Answer:
Explanation
The Axon or nerve fibre is a long, thin projection of the neuron or nerve cells that sends signals in the form of electrical impulses from the cell body (soma) to the synaptic terminals. The axons are of two types: myelinated and unmyelinated. The unmyelinated axons lack myelin sheaths which make the transmission of electrical impulses slower while the myelinated axons transmit electrical impulses faster.
<span>Plants and animals all have a range of limiting (ecological minimum and maximum) for certain environmental factors. The organism will survive provided the temperature, humidity, air etc are maintained within critical limits.</span>
Organisms that reproduce sexually produce sex cells, or gametes, that carry a single set of chromosomes, the haploid number for the species. In contrast, body, or somatic, cells are the regular cells that form the organism’s tissues and organs. Somatic cells of sexual organisms have the diploid number of chromosomes, one set from each parent. Both cell types undergo mitosis, but only the primary reproductive cells, or gametocytes, also undergo meiosis.
Answer:
Evidence for evolution comes from many different areas of biology:
Anatomy. Species may share similar physical features because the feature was present in a common ancestor (homologous structures).
Molecular biology. DNA and the genetic code reflect the shared ancestry of life. DNA comparisons can show how related species are.
Biogeography. The global distribution of organisms and the unique features of island species reflect evolution and geological change.
Fossils. Fossils document the existence of now-extinct past species that are related to present-day species.
Direct observation. We can directly observe small-scale evolution in organisms with short lifecycles (e.g., pesticide-resistant insects).
