Answer:
C. antigen-antibody reactions
Explanation:
human blood group is determined by the presence of antigens on the red blood cells which are specific proteins.
so specific antibodies are used against these antigens to determine the type of blood group after the reaction.
Some mutations in living species help them to adapt and help protect them from predtors
the difference between the birth rate nad the death rate is known as growth rate. the growth rate is expresse in percentage ex:the presentrate of india is 1.93% per annum . According to 2001 census, birth rate was 26.1 per thousand and death rate was 8.7 per thousand . thus growth rate was 19.3 or 1.93% per year . births and death continue to take place at all places around the world . the differnce between total birth and total birth and total deaths in a populations over a period of time decides whether the population growthof the place is positive or negative. if the birth rate is higher than the death rate in a country, it means that the population will register a growth on the other hand, birth rate less than death rate indicates a shrinking population
I believe the answer is the Plateau phase of the sexual response cycle. The sexual response cycle has four stages of sexual responding described by Maters and Johnson; that is the excitement, plateau, orgasm, resolution phases. During the excitement phase, the genital areas become engorged with blood. During the orgasm phase, there are muscle contractions all over the body, further increasing breathing, pulse and blood pressure rates; and during resolution phase the body gradually returns to its unaroused state as the engorged genital blood vessels release accumulated blood.
