Consider statements about plant tissues: 1. Xylem transports water upwards. 2. Phloem transports food bidirectionally. 3. Cambium is a permanent tissue. Which are correct? MCQ with Answer and Explanation

Explanation:
Xylem is a complex permanent tissue composed of tracheids, vessels, xylem parenchyma, and xylem fibers. It conducts water and dissolved minerals from roots to aerial parts unidirectionally. Phloem transports organic nutrients bidirectionally. Cortex is ground tissue for storage, epidermis provides protection. Xylem vessels are dead at maturity, with lignified walls.

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

Explanation:
Genes are specific sequences of DNA that code for proteins or RNA, and they are arranged linearly on chromosomes within the nucleus. DNA replication is semi-conservative, meaning each newly synthesized DNA molecule consists of one original parental strand and one newly synthesized strand, as proven by the Meselson-Stahl experiment. RNA is typically single-stranded, allowing it to fold into complex shapes and perform various functions, unlike the double-stranded DNA helix. Thus, statements 1 and 2 are correct.