The cartilaginous structures<span> that ring most mammalian tracheae are ... The </span>trachea<span> is</span>lined<span> with a moist mucous-membrane layer composed of </span>cells<span> containing small hairlike projections called </span>cilia<span>. ... </span>Such<span> outgrowths could </span>have<span> been useful to insects exposed by the drying up of a temporary aquatic.
IMPORTANT! * MARK AS BRAINLIEST </span><span>ANSWER !!!! *</span>
It is distinctive, widespread, abundant and limited in geologic time. Because most fossil<span>-bearing rocks formed in the ocean, the major </span>index fossils<span> are marine organisms. That being said, certain land organisms are useful in young rocks and in specific regions.</span>
Answer:
Genetic drift.
Explanation:
Genetic variation is the change in the genome of the organisms. The genetic variation might occur in the population due to the natural selection, mutation and genetic drift.
As the information given in the population, the variation is possible due to the genetic drift. This mainly occur due to the random sample of the small population and might cause the complete loss of the particular gene. The genetic variation might decreases in the organisms.
Thus, the answer is genetic drift.
Thew correct answer is amino-acids
Amino acids are essential to all life on earth. They are organic molecules comprised out of the amino (NH2) and acidic ( COOH) compound. The twenty amino acids can bound to one another with peptide bonds and form different complex structures called proteins. Proteins are important structural part of cells, enzymes and hormones, and without them the life as we know couldn't exist.