Answer:
As the food moves through the gastrointestinal tract, and when it reaches the duodenum via the stomach, the food or the paste, that is, chyme becomes acidic because of the presence of acid in the stomach. When this acidic chyme moves towards the first section of the duodenum, it results in the discharging of cholecystokinin and secretin from the duodenal mucosa, which further instigates the pancreas to discharge alkaline pancreatic juice that comprises pancreatic enzymes and bicarbonate ions.
Now the bicarbonate ions will turn the chyme alkaline and is now known as chyle. It is made alkaline as the pancreatic enzyme needs alkaline pH to function on food. The intestinal juice is also secreted due to the discharging of similar hormones as mentioned above. However, the difference is that both the mechanical stimulus and nervous stimulus results in the discharging of intestinal juice, though it is not true for pancreatic juice.
Answer:Oxygen availability is often a limiting factor for cell survival, and it is generally ... An organism is faced with the following problem: How can the composition of ISF be ... which ensures proper exchange of oxygen and carbon dioxide; the kidney, ... to carry out its function of bringing blood close to cells so that the exchange of ...
by RN Pittman · 2011 · Cited by 54 · Related articles
Explanation:
Answer:
The cells of the body's surface form the outer layer of skin. Inside the body, epithelial cells form the lining of the mouth and alimentary canal and protect these organs. Epithelial tissues help in absorption of water and nutrients
The brain is protected by the bones of the skull and by a covering of three thin membranes called meninges. The brain is also cushioned and protected by cerebrospinal fluid. This watery fluid is produced by special cells in the four hollow spaces in the brain, called ventricles.
Explanation:
1) variation in traits.
population of beetles: equal brown and green numbers in population.
2) differential reproduction.
Natural habitat is in trees. Green leaves hide green beetles.
The brown beetles are noticed by birds in the area.
Birds eat brown beetles.
More green beetles survive than brown beetles
3) heredity
Green beetles reproduce in greater numbers than brown beetles
4) end result
Beetle population changes from brown and green to mostly green beetles.
