Answer:
D
Explanation:
Bone marrow contains stems cells which then turn into immature blood cells and they mature there. kinda like a school for young blood cells. they also make white blood cells and platelets.
Natural gas
explanation:
solar power, coal, and petroleum are used to power things (i.e. produce electricity)
Answer:
Cas9-sgRNA cannot align with targeted DNA sequence
Explanation:
Without a PAM sequence, the CRISPR-sgRNA (small guide RNA) complex cannot align with the targeted DNA sequence. Therefore, you cannot perform experiments (e.g. gene editing) using CRISPR-Cas9.
D, because skin tans to help us stand being in the sun without getting burned.
An example of physiological adaption is being able to digest milk. Before, humans were not able to digest milk before we developed enzymes that now make us have the ability to do so, thus allowing us another food source.