Nucleotides are a base pair and they fit together because their shape allows them to bond. The A-T pair frames two hydrogen bonds. G-C forms 3. As the strands bond they hold the Base Pairs of DNA together
Evolution is the theory of slow change during long time periods.
Answer:
In humans, the major precursors from which glucose can be synthesized from are:
1. glycerol from triacylglycerols
2. glucogenic amino acids from protein.
3. Oxaloacetate formed from CO2
4. Pyruvate foem pyruvate carboxykinase
All there's are routes through which the body obtains glucose to replenish body glucose levels
Parasite: Parasites are different from predators because parasites only take resources from one host, whereas predators eat many prey. A good example of this is the trematode parasite Schistosoma mansoni. An adult schistosome parasite lives inside of just one human host
The answer is stabilizing selection.
<span>Sickle-cell anemia is a recessive disorder caused by the presence of two recessive alleles "s", so genotype is "ss". This disorder is characterized by sickle hemoglobin. In an area with malaria, heterozygous individuals "Ss" (with one dominant allele and one recessive allele) have an advantage. These individuals will have both normal and sickle hemoglobin. But pathogen that causes malaria affect only normal hemoglobin, so heterozygous individuals will have half of the hemoglobin resistant to the pathogen and those individuals are resistant to malaria.</span>
Stabilizing selection favors heterozygotes Ss, disruptive selection favors dominant (SS) and recessive (ss) homozygotes, while directional selection favors dominant (SS) or recessive (ss) homozygote. Since in this example, people with genotype Ss (heterozygotes) are in advantage, then this is an example of stabilizing selection.
