Answer:
Let's recall Mendel's law of independent assortment that states, "During the formation of gametes, alleles of genes assort independently into each gamete"
How can the random distribution of alleles result in a predictable ratio?
For example, We have a trait for flower color either yellow or white, and the alleles for the flower color are Y and y. The yellow flower color is a dominant trait, and be expressed if plant has YY or Yy genotype. We cross a plant with genotype Yy with another plant Yy.
P1 Yy x Yy
F1 YY : Yy: Yy: yy
Phenotype Yellow: yellow: yellow: white
Genotypic ratio 1 : 2 : 1
Phenotypic ratio 3 : 1
So, we see that phenotypic ratio is different from genotypic ratio. Although the distribution of alleles is random but still there are only four possible outcomes for a trait. Hence, we can predict the phenotypic and genotypic ratio of offspring by drawing a punnet square or gamete formation.
Answer:
Uracil "U"
Explanation:
RNA shares Adenine (‘A’), Guanine (‘G’) and Cytosine (‘C’) with DNA, but contains Uracil (‘U’) rather than Thymine.
Answer:
d. FGF2 signaling, splanchnic mesoderm
Explanation:
Hemangioblasts are the cells that serve as common precursors for blood vessels and blood cells. The hemangioblasts develop from mesenchyme and can give rise to angioblasts (to serve as precursor cells for blood vessels) or pluripotent stem cells to serve as a precursor for blood cells.
The basic fibroblast growth factor (FGF2) is one of the three factors required for initiation of formation of blood vessels. The basic fibroblast growth factor (FGF2) is required for the development of hemangioblasts from the splanchnic mesoderm and their differentiation into angioblasts.
