In which phase of mitosis does the nuclear envelope reform around the chromosomes? MCQ with Answer and Explanation

Explanation:
Helicase unwinds the DNA helix at the replication fork by breaking hydrogen bonds between base pairs. DNA polymerase adds nucleotides, ligase seals Okazaki fragments, primase synthesizes RNA primer. This coordinated action ensures accurate semi-conservative replication. Without helicase, the strands would not separate. Energy for unwinding comes from ATP hydrolysis.

Explanation:
Charles Darwin proposed the theory of evolution by natural selection, where organisms with favorable traits survive and reproduce. Homologous organs share a common structural plan and evolutionary origin, indicating divergent evolution from a common ancestor. Evolution does not lead to perfection; it only results in adaptation to the current environment. Thus, statements 1 and 3 are correct.

Explanation:
The biceps brachii is a two-headed muscle located in the upper arm, responsible for flexing the elbow. The quadriceps femoris is a large, four-headed muscle group in the front of the thigh, extending the knee. The diaphragm is a dome-shaped skeletal muscle that forms the floor of the thoracic cavity and the roof of the abdominal cavity, crucial for breathing. All statements are correct.