Different genes are located on different kinds of genetic elements - autosomes, W chromosomes, the mitochondrial genome, etc. Different elements are transmitted in different ways, so different parents transmit different elements to different offspring.

For each case, answer 'both sons and daughters, 'only sons, 'only daughters, or 'neither sons nor daughters.' For instance, fathers transmit autosomal genes to both sons and daughters, but fathers inherit Y chromosome genes to only sons. If a parent is not expected to have such genes, answer 'neither sons nor daughters.'

1) Mothers transmit Y chromosome genes to:

2) Fathers transmit X chromosome genes to:

3) Mothers transmit mitochondrial genes to:

4) Mothers transmit z chromosome genes to:

5) Mothers transmit W chromosome genes to:

1) Mothers transmit Y chromosome genes to: neither sons nor daughters

In humans, the females are homozygous for sex chromosomes and are XX. Since they do not have the Y chromosomes, therefore, they neither transmit the chromosomes to boys or girls.

2) Fathers transmit X chromosome genes to: only daughters

In humans, the males are heterozygous for sex chromosomes that is they are XY and will transmit their X chromosome only to daughters as the Y chromosomes are male determining chromosome.

3) Mothers transmit mitochondrial genes to: both sons and daughters

Mothers transmit the mitochondrial gene to both the sons and daughters as the mitochondria is an organelle which is transmitted from the mother independent of the sex of the offspring.

4) Mothers transmit z chromosome genes to: only sons

In birds, the males are homozygous and are ZZ and the females are the ZW. The females transmit the Z chromosome to the sons as the W chromosome is the female determining chromosome.

5) Mothers transmit W chromosome genes to only daughters

Mothers transmit the W chromosome always to daughter as the W chromosome is involved in the sex determination.