When plants and animals die, they become food for decomposers like bacteria, fungi and earthworms. Decomposers or saprotrophs recycle dead plants and animals into chemical nutrients like carbon and nitrogen that are released back into the soil, air and water.
Phagocytes are cells that protect the body by ingesting harmful foreign particles, bacteria, and dead or dying cells.
Answer:
The correct answer is "grey; central canal".
Explanation:
Grey matter refers to an area of the brain, brainstem and cerebellum comprised of unmyelinated neurons and other cells that has given its name for having a pinkish-grey color in the living brain. Grey matter is also present in the spinal cord in an are of three grey columns that are H-shaped and it is located around the central canal filled with cerebrospinal fluid
The human genome density ranges between 12-15 genes per Megabase pairs. This is because humans have approximately 2000 genes in a total of approximately 3 billion base pairs. However, some primitive organisms have an even larger gene density
than humans. An example is bacteria with gene densities ranging between 100 –
500 genes/Mb. Gene density is therefore
not a good characteristic in determining
the complexity of an organism.
Answer:
The correct answer is B. Worms move through changes in body structure caused by contraction of muscles compressing their watery fluid.
Explanation:
The hydroskeleton consists of a fluid-filled cavity, surrounded by muscles. The fluid pressure and the action of the muscles that border it, serve to change the body's shape and produce a movement such as digging or swimming. The successive contraction of various metamers, which are provided with bundles of circular and longitudinal muscle fibers, stretching and thickening parts of the body, allow it to move horizontally. Hydrostatic skeletons have a role in the locomotion of annelids, nematodes and other invertebrates. The hydroskeleton has similarities with the hydrostatic muscles.
