I think a villain can be a protagonist because the hero is antagonist.
Answer:
Layer A is the crust and Layer B is the mantle.
Answer:
Helper T cells are arguably the most important cells in adaptive immunity, as they are required for almost all adaptive immune responses. They not only help activate B cells to secrete antibodies and macrophages to destroy ingested microbes, but they also help activate cytotoxic T cells to kill infected target cells.
Explanation:
Helper T cells become activated when they are presented with peptide antigens by MHC class II molecules, which are expressed on the surface of antigen-presenting cells (APCs). Once activated, they divide rapidly and secrete cytokines that regulate or assist the immune response.
The right answer is Ribosomes
The ribosome is a complex composed of RNA and ribosomal proteins, associated with a membrane (in the granular endoplasmic reticulum) or free in the cytoplasm. Common to all cells (prokaryotes and eukaryotes), the ribosome (and especially its composition) varies according to the organisms, even if it is always composed of two distinct subunits.
The ribosome is a huge ribonucleoprotein complex that allows the translation of mRNAs into proteins.
Answer:
C. They have a greater surface-to-volume ratio.
Explanation:
Because these smaller cells can access and pass through the membranes of the other cell membranes and permeable coverings easily and voluntarily unlike larger cells. It is also efficient for these smaller cells to penetrate and travel, delivering and transporting goods and materials such as nutrients, oxygen and waste throughout the body without consuming enough energy and conserving lesser space.
For simple reasons, they are faster, more efficient and consumes little space, and most especially depletes lesser energy. So, many small cells have more surface area than one large cell.
