Answer:
1. C
2. All cells of your body have the same DNA/genetic information but cell differentiation causes some genes to turn off and some to turn off. The activated genes are coded for which produce proteins and amino acids allowing cells to differentiate. E.g. Neurons and epithelial cell have same genetic information, however the genes coding for neurons in epithelial cells are turned off or deactivated which make them epithelial cells
A pathogen is a microorganism that is able to cause disease in a plant, animal or insect. Pathogenicity is the ability to produce disease in a host organism. Microbes express their pathogenicity by means of their virulence, a term which refers to the degree of pathogenicity of the microbe. Hence, the determinants of virulence of a pathogen are any of its genetic or biochemical or structural features that enable it to produce disease in a host.
The relationship between a host and a pathogen is dynamic, since each modifies the activities and functions of the other. The outcome of such a relationship depends on the virulence of the pathogen and the relative degree of resistance or susceptibility of the host, due mainly to the effectiveness of the host defense mechanisms. Staphylococcus aureus, arguably the most prevalent pathogen of humans, may cause up to one third of all bacterial diseases ranging from boils and pimples to food poisoning, to septicemia and toxic shock. Electron micrograph from Visuals Unlimited, with permission.
The Underlying Mechanisms of Bacterial Pathogenicity
Two broad qualities of pathogenic bacteria underlie the means by which they cause disease:
1. Invasiveness is the ability to invade tissues. It encompasses mechanisms for colonization (adherence and initial multiplication), production of extracellular substances which facilitate invasion (invasins) and ability to bypass or overcome host defense mechanisms.
2. Toxigenesis is the ability to produce toxins. Bacteria may produce two types of toxins called exotoxins and endotoxins. Exotoxins are released from bacterial cells and may act at tissue sites removed from the site of bacterial growth. Endotoxins are cell-associated substance. (In a classic sense, the term endotoxin refers to the lipopolysaccharide component of the outer membrane of Gram-negative bacteria). However, endotoxins may be released from growing bacterial cells and cells that are lysed as a result of effective host defense (e.g. lysozyme) or the activities of certain antibiotics (e.g. penicillins and cephalosporins). Hence, bacterial toxins, both soluble and cell-associated, may be transported by blood and lymph and cause cytotoxic effects at tissue sites remote from the original point of invasion or growth. Some bacterial toxins may also act at the site of colonization and play a role in invasion. Acid-fast stain of Mycobacterium tuberculosis, the agent of tuberculosis (TB). The bacteria are the small pink-staining rods. More than one-third of the world population is infected. The organism has caused more human deaths than any other bacterium in the history of mankind. Although its ability to produce disease is multifactorial, it is not completely understood. American Society of Microbiology, with permission.
Answer:
Here are some explanations from 0nline so if you want rewrite in your own words
hope this helps :))
blood glucose-
"The control of blood sugar (glucose) by insulin is a good example of a negative feedback mechanism. When blood sugar rises, receptors in the body sense a change. In turn, the control center (pancreas) secretes insulin into the blood effectively lowering blood sugar levels."
"If the blood glucose level is too low, the pancreas releases the hormone glucagon. This travels to the liver in the blood and causes the break-down of glycogen into glucose. The glucose enters the blood stream and glucose levels increase back to normal. This is an example of negative feedback."
body temperature-
" Body temperature is regulated by negative feedback. The stimulus is when the body temperature exceeds 37 degrees Celsius, the sensors are the nerve cells with endings in the skin and brain, the control is the temperature regulatory center in the brain, and the effector is the sweat glands throughout the body."
"Body temperature is controlled by the hypothalamus in the brain. If the hypothalamus detects that the body is too hot, the response is that the body begins to sweat to try and reduce the temperature back to the correct level."
"Negative feedback (or balancing feedback) occurs when some function of the output of a system, process, or mechanism is fed back in a manner that tends to reduce the fluctuations in the output, whether caused by changes in the input or by other disturbances."
"Negative feedback brings a system back to its level of normal functioning. Adjustments of blood pressure, metabolism, and body temperature are all negative feedback"
Answer:
D most likely. As the moon revolves around Earth, the different amounts of the sunlit side faces Earth
Explanation:
We never really see the other sides of the moon, it's always facing one side to us.
