P-1 Carbon Compounds — Science STD 10 — Question

Draw a neat labelled diagram: Forth floatation.

When an insect sits on the flower of a plant then some particles A present in the top of little stalks in the flower attach to its body hair. When this insect now sits on the flower of another similar plant, then particles A attached to the hair of insect are put on the top of a flask-shaped organ at the centre of flower. The particle A grows a long tube b from the top of flask-shaped organ through which C moves down and reaches the bottom part of flask-shaped organ. Here C fuses with the nucleus of d contained in structure E. the fusion of C and D forms a new cell f which grows and develops into a seed of the plant.

1. What are particles A? What is the process of transferring A from one flower to another flower of similar plant by the insect known as?
2. What is the name of tube B?
3. What is C which moves down through the tube B?
4. Name D and E.
5. What is F?

Describe the exchange of gases which takes place in the leaves of a plant:

1. During daytime.
2. At night.

Sketch and explain the structure of DNA and various types of RNA.

Name the products of combustion of fossil fuels like coal and petroleum products. How do they affect us and our environment?

What is meant by the orbit of a satellite? On what basis and how are the orbits of artificial satellites classified?

There are two important fuels A and B both of which are extracted from deep inside the earth. Fuel A is a thick, dark, foul smelling liquid whereas fuel B is a black solid. Combustion of both the fuels produces products, C, D, E and F. The product C makes the rainwater only slightly acidic but it is mainly responsible for causing global warming. The product D is neither acidic nor basic. It is harmless and does not affect the environment in any way. Both E and F attack breathing system of humans and are mainly responsible for causing acid rain. In addition to combustion of fuels A and B, the product F is also formed when lightning occurs in the sky.

1. What are (i) fuel A, and (ii) fuel B?
2. Name (i) C (ii) D (iii) E, and (iv) F?
3. What is the process of formation of F during lightning known as?
4. Which fuel is supposed to be exhausted sooner : A or B?
5. Which fuel is mostly used for generating electricity at thermal power plants?

Why is it beneficial to use a satellite j launch vehicle made up of more than one stage?

When the branches of a plant growing in the field are pulled towards the ground and a part of them is covered with moist soil (leaving the tips of the branches exposed above the ground), then after some time new roots develop from the parts of branches buried in the soil. On cutting these branches from the parent plant, new plants are produced from the cut parts of branches which had developed roots.

1. What is this method of propagation of plants known as?
2. What type of branches should a plant have to be able to be propagated by this method?
3. Name any two plants which are grown for their flowers and propagated by this method.
4. Name any two plants which are grown for their fruits and propagated by this method.
5. Name one plant which gets propagated by this method naturally by forming runners (soft horizontal stems running above the ground).

Explain how, sex is determined in human babies.