Answer:
A
Explanation:
As the species seperated they formed a differnt beak based on what they ate.
A biological system is a complex network of biologically relevant entities. ... Examples of biological systems at the macro scale are populations of organisms. On the organ and tissue scale in mammals and other animals, examples include the circulatory system, the respiratory system, and the nervous system. source: google
Answer:
a structure composed of several proteins that associate with the centromere region of a chromosome and that can bind to spindle microtubules
Explanation:
Kinetochores have vvery important role in the cell division-mitosis.
During the metaphase of mitosis, spindle fibers attach to kinetochores. Some of the microtubules bind to kinetochore (kinetochore microtubules) while other don’t: they connect with the microtubules from the opposite pole, stabilizing the spindle.
During the anaphase, kinetochore microtubules pull chromosomes toward poles, helping the sister chromatids separate from each other.
Answer:
secrete a cytokine that triggers apoptosis
Explanation:
Cytotoxic T cells secrete granzymes and perforins when targeting cells. Additionally they secrete cytokines such as IFN-, TNF-α and TNF-β that act to activate macrophages and help kill infected cells.
Answer:
Lignin is found in plant cell wall, particularly in middle lamella of cell wall (eg. sclerenchyma tissue).
<u>Role of lignin in plants:-</u>
- It helps in conduction of water.
- It provides mechanical support to the plant.
- It also nurtures resistance to many kinds of stress.