Answer:
D. In the tunica, cell divisions are parallel to the stem axis, giving rise to thick layers of tissues covering the inside of the tip.
Explanation:
For a reaction to occur, substrate particles need to collide with each other with enough force (To overcome activation energy), at the right orientation for a successful collision, causing a reaction to occur.
Enzyme catalysts are a type of protein that has a specific 3 dimensional conformation. They have specific reaction sites called active sites. Substrates collides with the enzyme and binds to the active site if it fits to the specific 3 dimensional conformation. This allows bonds to be either formed or broken for reactions to occur.
This process provides an alternative reaction pathway with lower activation energy to enable the rate of reaction to increase.
Biogeographical studies use information for various fields, such as evolutionary biology, geography, geology, and climate science to determine how organisms evolved through time and how the moving of tectonic plates resulting in forming continents, mountain ranges and islands has affected their distribution.
Studies in this field explain how organisms that now live on different continents are very closely related and how the flora and fauna of islands are connected to one of the closest continents etc.
Answer:
is a way for a cell to give information about its activities.
Explanation:
Antigen-presenting cells (APC) such as dendritic cells, macrophages, and B cells are present where antigens are most likely to penetrate the body. Ingestion of antigens by these cells is followed by digestion of antigen into peptide fragments and their association with MHC molecules.
The antigen-MHC complex is then inserted into the plasma membrane of APCs. The antigens present on the surface of APCs are recognized by the T cells to trigger the adaptive immune response. Antigen processing and antigen presentation by antigen-presenting cells are required to inform the T cells of the immune system about the presence of antigen in the body and immune responses of APCs.
