D is the correct answer. Hope this helps.
Answer:Capillaries
Explanation: Capillaries are tiny, thin walled vessels that form a network to take blood through the organs and other body tissues. The dense networks of capillaries present a large surface area, which allows materials to be exchanged between body cells and the blood rapidly.
<h3><u>Answer</u>;</h3>
Key
A sorting device that is useful in classifying by observation is a <u>key</u>.
<h3><u>Explanation</u>;</h3>
- <em><u>Classification key or taxonomic key is a device that is used by scientists to identify unknown organisms. </u></em>
- They are constructed so that the user gets a series of choices about the characteristics of the unknown organisms.Thus, by making the correct choice at each step, one is led to the identity of the specimen.
- Therefore<u><em>, keys can be used to identify a living organism or determine which group it belongs to</em></u> by answering questions on the key about characteristics of living things.
Answer:
they may "loop out" of the cell cycle and into a resting state called G0, from which they may subsequently re-enter G1 under the appropriate conditions
Explanation:
At the G1 checkpoint, cells decide whether or not to proceed with division based on factors such as: Cell size
