The Nervous System and Sense Organs — Biology STD 10 — Question

What are the important features of osmosis?

Which of the following secrete(s) hormone, relaxin, during the later phase of pregnancy?

Who had said that "transpiration is a necessary evil"?

What type of reflex is the following?
Blinking of the eye

Red blood cells are also called as erythrocytes. Cellular component of blood, millions of which in the circulation of vertebrates give the blood its characteristic colour and carry oxygen from the lungs to the tissues. The mature human red blood cell is small, round, and biconcave; it appears dumbbell-shaped in profile. The cell is flexible and assumes a bell shape as it passes through extremely small blood vessels. It is covered with a membrane composed of lipids and proteins, lacks a nucleus, and contains hemoglobin-a red ironrich protein that binds oxygen.
Answer the following questions in context to RBC.
(iii) Choose the correct statement:

A pair of corresponding chromosomes of the same shape and size but one from each parent.

Tom, a biology student, is studying the theory of natural selection proposed by Charles Darwin. He wonders how natural selection applies to the evolution of antibiotic resistance in bacteria. Which of the following best describes how natural selection contributes to the evolution of antibiotic resistance in bacteria?

The growing leaves show

A piece of blue cobalt chloride paper is clipped to the lower surface of a fresh leaf and is then covered with plastic, as shown. After a few minutes, part of the paper turns pink, showing that water is present.


Which process is carried out by leaves that causes the paper to turn pink?

Two hydrogen bonds are present between