The blood vessel with the thinnest wall, allowing exchange of substances, is: MCQ with Answer and Explanation

Explanation:
Bt cotton contains cry genes from Bacillus thuringiensis, producing insecticidal proteins toxic to bollworms, reducing pesticide use.

Explanation:
Natural selection is the process where organisms with traits better suited to their environment are more likely to survive and reproduce, leading to adaptation of the population over time. Mutations, which are random changes in the DNA sequence, are the ultimate source of all new genetic variation upon which evolutionary forces act. Evolution is a population-level phenomenon, defined as a change in allele frequencies over generations; it does not occur within a single individual's lifetime. Thus, statements 1 and 2 are correct.

Explanation:
Sedimentary rocks, such as limestone, shale, and sandstone, form in layers from accumulated sediments and preserve remains of organisms as fossils. Igneous rocks from volcanic activity and metamorphic rocks formed under high temperature/pressure rarely contain fossils. The fossil record provides evidence for evolution, showing gradual changes in species over geological time. Fossils include bones, shells, imprints, and amber inclusions.