Question

The following diagram shows nondisjunction in the Meiosis or Meiosis IL The cel has only one part of homologous chromosomes fertilized with a normal healthy gamete, which cell will most likely give normal offspring 26 99 88 se 0 0 DOQO | QOQO Select one a AC and D b. only CA and D d. A. and D e.only

Answer 1

Answer:

The parent cell has a single pair of homologous chromosome (2n). In a normal case, this parent cell would form 4 daughter cells which are all haploid (n).

However, due to non-disjunction abnormal gametes are produced. If non-disjunction takes place during meiosis I, then two gametes contain one chromosome more than the normal number (n+1) whereas two gametes contain one chromosome less than normal (n-1).

normal offspring? (18) BE (18 O SE ID DOO MOIDO n n I ]

If non-disjunction takes place during meiosis II, then two gametes are normal (n), one is trisomic (n+1) and one is monosomic (n-1).

The gamete cell which is haploid (n) is normal and can participate in normal fertilization process to produce normal offspring.

Here, gamete C is normal and can produce normal offspring upon fertilization by another healthy normal gamete.

Correct choice should be:

(b) only C