Answer:
Explanation:
The switch from glutamic acid to valine in position 6 of hemoglobin (HB) forms the basis of sickle cell anemia disease pathology.
Valine is hydrophobic and it's chain is shorter than glutamic acid. The lack of the carboxylic acid and shortness of valine will result in loss of the ionic interactions formed between the glutamic acid's carboxylic group and other amino acids. A hydrophobic cavity will form in the beta sheet of HB due to the short and hydrophobic structure of valine. For these reasons, the HB molecule will be less stable and insoluble in water. The insolubility is thought to be caused by fibril formation between the valine interacting with hydrophobic pocket residues of the adjacent HB molecule. This would in turn affect binding of oxygen to HB.
Natural Selection proposes that organisms that are better adapted to their environment are able to survive and reproduce.
Even though these frogs are the same species, their shades of green is what helps them to survive in their habitat. In this case, frogs with a lighter shade of green are able to be seen by predators easier, whereas frogs with darker shades are able to blend in (camouflage) more with their surroundings. After a period of time, due to them being easily seen, lighter-shaded green frogs will die off.
To anseer your question, natural selection would have a gradual affect on the frequency of the alleles. Lighter-green allele frequencies would eventually cut off, and darker-green allele frequencies will increase.
Hopefully the following image will help:
As seen in the image, (please forgive the quality, as I had drawn this on some random kids drawing site on the internet...) you can see the affects of natural selection on the allele frequencies. The brighter-green shades gradually decrease over time, as the darker shades increase.
Hope you find this helpful.
Answer:
He identified that diseases are caused by malfunctioning cells.
That all cells arise from pre-existing cells.
Answer: B
Explanation: The DNA in the nucleus can be transcribed in mRNA, which can then leave the nucleus and be translated into proteins, which make up physical traits and characteristics.
D it causes lava to rush out faster