Answer:
Sonic Hedgehog.
Explanation:
Sonic hedgehog is a secreted protein that in humans is encoded by the SHH gene. It is the best studied ligand of the hedgehog signaling pathway, others being desert hedgehog (DHH) and Indian hedgehog (IHH). It plays a key role in the development of animals, from insects to mammals. In vertebrates, it is involved in organogenesis, including the growth of digits on limbs and the organization of the brain.
Sonic hedgehog has also been shown to act as an axonal guidance cue. It has been demonstrated that SHH attracts commissural axons at the ventral midline of the developing spinal cord. Specifically, SHH attracts retinal ganglion cell (RGC) axons at low concentrations and repels them at higher concentrations
Answer:
C. The chance of survival decreases when there is intraspecific competition for resources among surviving yearlings
Explanation:
The survival rate of the offspring of the fish species will decrease as a result of the huge number of eggs produced giving rise to overpopulation. Pressure will be on the limited available resources. As a result of this, Intraspecific competition would occur as members of the same fish species would compete for the limited resources.
Interference and exploitation competition are two types of Intraspecific competition that can reduce the population size of the fish species.
For Interference competition, the dominant and stronger members would secure adequate supply of the limited resources to detriment of the weaker and less dominant ones. This leads to the death of those members that are weak to compete successfully, thereby leading to a reduction in population size.
In exploitation competition, it involves all individual members of the fish species sharing the limited resources equally, while none of them gets an adequate amount. With time, a great size of the population decrease would be noticed when compared to that of Interference competition.
Answer:
The progeny produced is 100% heterozygous individuals.
Explanation:
Remember that in Mendel crosses, there are two alleles for each character, in this case for the color of the flowers.
When the problem refers to pure varieties, it refers to individuals with two equal alleles for the same gene.
If two pure varieties with antagonistic characters intersect, 100% of heterozygous individuals will be obtained in the offspring.
As for its phenotype, it will depend on which allele is dominant over the other.
The answer is the platelets
There are many environmental negative direct outcomes of unused excess nitrogen from nitrogenous fertilizers. One of these is eutrophication. Eutrophication is the excessive richness of nutrients in a water body as a result of fertilizer run offs from the land, which causes a dense growth of plants in the water. Other negative outcomes are: green house effects, acid rain and contamination of underground water which has negative effects on human health.
