<u>Answer</u>: Natural selection.
<u>Explanation</u>:
- The concept of <em>natural selection</em> was given by <em>Charles Darwin.</em>
- According to this concept, in a given environment the organisms that possess <em>better adaptations</em> have<em> higher chances of survival</em> and, leave behind a <em>greater number of progenies</em>.
- When malaria outbreak occurs, the allele frequencies change and only the organisms that possess the alleles which help them to <em>survive</em> this outbreak due to resistance against malarial infection will be selected by nature and<em> hence, this is an example of natural selection.</em>
Answer:
a The pulmonary artery carries deoxygenated blood.
Explanation:
This is the the only artery that transports deoxygented blood in mammals. specifically it carry deoxgenated blood from the the atria to the pulmonary circulation. That is to the lungs for the exchange of the C02 in the deoxygenated blood with oxygen in the lungs.
The blood thus become oxygenated,and therefore return through the pulmonary veins to the left ventricle.
From the left ventricle ,through ventricular systole,blood is empty into the aorta through the aortic valves into the systemic circulation.
Although,they carry blood away from the heart,but the blood is de oxygenated instead of the usual oxygenated by arteries,They are still regarded as arteries because of convey of blood away from the heart,a typical role of arteries
Answer:
Its been used by humans to take the best traits from a species and pass them on like bigger bodies in cows for more meat and bigger muscles in horses for faster racing potential.
Answer:
A pollen tube grows from the pollen grain into the ovary
Explanation:
Water is needed for fertilization in several plant groups because the sperm needs to swim to meet the non-motile eggs of the female organs.
<em>However in angiosperms, the pollen germinates and a structure known as pollen tube which contains the male gametophyte (sperm) grows into the ovary where the ovule is located and the male gametophyte is deposited in the ovule to initiate the fertilization process.</em>
<em>Hence, water is really not necessary for fertilization in the angiosperms.</em>
Before assessing the two given cases, an assumption needs to be made about the digestion of the two types of food items, corn and beef. Let us assume that both get digested by expending same amount of energy by the human body. Let the amount of energy at producer level be an arbitrary X.
Case 1: Corn to human:
Since corn is at the producer level, it will have X amount of energy. The transfer of energy from corn to human will take place with a loss of 90% energy at the producer level. Hence the humans will receive 10% of X amount of energy.
Case 2: Corn to cow to human:
Since corn has X amount of energy, only 10% will pass to the next level, i.e. cow. So cow has 10% of X. Cow transfers only 10% of the energy that it has. Hence humans receive only 10% of 10% of X amount of energy.
It can be seen that humans receive more energy in case 1 than case 2. Hence we can say that it is more efficient for humans to feed on corn.
