excretory system: removes waste from blood.
respiratory system: obtains oxygen so the energy in the nutrients can be extracted.
circulatory system: transports nutrients from small intestine to the othet tissues.
nervous system: regulates and controls digestive functioning.
( Am not completly sure, but i think this is the answer)
Correct answer: Option D- DNA ligase
Explanation: In option A, thymine is a nucleotide, so it is present throughout the replication process, wherever it is required. It is added to the newly formed DNA. In option B, Helicase enzyme is active during initiation and elongation stage, as it facilitates the opening of the winded DNA strands. Option C is nucleotidase and it has no role in DNA replication. So, the correct answer is DNA ligase, which is option D.
The okazaki fragments formed during DNA replication are sealed at the end. And in this step, DNA ligase is used. It catalyzes the formation of phosphodiester bond between the nucleotides of okazaki fragments. So it is the last active molecule of the process.
Cutaneous membrane also known as the skin
The best answer to fill in the blank would be B) Small intestine or the second option.