The right answer is Schwann cells.
<span>Schwann cells, or neurolemmocytes, are peripheral glial cells. With oligodendrocytes, they make myelin sheaths around the axons of neurons, protecting them and increasing the speed of electric nerve impulses.</span>
Answer: A. scalp hairs grow constantly throughout life.
Explanation:
Hair is a squamous keratinized epithelium which is consist of multi-layered flat cells. Hair are made up of protein called "keratin".
The statement "scalp hairs grow constantly throughout life" is false because at a particular age or due to several factors scalp hairs stop growing.
Scalp hair growth rate depends on three main factors including sex (female hair grows faster than male), age (hair growth slows with age), and ethnicity (Asian hair grows slower than Caucasian hair).
Scalp hair growth stops because of follicle devitalization when the hair length become two or three feet.
Hence, the correct answer is A. "scalp hairs grow constantly throughout life".
Answer:
A sperm cell
Explanation:
A diploid cell has 46 chromosomes which is normally signified by somatic cells. Germ cells or gametes are haploid cells therefore they contain only 23 chromosomes. Male gamete contains 22 autosomes and one sex chromosome. That sex chromosome can be X or Y.
Female gamete does not have Y chromosome as a sex chromosome, it has only X chromosome as a sex chromosome. So Y chromosome in a human cell which have 22 autosomes determines that it is a male gametic cell or a sperm cell. Sperm cells that have a Y chromosome if fuses with female gamete produce male offspring(XY).
So the correct answer is- a sperm cell.
If lions attack the slowest animal in a herd, it is beneficial to the herd in the following ways:
1.) Evolutionarily, the faster herd members survive and breed, increasing the speed of the offspring and guaranteeing better survival for the future population.
2.) The lions focus on the straggling animal, allowing the rest of the herd to escape.
3.) The death of one herd member ensures the survival of many more.
The biome that exist closest to the Earth's poles are descibed as polar