PART - 1 CH - 4 Carbon and Its Compounds — Science STD 10 — Question

Explain menstruation.###What happens if the egg is not fertilised in woman?

Draw a labelled diagram of cross section of a leaf and mention the location of chlorophyll.

Bharat had an electric iron. He connected it into two-pin plug. Obviously the green wire was left unconnected.
After few days, once his sister got a severe electric shock while ironing the clothes. Bharat called the electrician. He told that this situation could have been avoided if she would have connected the green wire also by using a three-pin plug. Bharat learnt a lesson.
(1) Which terminal gets connected by using a green wire?
(2) What care should Bharat take to avoid such mistakes?
(3) If you were the electrician, what else would you do apart from mere explaining to Bharat?

Write a note on detergents.

Draw a ray diagram showing the position, nature and size of the image formed by a convex mirror of small aperture, when an object is placed infinite distance from the mirror and give the description about the position, nature and size of the image.

Medha observed that the tubelights in the corridor of her school were always switched on the whole day. She brought the matter to the notice of her class teacher who talked to the Principal about it. The Principal took immediate action.
(1) Medha helped this way to reduce air pollution. Explain how.
(2) What values do you learn from Medha in this episode?
(3) What steps can the school take to get electricity consumption reduced?

State the difference in meaning between zygote, embryo and foetus.

What is a free electron? Explain conducting and nonconducting materials in terms of it.

Write a note on twinkling of stars.