The pulmonary veins carry: MCQ with Answer and Explanation

Explanation:
The centrosome, which contains two centrioles, duplicates during the S phase of the cell cycle, concurrent with DNA replication. This ensures that by the time the cell enters mitosis, it has two fully formed centrosomes to organize the mitotic spindle. G1 is for growth, G2 is for preparation for M phase, and M phase is for actual division.

Explanation:
RNA polymerase binds to the promoter region of DNA and synthesizes a complementary RNA strand during transcription. DNA polymerase synthesizes DNA, ligase joins DNA fragments, helicase unwinds DNA.

Explanation:
In a chloroplast, the thylakoids are flattened membranous sacs that are arranged in stacks like coins, which are called grana (singular: granum). The stroma is the fluid-filled matrix surrounding the thylakoids. The thylakoid membranes contain the pigments necessary for the light reactions of photosynthesis.