Answer:
Cilia and flagella are projections from the cell. They are made up of microtubules , as shown in this cartoon and are covered by an extension of the plasma membrane. They are motile and designed either to move the cell itself or to move substances over or around the cell.
Explanation:
Answer: The temperature of the rainforest does not experience a drastic fall as in the case of the desert.
Explanation:
In the desert the average daytime temperature remains 100°F and that of the rainforest is 85°F. But average monthly temperatures are lower in the case of desert as compared to the rainforest although the vegetation cover is higher in rainforest as compared to desert so humidity is also more. During night in desert temperature drops to an average of 25°F whereas in rainforest during night temperature level does not drop much it drops to only 71°F. Therefore, the average monthly temperature on desert is lower than rainforest.
Answer:
The mentioned characteristics of variability are witnessed because of the phenomenon known as X chromosome inactivation in heterozygous females. As females possess two X chromosomes, they actually should not possess any color blindness.
The phenomenon of X-chromosome inactivation takes place in a random manner at the time of embryo development. During this only one X chromosome is inactivated. If the chromosome comprising the defective gene is inactivated, the individual will possess normal vision.
If the chromosome comprising the usual gene gets inactivated than the individual will be color blind. In the given case of female, X inactivation took place in one eye. The inactivation of normal alleles has taken place and thus she possesses normal vision with one eye and is color blind in the other eye.
Answer:
Natural selection or genetic drift
Explanation:
Natural selection and genetic drift are two different evolutionary mechanisms that can lead to speciation. This is, to the origin of two species from a single species (the common ancestor).
Allopatric speciation is a type of speciation where emerging species arise after an ancestral population is divided by a geographical barrier preventing contact and therefore gene flow between individuals of split populations. The split populations eventually could become new species.
Natural selection occurs when the split populations changes genetically due to environmental pressures. The genetic drift occurs when the genetic changes are due to random sampling of organisms.
