Class 10 Science Chapter 5 MCQ

It is incorrect as; autotrophs can convert carbon dioxide and water into carbohydrates only in the presence of sunlight. The autotrophs contain the green pigment called chlorophyll which is capable of trapping sun energy. This trapped energy is utilised by them to make food by combining inorganic materials like CO2 and H2O by the process of photosynthesis. The food that is not used immediately, is stored in the form of starch. These autotrophs constitute the first trophic level in food chains.

Yeast, mushroom, bread mould are saprophytes who break down the food materials outside the body then absorb it.

Non-living things which are not alive cannot move by themselves. For example, a stone is a non-living thing which cannot move by itself from one place to another or show any other type of movement. We will have to move it by applying force from outside.

Here, all the statements are correct. Hence your answer will be option [D].

Energy is required by an organism even during sleep because when we are asleep a number of biological processes keep on occurring in the body which require energy. Our heart beats non-stop even when we are asleep to pump blood throughout the body. And this beating of heart requires energy. Thus, the working of heart requires are continuous supply of energy.

The solution turned blue-black in colour just because of starch.

The digestion of food completed in Small intestine. In large intestine only absorption of water take place. In mouth cavity the digestion starts only. In stomach, the digestion of proteins start in acidic medium with the help of pepsin.

Large number of tiny pores called stomata are present on the surface of the leaves of plants. The gaseous exchange as well as transpiration takes place through these pores. The opening and closing of the pore is a function of the guard cells. The guard cells swell when water flows into them, causing the stomatal pores to open. Similarly, the pore closes if the guard cells shrink or losses water in them.

Carbon dioxide is used in photosynthesis for the products on of food. The oxidation of carbon compounds occurs in respiration.

The summary equation of photosynthesis is: 6CO2 + 12H20+ Chlorophyll +Sunlight → C6H12O6 +6CO2 + 6H2O by using. Photosynthesis is a process by which green plants make their own food, e.g., glucose, CO2 and H2O in the presence of sunlight energy and chlorophyll in the presence of. Oxygen gas is released during the process of photosynthesis.

Lime water turns milky due to presence of carbon dioxide. The reaction of lime water and carbon dioxide forms calcium carbonate which is insoluble in water and makes lime water milky.

In autotrophs, the cellular energy reserve is starch. However, carbohydrates serve as a major fuel in the cells to provide energy for life processes. The sugar (glucose) produced that is not used immediately gets stored in the form of starch in plants. In animals, food is stored in the form of glycogen. These food reserves provide energy as and when required by the organisms.

Chloroplast are the organelles in the cells of green plants which contain chlorophyll and where photosynthesis take place. Thus, photosynthesis occurs in the organelles called the chloroplast present in the photosynthetic cell or mesophyll cell of green plants. In the other words, the site of photosynthesis in cell of the leaf are chloroplast. Chloroplast can be seen easily by using a light microscope.

The blood leaving the tissues becomes richer in CO2. The main artery (aorta) carries oxygenated blood to all the organs of the body from the heart. When the oxygenated blood passes through the capillaries of the body organs/tissues, it gives oxygen to the body cells. At the same time, carbon dioxide produced during respiration enters into blood. Thus, deoxygenated blood (carrying CO2) leaves the tissues and enters the vena cava, from where they are again passed to the lungs for oxygenation.

The oesophagus carries food to the stomach. When the slightly digested food enters the food pipe, the walls of food pipe start contraction and expansion movements. The contraction and expansion movement of the walls of food pipe is called peristaltic movement. This peristaltic movement of food pipe pushes the slightly digested food into the stomach.

During the photosynthesis, the following steps take place: (i) Absorption of light energy by chlorophyll. (ii) Conversion of light energy to chemical energy and splitting of water molecules into hydrogen and oxygen. (iii) Reduction of carbon dioxide to carbohydrates.

In Pisces (fishes), the heart is 2 chambered oral pumps deoxygenated blood to the gills, where oxygenation takes place by diffusion. The oxygenated blood from the gills is supplied to the body parts where oxygen is utilised and CO2 enters it making the blood deoxygenated. This deoxygenated blood returns to the heart. Thus, it has single circulation, i.e., blood passes through the heart only once during one complete cycle.

Non-living things which are not alive cannot move by themselves. For example, a stone is a non-living thing which cannot move by itself from one place to another or show any other type of movement. We will have to move it by applying force from outside.

It is in the alveoli in the lungs where gaseous exchange takes place. The walls of the alveoli are very thin and surrounded by network of very thin blood capillaries. The presence of millions of alveoli in the lungs provides a large area for the exchange of gases.

The whole process of an aerobic respiration take place in the cytoplasm of cells.

When we eat something a fluid called saliva secreted by the salivary glands. The saliva contains an enzyme called salivary amylase that breaks down starch which is a complex molecule to give simple sugar.

Fermentation is a form of anaerobic respiration in which Pyruvate can be converted into ethanol and carbon dioxide by yeast.

Mitochondria are the sites of aerobic respiration in the cells. The breakdown of pyruvate to give carbon dioxide, water and energy takes place in mitochondria.

Here, all the statements are correct. Hence your answer will be option [D].

Carbon dioxide gas turns limewater milky. When air is blown from mouth into test, the lime water turns milky because the air we breathe out has more CO2.