Answer:
Negative feedback mechanism may be defined as the system of the body in which the final output reduces the process and result in the less output. Negative feedback mechanism is important for the regulation of homeostasis.
The negative feedback mechanism maintains the constant body temperature. The change in body temperature is sensed by the receptors. The low body temperature initiates the hypothalamus to increase the physiological process. The blood vessels narrow, body start shivers and hormone stimulation increases body temperature. When the body temperature become normal, the hypothalamus will no longer be stimulated and stop its effect.
Answer:
16
Explanation:
For a species with four pairs of chromosomes, 16 gametic combinations are possible.
This is calculated by using the formula 2n
A normal human has two pairs of chromosome which calculated by 2*2=4 to give the possible gametic combinations. However in the case of 4 pairs of chromosomes it is calculated by 2*2*2*2= 16 possible genetic combinations.
Cell membrane separates cell from external environment whereas nuclear membrane separates nuclear environment form cell itself.
There is Nucleoplasm as a fluid under the nuclear envelope whereas cytoplasm under the cell membrane
Electronegativity.
If the difference in electronegativity for the atoms in a bond is greater than 0.4, we consider the bond polar. If the difference in electronegativity is less than 0.4, the bond is essentially nonpolar.
A) Chargaff discovered two rules that helped to reveal the structure of the double helicon DNA. Chargaff's rules claim that the DNA from any cell and any organism should have a 1: 1 ratio (base pair rule) of pyrimidine and purine bases, and more specifically that the amount of guanine is equal to the amount of cytosine, and the amount of adenine is equal to the amount of thymine. This form was found in both DNA strands.
B) James Watson and Francis Crick in 1953 proposed the first correct model of the double helicon DNA structure. Their model was based on only one X-ray diffraction image recorded by Rosalind Franklin and Raymond Gosling in May 1952, as well as information that the DNA bases ware paired, which came out of private communication with Erwin Chargaff during the previous years. Chargéff's rules played a very important role in determining the configuration of double helices for B-DNA as well as for A-DNA.
