Matter in Our Surroundings — Science STD 9 — Question

Which one is made of dead cells?

1. Sclerenchyma
2. Tracheids
3. Vessel
4. All the above

Soil erosion is caused due to:

1. Strong wind.
2. Heavy rains.
3. Keeping the fields fallow for a long.
4. All of these.

Find out the correct sentence.

1. Hybridization means crossing between genetically dissimilar plants.
2. Cross between two varieties is called as inter-specific hybridization.
3. Introducing genes of desired characters into a plant gives genetically modified crop.
4. Cross between plants of two species is called as inter varietal hybridization.

1. (i) and (ii)
2. (ii) and (iv)
3. (ii) and(iii)
4. (iii) and (iv)

When a wave travels from the one medium to another, the quality which will not change is its:

How much work they do in just holding it?

What is one major difference between a human skin cell and a human egg cell?

In which type of cell division two identical daughter cells are formed:

'Organic farming’ does not include:

A group of cells alike in form, function and origin are called __________.

What is the source of centripetal force that a planet requires to revolve around the Sun?