Theory question 104
Cell Division(a)(i) Complete the table below by stating the type of cell division and the type of set of chromosomes for the listed cells.
Table columns: Cell | Types of cell division | Set of chromosomes
Rows: Onion cell | mitosis | ______; Sperm cell; Pollen grain; Ovum; Guard cell; Cheek cell | ______ | diploid
(ii) What is mitosis?
(b) Explain briefly how parents with blood groups A or B could have an offspring with blood group O.
(c) Explain briefly how genes are involved in the process of evolution.
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(a)(i) Onion cell - mitosis - diploid; Sperm cell - meiosis - haploid; Pollen grain - meiosis - haploid; Ovum - meiosis - haploid; Guard cell - mitosis - diploid; Cheek cell - mitosis - diploid.
(ii) Mitosis is cell division in which one cell divides to give two daughter cells with the same number and kind of chromosomes as the parent cell.
(b) Group O is recessive (genotype OO). A parent of group A can be AO and a parent of group B can be BO. If each passes on the O allele, the child is OO, group O (chance ¼ in AO x BO, AO x AO or BO x BO).
(c) Genes carry characteristics from parents to offspring; mutations change genes and produce new variations; useful variations help some individuals survive and reproduce (natural selection); these genes become more common over generations, so the population changes (evolves).
Show the genotypes and the gametes in (b).