Answer:
The correct answers would be natural selection and high genetic variation in the species.
Natural selection refers to the natural phenomenon by which organisms which are better adapted or have survival traits tend to survive and reproduce more in the environment.
It leads to an increase in the frequency of the trait in a population.
Genetic variation refers to the sum total of all the genetic characteristics present in a population. Higher genetic diversity higher are the chances of a population to survive.
Similarly, different sizes of the beaks are the result of high genetic diversity out of which large size beak was favored by natural selection.
Ultimately, the large beak size trait spreads through the population.
Because some music is more rare to find than others.
Answer:
Karl Landsteiner along with his coworkers recognized four types of blood groups in human beings, commonly called as ABO blood grouping.
Explanation:
The membrane of RBCs possess several antigens. Depending on the nature of antigens on the surface of RBCS various types of blood grouping has been done. Two such groupings are The ABO and Rh grouping and are widely used all over the world.
ABO grouping:
There are four types of blood groups in human beings. ABO grouping is based on the presence or absence of two surface antigens on the RBCs namely A and B. Similarly, the plasma of different individuals also contain two natural antibodies called anti-A and anti-B.
If an antigen is present on the surface of RBCs, the corresponding antibody must be absent from the plasma and if the antigen is absent on the RBCs, the corresponding antibody must be present in the plasma.
Blood group A has A antigen on RBCs and anti-B antibody in plasma
Blood group B has B antigen on RBCs and anti-A antibody in plasma
Blood group AB has A and B antigen on RBCs and no antibody in plasma
Blood group O has no antigen on RBCs and both anti-A and anti-B antibody in plasma
Rh grouping:
Another group of antigens found on the RBCs of most people is the Rh factor. People who have this antigens are said to be Rh+ve whereas those who do not are called Rh-ve. Rh groups should also be matched before transfusion because A Rh-ve person if exposed to Rh+ve blood , will form specific antibodies against the Rh antigen.
Answer:
The answers are B and D.
Explanation:
The co-evolution of plants and insects led to an increase in both populations due to the mutualist benefit of this relationship. As plants started to develop rewards for the insects (such as pollen and nectar) the insects started to be able to travel further and therefore colonize, then as diversification of flowers began, also the insects started to diversify in order to afford the vast amount of food for them. Insects helped plants to pollinate and plants helped insects to spread. But as insects were evolving, some mammals and birds were also doing so, therefore, plants developed fruits with seeds in order to increase their dispersal. As answer D exposes, animals not only enhanced pollination but they also provided seed dispersal.