D: needs to be present on both chromosomes to be expressed
Why: Because if there was a dominant trait present, then the dominant trait would overpower the recessive trait regardless of the matter.
The temperature and salinity affect deep water current since
The water density depends on temperature and salinity . The deep currents from where the density of ocean water increases. The decrease of the temperature of water led to increase in water salinity while the density of water also increases.
Answer:
B is true .. atmosphere always changes day by day
Answer:
Both fish and bird embryos exhibit gill slits and a tail.
Explanation:
According to embryology, all vertebrates exhibit similar traits and structures at their embryonic stage. It becomes very difficult to differentiate between the embryos of a fish, and that of a bird, or embryo of a fish, and a human. These traits, however, disappear, as the case may be, as the embryo develops into an adult. For example, in the case of the embryo of a fish, and a bird, both shows gills slits at their respective embryonic stage. However, the gill slits in fish develop into gills, whereas in the case of birds, it disappears as the embryo develops into an adult.
Natural selection and speciation: 'Ecological speciation'. ... Natural selection is generally recognized as a central mechanism of evolutionary change within species. Thus, natural selection plays a major role in generating the array of phenotypic and genetic diversity observed in nature.
