An organ or group of specialized cells in the body that produces and secretes a specific substance, such as a hormone
Answer:
convergent evolution
Explanation:
If we have two species that share a similar trait or look alike a lot, but they live in places isolated from each other, and they only have a very distant relation, then it is a case of convergent evolution. This type of evolution occurs with species that are not closely related, but they live in environments where having the same or very similar traits is advantageous. This can often lead to a confusion when looking at the species only on the outside, and it can be very misleading. As an example we can take the sabretoothed predators that existed in the past. Both the smiloden and the thylacosmilus had large saber like teeth, and even their bodies looked very similar, so one would assume that they are closely related, but that was not the case. The smilodon was part of the cat family, while the thylacosmilus was a marsupial, making them very distantly related. They developed same same and some very similar traits because their environment created the evolutionary pressure for those traits to develop as they were advantageous, despite them evolving in totally different places and separately.
Answer:
The correct answer is A) Have diverse cell wall compositions
Explanation:
Both bacteria and archaea comes under prokaryotes because they both lack a membrane-bound nucleus. The difference between archaea and bacteria is in their cell wall composition.
The bacterial cell wall is made up of peptidoglycan and the archeal cell wall is made up of pseudo-peptidoglycan. In bacteria, peptidoglycan contains N acetyl muramic acid and N acetyl glucosamine unit but in archaea, the N acetyl muramic unit is replaced by some other unit and the linkage of two units is also different in archaea. So the right answer is A.
Rainforest cover only 2 % of the total surface area of the Earth but in spite of that about 50 % of plants and animals that live on the Earth live there.
By definition rainforests are forests that recieve high amounts of rainfall so you can actually find rainforests in Alaska for example (other examples: Canada, Asia, Africa, Latin and South-America)
About 1/4 of natural medicines are found in rainforests. 70 % or more of the plants that are used to treat cancer are found only in tropical rainforest on the planet.
Trees in tropical rainforests are so dense that it takes approximately 10 min for the rainfall to reach the ground from canopy.
Answer:
Variation can be acted on by natural selection.
Explanation:
Variation are the difference that exist in the organism in terms of the body size and can be acted upon by natural selection.
Natural selection could act on the owl body size, favor the selection of owl with small body size especially when resources available are limited and can only sustain small number of individuals leading to availability of owl with small body size in such area and a gradual reduction in the number of owl with large body size.
