Hydrogen<span>, </span>oxygen<span>, </span>nitrogen<span> and carbon. Does that help?</span>
Answer:
d.during only prophase I and involves exchange between chromatids of homologous chromosomes.
Explanation:
Crossing over is the event that occurs during the pachytene stage of prophase I of meiosis I and results in the formation of new gene combinations, that is, recombination. During pachytene of prophase I, the synapsed homologous chromosomes exchange the genetic segments between them.
To facilitate recombination, synaptonemal complex assists in pairing the homologous chromosomes together during the zygotene stage of prophase I. Zygotene is followed by pachytene. A cut in two non-sister chromatids of a homologous pair, exchange of the broken segments followed by ligation results in recombination. Prophase II does not include crossing over.
Nutrients would not be recycled. Thus the cycle could not continue and the soil does not contain nutrients. which means plants cannot grow and animals wont have plants to eat and their predators will have no food to eat.
Autotroph: Any kind of plant because they can create their own food.
Heterotroph: Humans because we can't create our own food.