Answer:
A.) Alligators have round snouts, while crocodiles have pointed, V-shaped snouts.
Explanation:
The difference in crocodiles and alligators is in their snouts.
Answer:
1. Signaling molecule
2. Signaling receptors
Explanation:
Hormones, growth factors, neurotransmitters, etc. serve the function of signaling molecules for cells. These molecules are released by one cell and bind to the receptors present on/in the target cells to elicit the desired response. Thereby, the signaling molecules serve in cell-cell communication.
For example, insulin hormone synthesized and released from beta cells of pancreas binds to its cell surface receptors present on the surfaces of liver cells and muscle cells to stimulate the uptake of the glucose from the blood.
Likewise, neurotransmitters released from the presynaptic neuron bind to receptors present on the membrane of postsynaptic neuron and serve to carry the nerve impulse to the postsynaptic neuron.
The walls of xylem cells are lignified (strengthened with a substance called lignin ). This allows the xylem to withstand pressure changes as water moves through the plant.
The cell membrane is flexible because of the presence of oil like substances called phospholipids, which gives it a fluid nature. While as the cell walls are rigid because of the presence of the thick layers of the substances like cellulose in plants, chitin in fungi and peptidoglycon in bacteria.
Answer:
Dune vegetation would miss a significant source of nutrients if sea turtles go extinct and would not be as stable and not large enough to support the dunes, resulting in increased erosion.
Explanation:
While their range is wide, due to extensive egg collecting and bycatch fisheries, the numbers of leatherback turtles have decreased dramatically over the past century.
