<span>A. abiotic component</span>
An ecosystem involves both the biological (plants, animals, human beings) and non-biological (land, water, soil, and atmosphere) community which interacts as a system. More importantly, the living things are very dependent on the abiotic community since it cannot survive by itself. Every animal, plant and human needs the primary physiological needs of water, food and shelter provided by the abiotic system.
Answer:
a. Type O blood - No A or B antigens on RBCs-Anti-A antibodies in plasma-Anti-B antibodies in plasma
b. Type A blood - A antigen on RBCs- Anti-B antibodies in plasma
c. Type B blood - B antigen on RBCs- Anti-A antibodies in plasma
d. Type AB blood - A antigen on RBCs- B antigen on RBCs- Neither anti-A or anti-B in plasma
Explanation:
ABO blood grouping system represents multiple allelism which was discovered in humans by Karl Landsteiner. The blood group is determined by the presence or absence of A & B antigens and antibodies.
The 4 blood groups which exist in ABO system are O, A, B and AB. Also, allele A and B are co-dominant i.e. if they both will exist on the surface of an RBC then both will be equally expressed which implies that there will be no dominant or recessive allele.
Type O blood group has H antigen on the surface of RBC and has both the antibodies i.e. antibody A and B. The absence of antigens A and B makes it a universal donor.
Type A blood group has A antigen on RBC and has antibody B in the plasma.
Type B blood group has B antigen on RBC and has antibody A in the plasma.
Type AB blood group has both the antigens i.e. antigen A and B on RBC and does not have any antibody in the plasma which makes it a universal acceptor.
It is generally followed by cytokinesis which divides the cytoplasm and cell membrane
Answer:
Methotrexate inhibits the synthesis of DNA, RNA, and protein synthesis of the cells in the experiment.
Explanation:
Methotrexate competitively inhibits the enzyme dihydrofolate reductase (DHFR) which is involved in the synthesis of tetrahydrofolate from the inactive dihydrofolate. The methotrexate blocks the enzyme by binding to its active site thereby preventing further reaction of the dihydrofolate reductase enzyme and dihydrofolate. Tetrahydrofolate is a useful material for the de novo synthesis of thymidine, a nucleoside. And without thymidine, DNA synthesis is hindered. Methotrexate therefore inhibits the synthesis of DNA, RNA, thymidylates and of course protein synthesis.
