Answer: (B) Pre-zygotic; post-zygotic.
Explanation:
Prezygotic isolation occurs before fertilization of eggs. It occurs between the two sex gametes and deter sexual reproduction between different species.
However, individuals are considered to be diverge on the phylogeny tree and different species, when they cannot reproduce.
Mechanisms of prezygotic isolation include habitat isolation, gamete isolation, mechanical isolation, behavioral isolation, and mating seasons.
Whereas, postzygotic isolation prevents the formation of fertile offspring. This phenomenon leads to production of an hybrid offspring from different species and this is a form of speciation in nature.
Mechanisms of postzygotic isolation include hybrid inviability, hybrid breakdown, and hybrid sterility.
True because the surface of the water table may vary due to seasonal change
Carbohydrates
Carbohydrates are a type of nutrient are found in many foods including: fruits, vegetables, cereals, grains and sweets. Carbohydrates serve as a fuel, providing us with energy and playing a role in brain and organ functioning. Carbohydrates also provide fiber, that is important for excretory functions. There are many types of carbohydrates that have different effects on the body, such as: simple carbohydrates, complex carbohydrates, sucrose, fructose, lactose, etc.
<span>Anton van Leeuwenhoek learned to grind lenses ( 1668) and develop simple microscopes.
</span>
Leeuwenhoek heated the middle of a small soda glass rod , over a flame. On pulling apart the two ends, the glass rod elongated into thin whiskers .
Heating the end of this whisker resulted in a tiny high quality glass sphere. These glass spheres then became the lens of his microscope, with the smallest sphere providing the greatest magnification.
Leeuwenhoek's designs were very basic. The body of the microscope was a single lens mounted in a tiny hole on a brass plate. The specimen was then mounted on a sharp point that sticks up in front of the lens. It's position and focus could be adjusted by turning the two screws.
The entire instrument was about 3 to 4 inches long and had to be held up close to the eye, requiring good lighting and great patience to use.
Answer:
Your body sends a message to the lungs and tell the lungs to breathe in more oxygen so that the oxygenated blood can travel to the muscles oxygenating the cells within that specific muscle and giving them energy to use the sugars stored in fat or food from digestion. The heart beats faster so that the cells supply keeps up and continues to beat fast for that specific diration of time until your breathing slows down and it no longer needs to work as fast to supply the muscles with as much blood.