A staple food<span> is one that is eaten regularly and in such quantities as to constitute the dominant part of the diet and supply a major proportion of energy and nutrient needs. ... Just 15 </span>crop<span> plants provide 90 percent of the world's </span>food<span> energy intake, with three rice, </span>maize<span> and wheat - making up two-thirds of this.</span>
Answer:
B) oaks and other sexually reproducing, extant (currently living) trees
Explanation:
The biological species concept defines the species on the basis of their reproductive isolation. It states that when individuals are able to interbreed to produce fertile and viable progeny, they belong to the same species. The members of different biological species cannot interbreed. If they interbreed, either pre-zygotic or post-zygotic isolation mechanisms do not allow the production of fertile progeny.
Therefore, the biological species concept can be applied to the organisms that are able to reproduce sexually. The asexually reproducing organisms would not exhibit any reproductive isolation which is a key criterion to group organisms under different species. Among the given examples, biological species concept can be applied to the sexually reproducing extant trees such as oak.
Since we cannot deduce the reproductive isolation in sexually reproducing extinct species, the concept is not useful for dinosaurs which are extinct now.
Tha main components in blood are the plasma, red blood cells, white blood cells, and blood platelets.
Plasma is like the main component that makes up most of the blood. It has a light yellow color and it carries many substances including nutrients, waste, hormones and more.
Red blood cells are the reason why blood is red in color. They have a hemoglobin inside them which can help carry oxygen for the tissues and organs. In order to maximize the oxygen carrying capacity, they don't have a nucleus.
White blood cells can be divided into phagocytes and lymphocytes. Their main function is to protect us from diseases. Phahocytes and engulf and digest bacteria, while lymphocytes can produce antibodies.
Blood platelets can cause blood clotting which can stop us from bleeding forever. They're not cells, but just fragments of cells. They also don't have nucleus since they're not complete cells.
Little Rock is right in the middle of the state so to figure out where the storm will go next you need the direction of the wind
Answer: a specific protein
Explanation: