Consider statements about biotechnology: 1. Gene therapy aims to correct genetic defects. 2. Transgenic animals have foreign DNA in their genome. 3. Biopesticides are highly toxic to humans. Which are correct? MCQ with Answer and Explanation
Consider statements about biotechnology: 1. Gene therapy aims to correct genetic defects. 2. Transgenic animals have foreign DNA in their genome. 3. Biopesticides are highly toxic to humans. Which are correct?
A. 1, 2 and 3
B. 1 and 2 only
C. 2 and 3 only
D. 1 and 3 only
Answer: Option B
Solution (By JKSSB Mock Tests)
Gene therapy is an experimental technique that involves introducing genes into a patient's cells to correct or compensate for genetic defects causing disease. Transgenic animals have had their genome deliberately altered by the insertion of foreign DNA from another species. Biopesticides, derived from natural materials like bacteria, plants, or minerals, are generally target-specific and non-toxic to humans and the environment, unlike synthetic chemical pesticides. Thus, statements 1 and 2 are correct.
Explanation:
Most bacteria possess a single circular double-stranded DNA molecule located in the nucleoid region. Some bacteria may also have linear chromosomes or multiple chromosomes, but the typical prokaryotic chromosome is circular. Eukaryotes have linear chromosomes. Plasmids are small, circular extra-chromosomal DNA in bacteria.
Explanation:
Thyroxine (T₄) and triiodothyronine (T₃) from the thyroid gland increase the metabolic rate of most tissues, heat production, and oxygen consumption. Insulin and glucagon regulate glucose, cortisol is a stress hormone with metabolic effects but not the primary basal regulator. Hypothyroidism leads to decreased BMR.
Explanation:
Abscisic acid (ABA) is called the stress hormone because it accumulates under adverse conditions (drought, cold) and triggers adaptive responses like stomatal closure. It also promotes seed dormancy and inhibits germination. Gibberellins break seed dormancy, cytokinins promote cell division, ethylene promotes fruit ripening. ABA is antagonistic to gibberellins.
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