A process which releases Nitrogen into the atmosphere.

Here are the solutions for the questions from the image:

39. A process which releases Nitrogen into the atmosphere.

• Denitrification is the process by which nitrates in the soil are converted back into gaseous nitrogen ($\text{N}_2$) and released into the atmosphere. The correct option is D. Denitrification.

40. Movement of substances against their concentration gradient.

• Active transport is the movement of molecules across a cell membrane from a region of lower concentration to a region of higher concentration, requiring energy. The correct option is D. Active transport.

SECTION VI (QUESTIONS 41-50)
Directions: This group of questions deals with biological situations. Each situation is followed by a set of questions. Select the best answer for each question.

41. The apparatus below was set up to investigate the effect of an external factor on photosynthesis. What is the role of soda lime in the apparatus above?

• Soda lime is a chemical mixture used to absorb carbon dioxide. In this experiment, its role is to remove $\text{CO}_2$ from the air inside bell jar A, creating a $\text{CO}_2$-free environment to show that $\text{CO}_2$ is necessary for photosynthesis. The correct option is D. To absorb $\text{CO}_2$ present in the bell jar.

42. Pyrogallic acid was used in an experiment to show that oxygen is necessary for seed germination. What is the role of pyrogallic acid in the experiment?

• Pyrogallic acid is a chemical that absorbs oxygen. In an experiment to show oxygen's necessity, its role would be to remove oxygen from the experimental setup. The correct option is B. To absorb $\text{O}_2$.

43. Which of the equations below represent the process of fermentation?

• Fermentation is an anaerobic process that breaks down glucose. Option C represents alcoholic fermentation, where glucose is converted into ethanol and carbon dioxide. Option D represents lactic acid fermentation, where glucose is converted into lactic acid. Both are forms of fermentation. In many general biology contexts, alcoholic fermentation (Option C) is a common example. The correct option is C. $\text{C}_6\text{H}_{12}\text{O}_6 \to 2\text{C}_2\text{H}_5\text{OH} + 2\text{CO}_2 + \text{Energy}$.

44. Blood vessels constrict in cold weather such that:

• In cold weather, blood vessels near the skin constrict (vasoconstriction) to reduce blood flow to the body surface. This minimizes heat loss from the body, helping to conserve body heat. The correct option is A. Less blood flows to the body surface and conserve heat.

45. The movement of molecules of a substance from a region of high concentration to a region of low concentration is?

• Diffusion is the net movement of particles from an area of higher concentration to an area of lower concentration. The correct option is A. Diffusion.

46. Which of these tests will detect presence of protein in food and be the colour change?

• The Biuret test is used to detect the presence of proteins. In the presence of proteins, the solution changes color to purple. The correct option is A. Biuret test / purple colour.