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Which one of the following changes may occur due to desertification? (a) Increased chances of floods. (b) Conversion of fertile land into a desert. (c) The decrease in atmospheric temperature. (d) Increase in water holding capacity of the soil.

d) Conversion of fertile land into a desert Desertification is a type of land degradation in which a relatively dry land region becomes... View Article

Which of the following equations is the summary of photosynthesis? (a) 6CO2 + 12H2O → C6H12O6 + 6O2 + 6H2O (b) 6CO2 +H2O + Sunlight→C6H12O6 + O2 + 6H2O (c) 6CO2 + 12H2O + Chlorophyll + Sunlight→ C6H12O6 + 6O2 + 6H2O (d) 6CO2 + 12H2O + Chlorophyll + Sunlight→ C6H12O6 + 6CO2 + 6H2O

(c) 6CO2 + 12H2O + Chlorophyll + Sunlight → C6H12O6 + 6O2 + 6H2O Photosynthesis is a process by which plants and photosynthetic bacteria... View Article

Which is the correct sequence of the components of a reflex arc? (a) Receptors→ Muscles→ Sensory neuron→ Motor neuron→ Spinal cord (b) Receptors→ Motor neuron → Spinal cord → Sensory neuron → Muscle (c) Receptors → Spinal cord → Sensory neuron → Motor neuron → Muscle (d) Receptors → Sensory neuron → Spinal cord → Motor neuron → Muscle

d) Receptors → sensory neuron → spinal cord → motor neuron → muscle When a receptor is stimulated, it sends a signal to the... View Article

In brief state what happens when (a) dry apricots are left for sometime in pure water and later transferred to sugar solution? (b) a Red Blood Cell is kept in concentrated saline solution? (c) the Plasma membrane of a cell breaks down? (d) rheo leaves are boiled in water first and then a drop of sugar syrup is put on it? (e) golgi apparatus is removed from the cell?

a) Dry apricots when left in pure water, will gain water due to endosmosis and swell. When placed in a concentrated sugar solution, they lose... View Article

Cattle husbandry is done for the following purposes (i) Milk Production (ii) Agricultural work (iii) Meat production (iv) Egg production (a) (i), (ii) and (iii) (b) (ii), (iii) and (iv) (c) (iii) and (iv) (d) (i) and (iv)

a) (i), (ii) and (iii) Cattle husbandry is defined as the management of cattle by humans for monetary gains, yielding good quality and... View Article

Identify the correct statement. (a) Tissue is a group of dissimilar cells. (b) An organ consists of similar cells. (c) Vacuoles are not found in plant cells. (d) Prokaryotes do not have a nucleus.

(d) Prokaryotes do not have a nucleus. Prokaryotes do have their genomic DNA concentrated and localized to a small area within the cell (nucleoid... View Article

Metals generally react with dilute acids to produce hydrogen gas. Which one of the following metals does not react with dilute hydrochloric acid? (a) Magnesium (b) Aluminium (c) Iron (d) Copper

Copper Less reactive metals such as silver, copper, gold etc don't react with dilute hydrochloric acid. So, these metals do not produce hydrogen... View Article

Single circulation i.e., blood flows through the heart only once during one cycle of passage through the body, is exhibited by (a) Labeo, Chameleon, Salamander (b) Hippocampus, Exocoetus, Anabas (c) Hyla, Rana, Draco (d) Whale, Dolphin, Turtle

b)Hippocampus, Exocoetus, Anabas The circulatory system consists of a network of blood vessels that supply the body, oxygen and nutrients and... View Article

Choose the correct statement that describes arteries. (a) They have thick elastic walls, blood flows under high pressure; collect blood from different organs and bring it back to the heart (b) They have thin walls with valves inside, blood flows under low pressure and carry blood away from the heart to various organs of the body (c) They have thick elastic walls, blood flows under low pressure; carry blood from the heart to various organs of the body (d) They have thick elastic walls without valves inside, blood flows under high pressure and carry blood away from the heart to different parts of the body.

d) They have thick elastic walls without valves inside, blood flows under high pressure and carries blood away from the heart to different parts... View Article

Sets of reproductive terms are given below. Choose the set that has an incorrect combination. (a) sperm, testis, sperm duct, penis (b) menstruation, egg, oviduct, uterus (c) sperm, oviduct, egg, uterus (d) ovulation, egg, oviduct, uterus

c) Sperm → oviduct, egg → uterus Reproduction is the process by which organisms make more organisms like themselves. Millions of sperm are in... View Article

In the list of animals given below, the hen is the odd one out. (human beings, cow, dog, hen). The reason for this is (a) it undergoes internal fertilisation. (b) it is oviparous. (c) it is viviparous. (d) it undergoes external fertilisation.

(b) It is oviparous The hen is the odd one out because it is oviparous, i.e. it lays an egg from which young ones are hatched later on.... View Article

Which of the following is an incorrect statement? (a) Organisms grow with time (b) Organisms must repair and maintain their structure (c) Movement of molecules does not take place among cells (d) Energy is essential for life processes

c) Movement of molecules does not take place among cells. Molecules move across the cells by active and passive transportation. Osmosis and... View Article

As a part of the eco-club activity, students were asked to raise a kitchen garden on the school premises. They were provided with some materials given in the box. List the other materials you would require. How will you plan the garden? Write the steps.

The following items are required—seeds and seedlings of vegetable plants from nursery, kitchen waste, water. A pit will be made to... View Article

The belief that the mother is completely responsible for the sex of the child is wrong because the child (a) gets sex chromosome only from the mother. (b) develops in the body of the mother. (c) gets one sex chromosome from the mother and the other from the father. (d) gets sex chromosome only from the father.

(d) gets sex chromosome only from the father. Humans have 23 pairs of chromosomes. Out of these 23 pairs, 22 pairs are Autosomes and only... View Article

Rainfall patterns depend on (a) the underground water table (b) the number of water bodies in an area (c) the density pattern of human population in an area (d) the prevailing season in an area

a) The underground water table More the number of water bodies in an area more is evaporation of water in that area. As a result, more clouds... View Article

Choose the correct statement: (a) Genes are located in the chromosomes. (b) The cell is located in the nucleus. (c) Chromosomes are located in the nucleolus. (d) Cell membrane surrounds the nucleus.

(a) Genes are located in the chromosomes Genes are the unit of inheritance located in the chromosomes. The other statements are incorrect, and... View Article

Read the following terms and select the pair that is related to the inheritance of characters. (a) cell wall and cell membrane (b) chromosome and mitochondria (c) chloroplast and cell membrane (d) chromosome and genes

(d) chromosome and genes Genes are segments of deoxyribonucleic acid (DNA) that contain the code for a specific protein that functions in one or... View Article

Aquatic animals in which fertilisation occurs in water are said to be: (a) viviparous without fertilisation. (b) oviparous with external fertilisation. (c) viviparous with internal fertilisation. (d) oviparous with internal fertilisation.

b) oviparous with external fertilisation. Fertilisation that occurs outside the body of an organism is known as external fertilisation. It... View Article

Choose the event that does not occur in photosynthesis (a) Absorption of light energy by chlorophyll (b) Reduction of carbon dioxide to carbohydrates (c) Oxidation of carbon to carbon dioxide (d) Conversion of light energy to chemical energy

d) Oxidation of carbon to CO2. Photosynthesis is the process by which plants use sunlight, water, and carbon dioxide to create oxygen and... View Article

Alka was making tea in a kettle. Suddenly she felt intense heat from the puff of steam gushing out of the spout of the kettle. She wondered whether the temperature of the steam was higher than that of the water boiling in the kettle. Comment.

The boiling point of water is 100°C. The temperature of boiling water does not rise instead of continuous supply of heat, as the extra heat... View Article

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