Questions

Joseph Priestley and Carl Wilhelm Scheele both independently discovered oxygen in the year 1774, but Priestly is usually given credit for the discovery.

Plants grow in size both in height and in grith. Enlargement  of cells already present cannot contribute much to the growth. Only addition of more and more cells could increase the size of the plant considerably.

When you can't hear it is called as Deaf.

Most of the known extrasolar planets resembles the planet Jupiter in the solar system.

Secondary succession means in an ecosystem renewal of itself after all or a portion has been destroyed.

After a forest fire, the whole forest had destroyed but after that again renewal of that forest is also an example of secondary succession.