Class 10 Science Chapter 5 MCQ

Heterotrophs are those organisms which cannot make their own food from inorganic substances like CO2 and water as they do not have chlorophyll to trap solar energy, e.g., all animals, most bacteria and fungi. They depend on other organisms for their food. Autotrophs synthesize their own food through photosynthesis by utilising solar energy. e.g., green plants.

The first step is the break-down of glucose, a six-carbon molecule, into a three-carbon molecule called pyruvate. This process takes place in the cytoplasm.

Starch breaking down into sugars and later on in Stomach it further break down in glucose.

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.

Fermentation is a form of anaerobic respiration. Pyruvate can be converted into ethanol and CO, in yeast during fermentation. Since this process takes place in the absence of air (oxygen), it is called anaerobic respiration. It takes place in cytoplasm. Break down of pyruvate using oxygen, i.e., aerobic respiration takes place in the mitochondria.

Using the material in the form of carbon dioxide and water which is converted into carbohydrates in the presence of sunlight and chlorophyll. Carbohydrates are utilised for providing energy to the plant. The carbohydrates which are not used immediately are stored in the form of starch, which serves as the internal energy reserve to be used as and when required by the plant.

The digestion in stomach is taken care of by the gastric glands present in the wall of the stomach. These release hydrochloric acid, a protein digesting enzyme called pepsin and mucus. The mucus protects the inner lining of the stomach from the action of the acid under normal conditions.

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

Organisms which can make their own food from carbon dioxide and water are called autotrophs. Carbon dioxide and water are inorganic substance. So, we can say that, those organisms which can make their own food from the inorganic substances present in the environment are called autotrophs. All the green plants are autotrophs.

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

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.

Nostrils → pharynx → larynx → trachea → alveoli. The alveoli provide a surface where the exchange of gases can take place.

Alveoli of lungs. The walls of the alveoli contain an extensive network of blood-vessels. When we breathe in, we lift our ribs and flatten our diaphragm, and the chest cavity becomes larger as a result. Because of this, air is sucked into the lungs and fills the expanded alveoli. The blood brings carbon dioxide from the rest of the body for release into the alveoli, and the oxygen in the alveolar air is taken up by blood in the alveolar blood vessels to be transported to all the cells in the body.

Nephrons are the filtration units of kidneys. It is the structural and functional unit of a kidney and has three functions – filtration, reabsorption and secretion. Urine from the kidney passes through a tube called ureter, that carry urine into the urinary bladder. The urethra is a canal that carries urine from bladder and expels it out of body. Neurons nerve cells and are functional units of nervous system.

Small intestine receives bile from the liver which is normally stored in the gall bladder. It performs two functions i.e. makes the food alkaline and break the fats present in food into small globules by the process of emulsification.

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.

Arteries are the vessels which carry blood away from the heart to various organs of the body. Since the blood emerges from the heart under high pressure, the arteries have thick, elastic walls. Veins collect the blood from different organs and bring it back to the heart. They do not thick walls because the blood is no longer under pressure, instead they have valves that ensure that the blood flows in only one direction.

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].

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

Nitrogen is an essential element used in the synthesis of proteins and other compounds. This is taken up in the form of inorganic nitrates or nitrites.

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

Aerobic respiration uses oxygen for respiration. It takes place in the mitochondria. After glycolysis, pyruvate (from cytoplasm) enters the mitochondria and is oxidised in a series of reactions, to form considerable amount of energy (ATP), CO2 and H2O.

Generally, the normal blood pressure values are: Systolic pressure: 120 mm Hg Diastolic pressure: 80 mm Hg This is usually written as 120 by 80.

The blue black colour of rice water confirms the presence of starch. No colour change will be seen in case of proteins fats in iodine solution colour, when iodine is added with them. Note: A starch solution on addition of iodine turns blue black in colour.