The right answer is D (less responsive to antigens)
It is proven that, after puberty, thymus activity (an organ that is included in the lymphatic system, producing T cells that pick up antigens) decreases and that in adult and aged people the thymus has no role. Work done in humans indicate that in fact the cellularity begins to decline from birth in favor of lymphocyte perivascular spaces and connective and adipose tissue, which leads to a decrease in the capture of antigens.
Viral replication involves six steps: attachment, penetration, uncoating, replication, assembly, and release. During attachment and penetration, the virus attaches itself to a host cell and injects its genetic material into it.
toxic enzymes that damage the host cell that are coded for in the viral genome
secretion of chemicals from the virus to the membrane of the host cell
replication of the viral genetic material within the host
lysis of the host to release new viruses
integrating into the host cell chromosomes
Answer:
Vascular Tissues
Explanation:
Angiosperms higher flowering plants it is most diverse group in a plant kingdom nearly 300,000 species of flowering plants are found under this kingdom.The angiosperms have specialised cells and tissues that carry out their metabolic functions and evolved vascular tissues (xylem and phloem) that translocate the water and nutrient to all parts of the plant. They are terrestrial, root system absorbs water and mineral from the soil. the shoot system supports and leaves involved in the process of photosynthesis
