Answer:
In the cardinals, if the females start using a different criterion than the color of the feather when they choose couple, most likely to happen is that decreased variation in the shades of red because no form of the trait is advantageous.
Explanation:
Options for this question are:
- <em>Increased variation in the shades of red because the selection pressure has been relieved.</em>
- <em>Increased variation in the shades of red because the cardinals try different ways to impress the females.</em>
- <em>Decreased variation in the shades of red because no form of the trait is advantageous.</em>
- <em>Decreased variation in the shades of red because the only reason for variation was selection pressure.</em>
In the context of natural selection, male cardinals court females using the coloring of their feathers as a form of sexual selection. This means that the shades of red in the feathers are a selection criterion in these birds, and the more visible shades represent an advantage.
But, if the selection criterion was not the color of the feathers, this trait would no longer represent an advantage in the competition between the males to be chosen as a mate. Instead, the trait that would determine sexual selection would be the one that experiences an increase in its variation<em>.</em>
Answer:
1) Skull and Vertebral column
2) Meninges
3) Cerebrospinal fluid.
Explanation:
Central Nervous system:
CNS is the abbreviation of Central Nervous system. CNS controls the whole body functions so it is the most important component of the body. CNS consist of two parts 1) Brain and 2) Spinal cord
Both of these organs are very important and hence need to be protected. Nature provided these organs with certain protective mechanisms these includes
1) Skull and Vertebral column:
Skull is present around brain and vertebral column is present around spinal cord. These structure provides mechanical support to soft parts of CNS.
2) Meninges:
These are the membranes that provide antiseptic environment to the brain and hence protect it from microbes and other harmful substances.
3) Cerebrospinal fluid:
This fluid is present inside meninges which nourishes the brain and protect it from mechanical stresses.
<span>The ecosystem has land but with high sea levels</span>
Answer:
peptide antigens by MHC class II molecules
Explanation:
Helper T cells are activated by peptide antigens by MHC class II molecules. These antigens express on the surface of antigen-presenting cells (APCs). After activation, the T helper cells divide and secrete cytokines to assist the immune response.
Through the roots which soak up the water from surrounding soil