Mother is responsible for the sex of the baby
(a) True
(b) False
Hint: In humans, the female ovum contains homologous XX sex chromosomes, while the male sperm contains heterologous XY sex chromosomes. The combination of male and female sex chromosomes determines the baby’s sex.
Complete answer:
In humans, the sex of a baby is determined by the chromosome contributed by the father because males have heterologous XY chromosomes, while females have homologous XX chromosomes. During fertilization, if the male’s X chromosome combines with the female’s X chromosome, the resulting offspring will be a girl, having the homologous XX chromosome pair. However, if the male’s Y chromosome combines with the female’s X chromosome, the offspring will be a boy, possessing the heterologous XY chromosome pair. Thus, it is the father’s chromosome, not the mother’s, that determines the baby’s sex.
Additional Information:
Different organisms have varying chromosome configurations; not all males have heterologous sex chromosomes, nor do all females have homologous sex chromosomes. For example, in *Drosophila*, females have homologous XX chromosomes, while males have heterologous XY chromosomes. In birds, the female is heteromorphic with a ZW sex chromosome pair, while the male is homomorphic with a ZZ chromosome pair.
Therefore, the correct answer is false.
Note:
Plants that reproduce sexually also possess chromosomes resembling those found in certain insects, such as roundworms, grasshoppers, and cockroaches. Examples of these plants include *Vallisneria*, *Dioscorea*, and *Fragaria*. In these species, the female plants have sex chromosomes in the form of AX, while the male plants have AO.