<span>Melanin helps protect the skin against effects of the sun such as skin cancers and premature aging. In African American skin, melanin provides a sun protection factor (SPF) equivalent to 13.4 compared to 3.4 in white skin and thus the former have lower incidences of skin disorders associated with exposure to the sun.</span>
Answer: As a body cell grows, the ratio of SURFACE AREA to volume INCREASES. Before it grows to large, a cell will divide into two DAUGHTER cells. So that each new cell receives its own genetic instructions, the cell REPLICATES or copies, all of its DNA.
Explanation:
Answer:
6.7 minutes
Explanation:
In a solid such as rock, the primary wave can travel at 5 km/sec; it would take 400 seconds, or about 6.7 minutes to travel 2,000 km.
Answer:
As insect nymphs grow larger, their exoskeleton becomes too tight and they must replace it. Once a nymph outgrows its exoskeleton it will go through a process called molting, in which it leaves the old “skin” or exoskeleton behind. The new “skin” will harden and become the new exoskeleton
Explanation:
Answer: True
Explanation:
DNA is a biological evidence. It is a heredity material which is present in all organisms on earth. The DNA in humans can be taken as sample from nails, bones, blood, skin, hair and other sources.
The DNA samples can be taken so as to establish the identity of the culprit, victim or any one which is associated with crime.
The DNA evidence has applicability as a potent evidence in the court of law. Thus utmost care should be taken to preserve it's integrity until it is analysed and presented in the court of law.
Thus the DNA evidence should be collected and preserved in airtight containers so as to prevent the entry of airborne pathogens like bacteria, virus these can contaminate the sample evidence and can make the evidence not of any use.
