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If the key in the arrangement is taken out (the circuit is made open) and magnetic field lines are drawn over the horizontal plane ABCD, the lines are (a) concentric circles (b) elliptical in shape (c) straight lines parallel to each other (d) concentric circles near the point O but of elliptical shapes as we go away from it

c) Straight lines parallel to each other If the key in the arrangement is taken out (the circuit is made open) then there will be no... View Article

Choose the incorrect statement from the following regarding magnetic lines of the field (a) The direction of the magnetic field at a point is taken to be the direction in which the north pole of a magnetic compass needle points (b) Magnetic field lines are closed curves (c) If magnetic field lines are parallel and equidistant, they represent zero-field strength (d) The relative strength of the magnetic field is shown by the degree of closeness of the field lines

(c) If magnetic field lines are parallel and equidistant, they represent zero-field strength They have uniform magnetic field and doesn’t... View Article

Write how the following seeds are dispersed. (a) Seeds with wings. (b) Small and light seeds. (c) Seeds with spines/hooks.

(a) Seeds with wings are dispersed by wind. Due to the winged structure, the wind can easily blow off these seeds to different locations.... View Article

The male and female gametes fuse to form a _(a) during the process of _(b)__. This grows into an _(c)__ which is enclosed within a seed. After fertilisation the ovules develop into _(d)__ and the ovary develops into a _(e)____ .

The male and female gametes fuse to form an (a) zygote during the process of (b) fertilization. This grows into a (c) embryo which is enclosed... View Article

Coconut is a large and heavy fruit. How is it adapted for dispersal by water?

Even though coconut is large and heavy, it contains an outer fibrous coat which has the ability to float on water. It can drift in water bodies... View Article

When you keep food items like bread and fruits outside for a long time especially during the rainy season, you will observe a cottony growth on them. (a) What is this growth called? (b) How does growth take place?

(a) The growth is called a mould. It is formed by fungus.They are fast-growing fungi and have a cottony appearance (b) The growth takes place... View Article

One morning as Paheli strolled in her garden she noticed many small plants which were not there a week ago. She wondered where they had come from as nobody had planted them there. Explain the reason for the growth of these plants.

Sometimes, plants grow without a human support. New plants are produced from seeds or from vegetative parts. The seeds developed in the parent... View Article

Boojho had the following parts of a rose plant – a leaf, roots, a branch, a flower, a bud and pollen grains. Which of them can be used to grow a new rose plant?

Branch, pollen grains. Rose flower is a bisexual flower. Rose plant can be grown by vegetative propagation as well as sexual... View Article

Pick the odd one out from the following on the basis of mode of reproduction and give reason for it. (sugarcane, potato, rice, rose)

Rice Vegetative propagation is an asexual method of plant reproduction that occurs in its leaves, roots and stem. This can occur through... View Article

Fungus, moss and fern reproduce by a common method of asexual reproduction. Name the method.

Spore formation The method of asexual reproduction found in fungus, moss and fern is spore formation. The parent plant releases spores into the... View Article

Pollination refers to the (a) transfer of pollen from the anther to the ovary. (b) transfer of male gametes from the anther to stigma. (c) transfer of pollen from the anther to stigma. (d) transfer of pollen from the anther to the ovule.

(c) transfer of pollen from anther to stigma. Pollination is a method where pollen grains are picked from an anther, which is the male part of... View Article

Which of the following statements is/are true for sexual reproduction in plants? (i) Plants are obtained from seeds. (ii) Two plants are always essential. (iii) Fertilisation can occur only after pollination. (iv) Only insects are agents of pollination. Choose from the options given below. (a) (i) and (iii) (b) (i) only (c) (ii) and (iii) (d) (i) and (iv)

a) (i) and (iii) In sexual reproduction, new plants are produced from seeds.Two plants are not always necessary for sexual reproduction. In... View Article

The ovaries of different flowers may contain (a) only one ovule (b) many ovules (c) one to many ovules (d) only two ovules

(c) one to many ovules It is the ductless reproductive gland that holds a lot of ovules. It is the part of the plant where the seed formation... View Article

The ‘eye’ of the potato plant is what (a) the root is to any plant. (b) the bud is to a flower. (c) the bud is to Bryophyllum leaf. (d) the anther is to stamen

c) The bud is to Bryophyllum leaf. The leaves of a Bryophyllum plant have special buds in their margins which may get detached from the leaves,... View Article

Seeds of drumstick and maple are carried to long distances by wind because they possess (a) winged seeds (b) large and hairy seeds (c) long and ridged fruits (d) spiny seeds

a) Winged seeds Seeds of maple and drumstick have wings. The winged seeds help them to travel long distances by wind. Seeds of drumstick and... View Article

Lila observed that a pond with clear water was covered up with green algae within a week. By which method of reproduction did the algae spread so rapidly? (a) Budding (b) Sexual reproduction (c) Fragmentation (d) Pollination

c) Fragmentation An alga breaks up into two or more fragments. These fragments or pieces grow into new individuals. This process continues and... View Article

Which of the following parts of a plant take part in sexual reproduction? (i) Flower (ii) Seed (iii) Fruit (iv) Branch Choose the correct answer from below. (a) (i) and (ii) (b) (i), (ii) and (iii) (c) (iii) and (iv) (d) (ii), (iii) and (iv)

b) (i), (ii) and (iii) Flowers take part in sexual reproduction in plants. Seed forms as a result of the sexual reproduction process. Fruits... View Article

While learning to ride a bicycle Boojho lost his balance and fell. He got bruises on his knees and it started bleeding. However, the bleeding stopped after some time. (a) Why did the bleeding stop? (b) What would be the colour of the wounded area and why? (c) Which type of blood cells is responsible for clotting of blood?

a) Bleeding stopped due to formation of blood clots. b) Dark red due to clotting of blood. c) Platelets are responsible for clotting of blood.... View Article

Fill in the blanks of the following paragraph using just two words – arteries and veins. _(a)_ carry oxygen-rich blood from the heart to all parts of the body and _ (b)_ carry carbon dioxide-rich blood from all parts of the body back to the heart. _ (c)_ have thin walls and (d)_ have thick elastic walls. Blood flows at high pressure in _ (e). Valves are present in (f) _ which allow blood to flow only towards the heart. (g)_ divide into smaller vessels. These vessels further divide into extremely thin tubes called capillaries. The capillaries join up to form (h)___.

Arteries and Veins are two different types of blood vessels in the circulatory system and are mainly involved in circulating blood throughout the... View Article

Read the following terms given below. (Root hairs xylem urethra arteries kidneys veins atria capillaries heart ureter phloem urinary bladder) Group the terms on the basis of the categories given below. (a) The circulatory system of animals. (b) Excretory system in human. (c) Transport of substances in plants.

The terms on the basis of the categories are: a) Arteries, atria, capillaries, veins, heart are the circulatory systems of animals. The human... View Article

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