Select the correct statements.

(a) Secondary oocyte is diploid.

(b) Primary spermatocyte is diploid.

(c) Oogonium is haploid.

(d) Secondary spermatocyte is haploid.

(b) and (d) are correct.

(a) Secondary oocyte is haploid. The oocyte undergoes meiosis II to become haploid.
(b) Primary spermatocyte is diploid. Spermatogonia undergo mitosis to form primary spermatocytes.
(c) Oogonium is diploid. Oogonia are the diploid germ cells that undergo mitosis to produce primary oocytes in females.
(d) Secondary spermatocyte is haploid. Secondary spermatocytes are produced after the first meiotic division during spermatogenesis and are haploid cells.