B may d answer 4 following question
Answer:
D) D, B, C, E, A, F
Explanation:
Homologous recombination (HR) is a DNA repair pathway that consists of the exchange between two identical (or very similar) DNA regions. The steps of HR are: 1-Strand exchange, which refers to the pairing between broken DNA regions; 2-Strand invasion in order to provide a DNA crossover (Holliday junction); 3- Branch migration, capable of extending the heteroduplex regions far away from DNA crossover, 4-Resolution, where Holliday junction is resolved by cleavage of the junctions; 5- In the last step, a DNA ligase enables the joining of DNA strands.
Cnidarians have specialized cells known as cnidocytes (“stinging cells”) containing organelles called nematocysts. These cells are concentrated around the mouth and tentacles of the animal and can immobilize prey with toxins. Nematocysts contain coiled threads that may bear barbs.
Mutations. Definition. A Mutationoccurs when a DNA gene is damaged or changed in such a way as to alter the genetic message carried by that gene. A Mutagen is an agent of substance that can bring about a permanent alteration to the physical composition of a DNA gene such that the genetic message is changed
