The given diagram shows a stage during mitotic division in an animal cell: The given diagram shows a stage during mitotic division in an animal cell:
Name the type of cell division that occurs during: A. Growth of a shoot B. Formation of pollen grains
Topic: Mitosis and meiosis
Answer
A. Growth of a shoot — MITOSIS B. Formation of pollen grains — MEIOSIS
THE RULE that decides every such question: MITOSIS for GROWTH AND REPAIR of body cells; MEIOSIS ONLY for the formation of GAMETES.
A POLLEN GRAIN carries the MALE GAMETE of a flowering plant, so it must be formed by meiosis — exactly as sperms are in an animal. The principle is the same in both kingdoms.
MITOSIS — number of chromosomes UNCHANGED; TWO daughter cells, genetically IDENTICAL. Which is what growing a shoot requires. MEIOSIS — number HALVED; FOUR daughter cells, NOT identical. Necessary so that fertilisation restores the full number rather than doubling it each generation.
Meiosis also produces VARIATION, through crossing over and independent assortment.