A cell wall is a structural layer that surrounds some types of cells, situated outside the cell membrane. It can be tough, flexible, and sometimes rigid. It provides cells with both structural support and protection, and also acts as a filtering mechanism. Cell walls are present in plants, fungi and prokaryotic cells, where a major function is to act as pressure vessels, preventing over-expansion when water enters the cells. Cell walls are absent from mycoplasmas.
Answer:
D. The threat of predators to eat eggs
Explanation:
The internal gestation followed by live birth was an adaptation developed by the mammals on land, and by some fish in the water, like the sharks. The mammals have been the most marking ones in this adaptation though. They too were producing eggs initially, but because they were living in an environment where there were numerous animals that preyed upon them, as well as their eggs, they had to be innovative. They developed internal gestation, where the embryo was developing inside the body of the female, and then it was born alive. This was providing extra safety, as the embryo was always with the mother, instead of being left alone and not guarded, thus an easy meal for the predators. The two types of internal gestation that the mammals developed are the placental and marsupial types, with the placental turning out to be more successful over time.
"Positive feedback mechanisms lead to increased change" is the statement about <span>positive feedback mechanisms </span>among the choices given in the question that is not true. he correct option among all the options that are given in the question is the third option or option "c". I hope the answer has helped you.
It was probably an Animal cell
