<span>
are always unicellular
may have evolved from prokaryotes
</span><span>are more primitive than prokaryotes
</span>
Answer:
Reciprocal altruism is one of the altruism behaviors in which an individual organism helps in increasing the fitness of another organism by reducing the fitness of itself temporarily in expectation of the same behavior from another organism in the future later.
It takes place in the same set of organism partners which is a continuous interaction ion in stable groups of organisms.
Thus, the correct answer would be - an ongoing interaction in the same set of partners.
Crossing over at prophase I results in the linked genes (those on the same chromosome) becoming unlinked and separated. Prophase I is this first stage of meiosis, the chromosomes condense, form tetrads, and exchange DNA. The nucleolus and nuclear envelope disappear.
<span>The cytoplasm of the cell.</span>
