After the macrophage fails the Helper T Cell stimulates the B cells (create antibodies) if pathogen is extracellular and Cytotoxic T Cells (killer T cells, release perforin) if pathogen is intracellular. Once the pathogen is killed the B Cells create Memory B Cells and the Killer T Cells create memory T Cells.
<span>Hope that's helpful.</span>
Answer:
Heyy I hope this helps!! Bread for sure is a Carbohydrate!
The answer is (A) Mitochondria have their own DNA molecules, separate from the rest of the cell's DNA.
The endosymbiotic hypothesis concerns with the presence of two special organelles, mitochondria and chloroplast within the eukaryotic cell. These two organelles have their own set of DNA that is different from the nuclear DNA of the eukaryotic cell. It is believed that a primordial eukaryotic cell was in a symbiotic relationship with mitochondria-like bacterium. The primordial cell eventually engulfed the mitochondria-like bacterium for ATP production to power itself.
I believe that a pair of homologous structures in this case is; Maple leaf and oak leaf. Homologous structures that have similar ancestries and common traits, however they may not have the same function in an organism. They appear in different animals or organisms, underlining anatomical commonalities demonstrating a descent from a common ancestor. Examples include the arm of a human, the wing of a bird or a bat, the leg of a dog and the flipper of a dolphin or whale.
