Crossing over occurs at the four-strand stage when two homologous chromosomes, each consisting of a pair of sister chromatids, are paired. Each crossover involves just two of the four strands and generates two recombinant strands.
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<span>Answer:
Passive aggressive communication avoids honest, direct communication and expresses her concerns to others in an attempt to make other people look bad.</span>
Answer:
there are 4: paracrine signaling, autocrine signaling, endocrine signaling, and synaptic signaling
Explanation:
paracrine:cells that are near one another communicate through the release of chemical messengers
autocrine: a cell signals to itself, releasing a ligand that binds to receptors on its own surface
endocrine:When cells need to transmit signals over long distances, they often use the circulatory system as a distribution network for the messages they send.
synaptic: nerve cells transmit signals. The junction between two nerve cells where signal transmission occurs.
D oxygen there was no free oxygen on the earth
Lipids have no polymers.
A lipid is formed when a glyceral combines with one or more fatty acids.
