Some plant leaves have extensions from their upper epidermal surfaces known as a)trichomes b)cuticles c)pericycles d)none of the above

The correct answer is option (A) trichomes.

Trichomes are the fine extensions from the epidermal surfaces covering the plant body. They are the result of epidermal cell division. They can be unicellular, multicellular and even glandular. They are characteristically  present on the epidermal surfaces of leaves and roots. They reflect the solar radiation and help in mainitaining the internal temperature and reducing water loss. In roots, they absorb water and minerals and in leaves, they reduce water loss, lower the plant temperature. Plants may use trichomes to detect herbivore attacks as a defense mechanism.

ans.

dna fingerprinting is defined as a process that determines the dna characteristics of an individual. these dna characteristics are unique among individuals as their fingerprints, so it is known as dna fingerprinting.

steps of dna fingerprinting includes extraction of dna from sample, amplification of dna, restriction digestion of amplified dna, and then analysis of dna by gel electrophoresis, respectively.

thus, the next step performed by the scientist is 'to cut the amplified dna (obtained by polymerase chain reaction) by restriction enzymes that cleave the dna into fragments and their analysis.'