<h2>Vasa recta </h2>
Explanation:
The vasa recta is a specialized capillary that branches from the efferent arteriole; The blood flow in the vasa recta runs parallel, but in the opposite direction to the flow of tubular filtrate within the nephron loop
- The vasa recta capillaries are long, hairpin-shaped blood vessels that run parallel to the loops of Henle
- The hairpin turns slow the rate of blood flow, which helps maintain the osmotic gradient required for water reabsorption
- Absorbed water is returned to the circulatory system via the vasa recta, which surrounds the tips of the loops of Henle
- Because the blood flow through these capillaries is very slow, any solutes that are reabsorbed into the bloodstream have time to diffuse back into the interstitial fluid, which maintains the solute concentration gradient in the medulla; this passive process is known as counter-current exchange
Nuclear Fission is when a large nucleus splits into two smaller nuclei with the release of energy. In other words, fission the process in which a nucleus is divided into two or more fragments, and neutrons and energy are released.
The set of reactions that is the primary route of ATP production in the cells is called ETS REACTIONS. ETS stands for Electron Transport System. The reactions occur in the cristae of the mitochondria in the presence of cytochromes and coenzymes, which act as carrier molecules. They accept energized electrons and pass the electrons to the next molecules in the system. The overall reaction result in the production of ATP, which is the only form of energy that is usable by the cells.
Answer:
AaBb × aabb
Explanation:
A test cross is a cross between an unknown genotype (dominant phenotype) with a homozygous recessive genotype in order to discover the actual genotype of the species exhibiting dominant phenotype.
This is because one allele of a gene is capable of masking the expression of another, the allele masking is called DOMINANT allele while the allele being masked is called RECESSIVE allele. The combination of these two alleles is termed heterozygosity.
An organism that is phenotypically dominant for a specific trait may either be heterozygous or homozygous for that gene. For example, a plant gene for tallness with an dominant allele T, and recessive allele t. This plant will need tall if the genotype is TT (homozygous dominant) or Tt (heterozygous dominant). In order to know which of these genotypes the plant actually has, a test cross is conducted.
In this example, two genes A and B are involved. For the first gene, A represents dominant allele while a represents recessive allele. For the second gene, B represents dominant allele while b represents recessive allele.
In a cross involving parents AABB (homozygous dominant for both genes) and aabb (homozygous recessive for both genes), the F1 progeny will all exhibit phenotypic dominance (AaBb).
However, we cannot know the genotype by merely looking at the phenotype. We cannot ascertain yet whether the dominance is heterozygous or homozygous, hence the need for a test cross.
The test cross is between the dominant F1 progeny and a homozygous recessive i.e. AaBb × aabb. Some of the F2 generation will show recessive traits if the unknown genotype is heterozygous.
