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.
Answer:
D. Gross primary productivity is the total amount of solar energy captured by producers through photosynthesis over time.
Explanation:
The gross primary productivity of an ecosystem represents the rate at which the producers of the system capture the solar energy so that they can perform the process of photosynthesis. Therefore, GPP is the total amount of photosynthetic energy captured per unit area over a given time period. Producers consume the part of the GPP for their own respiration and maintenance. Therefore, gross primary productivity is the sum total of the growth of producers per unit area per unit time and the energy used by them for respiration.
Answer:
- Diploid → Prophase, metaphase, and anaphase
- Haploid → Telophase
Explanation:
During prophase I, chromosomes get condensed. Each of the chromosomes gets in pair with its homologous one. They do so to make the crossing-over possible, a stage where they interchange their parts → 2n
During metaphase I, each of the homologous pairs is driven to the equatorial plane, where they randomly line up → 2n
During anaphase I, occurs the independent separation of homologous chromosomes that migrate to opposite poles of the cell. This separation generates different chromosomal combinations in the daughter cells. There are two alternatives per homologous pair → 2n
In telophase I, half of the chromosomes are already in one of the poles, while the other half is on the other pole. Each group of chromosomes has now half the number of the original cell. The nuclear membrane forms again in each pole → n
Finally, occurs cytokinesis, which involves the invagination of the cell membrane and cytoplasmic division.
The two new cells are ready for meiosis II.
E. beef liver
none of these foods have cholesterol, in fact avocado can help lower cholesterol.
Actually, all four of them are correct. Bacteria are responsible for all of them and they are very important.
