Correct answer:
"<span>B- homologous chromosomes join together to form tetrads during prophase I"
</span>It is during prophase I that homologous chromosomes join together (<span>synapsis)</span> and form tetrads - four chromatids are together in the new structure of two chromosomes - and this is the reason why crossing-over occurs in this phase. It is in this tetrad that both arms of both chromosomes may crossover and matching regions exchange places. This process results in homologous chromosomes recombination leading to genetic variability.
Abiogenesis is the theory that life arose from non living molecules to form the earliest life forms. In the simplest sense, once there is life, life will arise from living rather than non living matter. However, there are those who speculate that it is possible for abiogenesis to occur more than once.
Answer:
only 30% of total energy will be useful ..
So, Useful energy =
13.5J energy is useful
Answer:
D
Explanation:
because cell are not pre existing
Activation energy is the minimum quantity of energy that the reacting species must possess in order to undergo a specified reaction.
for example , striking a match on the side of a matchbox provides the activation energy, in the form of heat produced by friction.
