymes secreted in the mouth, stomach and small intestine for breaking down the macromolecules into smaller particles. 

$$\textbf{Option (B):}$$ 

$$\bullet$$ Elimination of undigested food or egestion occurs through the anus.

$$\bullet$$ The removal of this food takes place as these food molecules are not absorbed or digested by the system. 

$$\textbf{Option (C):}$$ 

$$\bullet$$ Degradation occurs in the presence of enzymes.

$$\bullet$$ Enzymes break down the larger food molecules into smaller forms that can enter the system directly. 

$$\textbf{Option (D):}$$ 

$$\bullet$$ About two-thirds of the length of the alimentary canal forms the small intestine. The intestinal lining contains villi which increase the surface area of the small intestine. 

$$\bullet$$ Most of the digested food is absorbed in the small intestine which moves to the blood and lymph vessels. 

Hence, the correct answer is option (D).

• Autotrophs are organisms that can produce their own food using light energy through photosynthesis or by using chemical energy through the process of chemosynthesis. 
• Heterotrophs cannot synthesize their own food and are dependent on autotrophs for nutrition. 

• Plasma is the largest component of your blood, making up about 55 per cent of its overall content. 
• When isolated on its own, blood plasma is a light yellow liquid, similar to the colour of straw. Along with water, plasma carries salts and enzymes.

During respiration, glucose is converted into carbon dioxide and water in the presence of oxygen within a living cell. The energy is released in the form of ATP or adenosine triphosphate. So, we can say that the energy stored in glucose is transferred into ATP. This process can be shown in the form of a word equation as shown below:

Glucose + oxygen ----> carbon dioxide + water + energy

So, the correct answer is option C.

• Sweat is excreted through sweat glands. It helps the body to maintain a cool, consistent temperature, which also helps to maintain homeostasis. 
• Sweating is not part of blood circulation, water circulation, and respiration. 
• It helps the body to get rid of the excess of salt and water in the body.

• One of the major organs of the excretory system is the kidneys. 
• The kidneys are complex organs that play an important role in the production, storage, and release of liquid waste. 
• Gills in fish are part of their excretory system which excretes ammonia. 
• The lungs in the respiratory system excrete some waste products, such as carbon dioxide and water. 
• The skin is another excretory organ that removes the body's wastes through sweat.

• In the body, the heart is a muscular organ made up of cardiac muscles, which have four chambers. 
• The right side of the heart receives deoxygenated blood from the veins and pumps it to the lungs that oxygenate it.
• The left side of the heart receives oxygenated blood from the lungs and pumps it through the arteries to the whole body. 

$$\textbf{Correct Option A}$$

$$\textbf{Solution}$$

$$\bullet$$ $$\textbf{Option A}$$ Every organ in our body needs the involvement of circulating fluid. Ex - The digestive system digests & absorb nutrients which are needed to be transported to every cell in the body.

$$\bullet$$ $$\textbf{Option B}$$  The function of the respiratory system is to move two gases: oxygen and carbon dioxide. Gas exchange takes place in the millions of alveoli in the lungs and the capillaries that envelop them.

 $$\bullet$$ $$\textbf{Option C}$$  Excretion is a process in which metabolic waste is eliminated from an organism. In vertebrates this is primarily carried out by the lungs, kidneys, and skin.

 $$\bullet$$ $$\textbf{Option D}$$ This is not the correct option.

So, the correct option is A. 

$$\textbf{Correct Option B}$$

$$\textbf{Solution}$$

$$\bullet$$ $$\textbf{Option A}$$ Option A. Digestion is the process in which the large food molecules are synthesized into water soluble small food molecules so that it can easily be absorbed by our body into the bloodstream.

$$\bullet$$ $$\textbf{Option B}$$ Respiration is the process in which the oxygen molecules helps in the synthesis of sugar which results in the release of energy. This energy is required to carry out all the our body.

$$\bullet$$ $$\textbf{Option C}$$ Regulation is the mechanism in which the body regulate its temperature and maintains stable equilibrium.

$$\bullet$$ $$\textbf{Option D}$$ Reproduction is the process in which in new offspring is produced from its parents. Organisms exist on the basis of reproduction.

So, the correct option is B. 

• Plants have tissues such as the xylem and phloem to transport water, nutrients, and minerals. Xylem transports water and other mineral salts, while phloem transports sucrose and amino acids between leaves and other parts of the plant body.
• Plants utilize the sugars produced during photosynthesis to produce energy for plant growth. This energy production takes place in the mitochondria of the cells. And the process is known as respiration in plants.
• Waste products such as H$$_2$$O, and O$$_2$$ are excreted through stomata and lenticels. Plants also store wastes in the form of resins and gums. Many plants also release waste products into the surrounding soil.
• Hence, all the above processes are essential for maintainance of the plant body. 

• Excretion is the process of removal of waste from the body.
• Respiration is the breakdown of complex food to release energy.
• Photosynthesis is the synthesis of food from inorganic materials like water, carbon dioxide and sunlight.
• All of these are life processes performed only by living organisms and help to maintain their metabolic function.

Pancreatic amylase, trypsin and lipase along with intestinal peptidases and maltase carry out the chemical digestion of food in the small intestine. The simpler substances formed by chemical digestion are then absorbed by the intestinal villi in the small intestine. Digestion of food takes place in the mouth and stomach but absorption does not happen here. No digestion of food takes place in the oesophagus and the large intestine.

• Thus, the correct answer is option A.