Contour: Gives the bird its stream line shape.
<span>Down feathers: Keeps the bird warm.</span>
A physical factor that influences an ecosystem is called an "abiotic factor."
Answer:
<u>d. the cells in primary cell cultures do not divide.</u>
A key difference between primary cell cultures and secondary cell lines is that<u> the cells in primary cell cultures do not divide.</u>
<u>hope</u><u> </u><u>it</u><u> </u><u>helped</u><u> </u><u>you</u><u> </u>
Explanation:
<em>The main difference between primary and secondary cell culture is that the primary cell culture contains the cells directly obtained from host tissue, whereas the secondary cell culture contains sub-cultured cells from primary cell culture.</em>
The hydrosphere i believe, hope this helps!