The pores present in the bark of woody stems for gaseous exchange are called: MCQ with Answer and Explanation

Explanation:
Insects have an open circulatory system where hemolymph bathes organs directly, not always in vessels. Thus, 3 is incorrect.

Explanation:
Vitamin K is a cofactor for the enzyme γ-glutamyl carboxylase, which adds carboxyl groups to glutamic acid residues in clotting factors II, VII, IX, and X, allowing them to bind calcium and participate in coagulation. Deficiency leads to bleeding tendency.

Explanation:
Biochemical Oxygen Demand (BOD) measures the amount of dissolved oxygen required by aerobic bacteria to decompose organic matter in water; high BOD indicates severe organic pollution. Eutrophication is the excessive enrichment of water bodies with nutrients (like nitrates and phosphates), leading to algal blooms and oxygen depletion. Biological magnification is the progressive increase in the concentration of non-biodegradable toxins (like DDT) at each successive trophic level, not a decrease. Thus, statements 1 and 2 are correct.