Answer:
(B) Energy transfer between trophic levels is almost always less than 20% efficient.
Explanation:
The ultimate source of energy on the Earth is the Sun. The energy coming from the Sun is captured by green plants by the photosynthesis. During photosynthesis sun energy is fixed into chemical energy (carbohydrate). So, in an ecosystem energy flow is unidirectional (from sun to the green plants). The fixed chemical energy from green plants is transferred to the herbivores then to carnivores through food. When one organism eats another organisms, only 10 % of the energy present in the organism is transferred as a food for the next organism and a large amount of energy is lost as heat into the environment. Thus, energy keeps on decreasing when stored energy moves from producers to top consumers. Thus, less than 20% energy transfer limits the trophic levels in most of the ecosystem.
Answer:
(2) low power: 100 small pollen grains
high power: 25 large pollen grains
Explanation:
Compound light microscopes are devices used to greatly magnify objects. They have several objective lenses, a low-power lens magnifies 10 times (10X) the objects, and the high-power lens magnifies them 40 times (40X).
For that reason, when observing the pollen grains with the high-power lens the student will see them bigger than with the low-power lens. However, the field of view (the visible area through a lens) is reduced when a higher power lens is used, so fewer pollen grains will be seen.
The answer therefore is the option of higher number of pollen grains of small size for the low-power lens, and lower number of pollen grains of larger size for the high-power lens.
The plant wilted as the salt absorbed all the water in the large vacuole. For which it shrunk making the plant wilt
Sample Response: This theme is universal. It can apply to all people, and most people struggle with this question.
