1. Regulation of glucose blood levels is an example of negative feedback mechanism.
Negative feedback mechanism is a control mechanism involved in homeostasis maintain, in this case maintenance of glucose blood levels in normal range.
Negative feedback mechanism contains sensory system that detects the changes, control system that responds to change and activates mechanisms of effector system that reverse the changes in order to restore conditions to their normal levels.
• Pancreatic cells-sensors
• Insulin-control system
• Body cells- effector cells
2. Blood glucose levels change throughout the day because of the food consumption, but in healthy individuals levels of glucose are successfully regulated via the mechanism of hormones such as insulin and glucagon in a process called glucose blood regulation.
This tight regulation of pancreatic hormones is referred to as glucose homeostasis. Insulin lowers blood sugar and glucagon raises it.
3. If the beta cells are destroyed by an autoimmune disease (immune system attacks its own cells), there would be no insulin release, and consequently, the glucose blood levels would be increased.
Diabetes type I is a metabolic disorder caused by the destruction of insulin-producing pancreatic beta cells.
<span>Example of Trisomy 21 detected</span>... <span>the presence , which is found in Down syndrome, is calledtrisomy 21.</span> ... <span>Of these, Trisomy 21 and Trisomy 18 are the most common.</span> ... <span>XXX (Triple X syndrome); XXY (Klinefelter syndrome); XYY</span> ... <span>Turner syndrome (XO).
so i think all are right</span>
Step One - Obtain a clean microscope slide.
Step Two - Place a drop of liquid on the slide. This is the “wet” part of the wet mount. The liquid used depends on the type of cell being viewed:
If examining a plant cell, tap water can be used.
If examining an animal cell, physiological saline (or contact lens solution) must be used, because if plain water is used, the cell will explode from osmotic pressure. Unlike plant cells and bacteria, animal cells have no cell wall to structurally support them.
Step Three - Obtain the specimen to be used. Some introductory biology classics for viewing include:
Skin of an onion bulb: In order to view the cells, a very thin layer of skin must be obtained. Take a single layer of onion and bend it towards the shiny side. After it snaps, pull gently, and a transparent layer of skin, similar to Scotch tape, will appear.
Elodea leaf: Elodea leaves are two cell layers thick. The cells in one layer are smaller than the cells in the other, so elodea leaves can be used to better understand a microscope's depth of field.
Cheek cells: Human epithelial cells can be obtained by gently rubbing a toothpick on the inside of the mouth, and then swirling the toothpick in the physiological saline on the slide.
Pond water: Obtaining some water from a pond makes wet mount preparation a breeze, since the water and the specimens are both included.
Hope this helps
The answer is: A. True
Complex sugars or polysaccharides are composed of basic units called monosaccharides that are linked via glycosidic bonds. Glycosidic bond is formed through condensation reactions (water is released) that occur between a hydroxyl (OH) oxygen atom on one sugar and the α-anomeric form of C-1 on the other. There are are two types of glycosidic bonds:
- 1,4 alpha ( the OH is below the glucose ring)
- 1,4 beta glycosidic bonds (the OH is above the glucose ring)
Amylase is an enzyme that breaks down starch into smaller glucose molecules, it act on α-1,4-glycosidic bonds and it works in mouth where the digestion begins (salivary amylase) . Maltase breaks down maltose into glucose; sucrase, breaks down sucrose into glucose and fructose; and lactase, which breaks down lactose into glucose and galactose work in small intestine and also act on α-1,4-glycosidic bonds.
