We must be aware that the lungs supply oxygenated blood to the left atrium of the heart. Gradually, it contracts and blood is allowed to enter the next chamber (the left ventricle) as it expands. When the left lower chamber ...

The wall of the alimentary canal consists of muscular layers. The rhythmic contraction and relaxation of these muscles move the food forward. This is called peristalsis, which occurs throughout the abdomen. It is a type of movement that facilitates the ...

Remember, the pH value of water is 7. Acetic acid (CH₃COOH) is a weak acid while hydrochloric acid (HCl) is a strong acid. Hence, the correct increasing order of acidic strength is water < acetic acid < hydrochloric acid.

Robert Hooke in 1665, while examining a thin slice of cork, discovered dead cells. He used the word cell, which is derived from Latin, that means ‘ a little room’ to describe these units of cork slice.

Companion cells are characteristic element of phloem tissue associated with the sieve tubes in the angiosperms. Thus, they are the part of vascular tissue system. They are absent in pteridophytes and gymnosperms. Guard cells and subsidiary cells are associated with ...