Answer:
The correct answer is option A. "directional selection".
Explanation:
Directional selection is a type of natural selection at which traits with extreme characteristics are selected over traits with medium characteristics. In this case, a long-term climatic change resulted in all seeds that are the fountain of food for finch becoming hard. This will result in a directional selection on bill size in the finch population, where large-billed birds will be selected over small and medium-billed birds.
Answer: Antigens
Explanation: The ABO system of blood grouping is based on the basis of the type of antigens that are present in the red blood cells. Erythrocytes is another name for the red blood cells. Antigens are molecules that are capable of eliciting immune response. There are two types of antigens: antigen A and B. Blood type A has only antigen A, blood type B has only antigen B, blood type AB has both antigen A and B while blood type O has no antigen (neither A nor B antigen).
Similarly, Rh trait is determined by the presence or absence of rhesus antigen in the erythrocytes. Rhesus antigen is an antigen first discovered in rhesus monkey. Rh+ indicates the presence of rhesus antigen in the red blood cells while Rh- indicates the absence of rhesus antigen in the red blood cells.
Use environmental data from air, soil water,food and other materials for scientific analysis
The answer is <span>-Only the few bacteria that were immune to the antibiotic survived and reproduced, making all their offspring immune to it as well.
Bacteria (or any other organism) are not able to make changes to their DNA in order to protect themselves or to learn to remove the receptors on their cell surfaces. If they were able to produce toxins against the antibiotics, they would all survive.
These leave the second choice as the correct answer. This is the real situation, and is a good example of natural selection.</span>
A Hydrogen has a negative charge of -1 and o is positive and also neutral
