Answer: It is important for cells to divide so you can grow and so your cuts heal. It is also important for cells to stop dividing at the right time. If a cell can not stop dividing when it is supposed to stop, this can lead to a disease called cancer. Some cells, like skin cells, are constantly dividing.
Explanation:
Answers: examples of host defence mechanism include: Innate anatomical and physiological barriers, Innate cellular and chemical defenses.
Explanation:
The capability of the human body to resist almost all types of organisms or toxins that tend to damage the tissues and organs is known as IMMUNITY. This host defence mechanism can be classified into INNATE or adaptive immunity.
The immunity that results from general processes, rather than from processes directed at specific disease organisms is called the INNATE IMMUNITY. The anatomical and physiological barriers of the innate immunity provides the first line of defence against pathogens. Examples of these barriers of the innate immunity includes:
--> Destruction of swallowed organisms by the low stomach pH and digestive enzymes
--> The vigorous mucociliary clearance mechanisms of the respiratory airways and lungs.
--> Resistance of the skin to invasion by organisms
While examples of innate cellular and chemical defenses include:
--> Phagocytosis of bacteria and other invaders by white blood cells and cells of the tissue macrophage System
--> lysozymes, a mucolytic polysaccharide that attacks bacteria and cause them to dissolute.
--> basic polypeptides which react and inactivate certain types of gram- positive bacteria
-->natural killer lymphocytes that can recognize and destroy foreign and tumor cells.
The spinal cord is the link
Answer:
After being hunted almost to extinction, the humpback whale population has rebounded dramatically. Rapidly melting Antarctica ice poses a threat to coastal cities, but there is at least one species that is benefiting: Humpback whales are flourishing these days, due to an abundance of krill.
Pre-hunting population size may have been as many as 200,000-300,000 whales. They were estimated to number around 2,300 in 1998 and to be increasing between 2.4-8.4% per year. The IWC is undertaking an assessment of Antarctic blue whales at present.
