Answer:But Earth's distance from the sun doesn't change enough to cause seasonal differences. Instead, our seasons change because Earth tilts on its axis, and the angle of tilt causes the Northern and Southern Hemispheres to trade places throughout the year in receiving the sun's light and warmth most directly.Sep 23, 2019
Explanation:
The Hertzsprung-Russell diagram is one of the most important tools in the study of stellar evolution. Developed independently in the early 1900's by Ejnar Hertzsprung and Henry Norris Russell, it plots the temperature of stars against their luminosity (the theoretical HR diagram), or the color of stars against their absolute magnitude
Depending on its initial mass, every star goes through specific evolutionary stages dictated by its internal structure and how it produces energy. Each of these stages corresponds to a change in the temperature and luminosity of the star, which can be seen to move to different regions on the HR diagram as it evolves. This reveals the true power of the HR diagram – astronomers can know a star’s internal structure and evolutionary stage simply by determining its position in the diagram.
The Hertzsprung-Russell diagram the various stages of stellar evolution. By far the most prominent feature is the main sequence (grey), which runs from the upper left (hot, luminous stars) to the bottom right (cool, faint stars) of the diagram. The giant branch and supergiant stars lie above the main sequence, and white dwarfs are found below it.
Answer:
25%
Explanation:
Let's assume that the recessive allele "p" imparts diseased conditions in the homozygous genotypes. The genotype of each of the carrier parents would be "Pp". A cross between Pp and Pp would produce progeny in the following phenotype ratio=
Pp x Pp= 3/4 Normal : 1/4 Affected.
Therefore, there are 1/4 or 25% chances for this couple to have a child with PKU.
A b c d e f g h i j wow sir
<span>The answer is B. The number of stomata is more on the lower surface of the leaf. Carbon dioxide enters the leaves through the stomata. In the leaves, it is used in the photosynthesis and converted into oxygen and glucose. Since the energy of Sunlight is important for the photosynthesis, stomata must be opened during the day. So, to avoid direct Sunlight and thus cause leaves dehydration, the number of stomata is more on the lower surface of the leaf.</span>
