Many people believe that a child “takes more DNA from the mother,” but the truth is more detailed and biological. A child gets 50% of their nuclear DNA from the father and 50% from the mother—but certain biological mechanisms make maternal influence appear stronger in some areas.

Below is a clear breakdown of why maternal DNA or traits can seem dominant.

1. The Child Receives 100% of Mitochondrial DNA from the Mother

This is the biggest scientific reason maternal DNA seems dominant.

Mothers pass down mitochondria, the energy-producing structures inside cells.
Mitochondria have their own DNA, separate from nuclear DNA.
The egg contains mitochondria; the sperm does not.
Therefore, all humans inherit 100% of their mitochondrial DNA (mtDNA) from their mother.

Why this matters

Mitochondrial DNA affects:

metabolism
cellular energy
aging factors
some inherited diseases

This gives the mother a unique genetic influence that the father cannot contribute.

2. The Mother’s Body Controls the Child’s Development

Even though DNA is 50/50, the mother’s biological environment shapes the baby profoundly.

The mother controls:

nutrients delivered to the fetus
hormones that regulate development
immune protection
uterine environment
epigenetic signals (chemical tags that activate or silence genes)

Epigenetics

During pregnancy, the mother’s body adds biochemical “switches” that determine:

which genes turn ON
which genes turn OFF

So even when both parents give equal DNA, the mother has more influence on how genes EXPRESS.

3. X-Chromosome and Parental Imprinting

Females give one X chromosome; males give X or Y.

This can also influence dominance.

If the child is female (XX), one X comes from the mother, one from the father.
If the child is male (XY), the only X chromosome comes from the mother, while the father provides the Y.

Thus:

Sons inherit almost all X-linked traits from the mother.
Daughters inherit half of X-linked traits from the mother.

This makes maternal traits appear more dominant in many cases.

4. The Egg Carries Far More Biological Material Than the Sperm

The size difference is extreme:

Egg = largest human cell
Sperm = one of the smallest

The egg provides:

cytoplasm
mitochondria
nutrients
organelles
RNA
cellular machinery for early development

The sperm provides only nuclear DNA.

Thus, the mother contributes far more biological components to early embryonic life.

5. Behavioral and Physical Traits Can Appear More Maternal

Even though genes are shared 50/50, some traits look more maternal due to:

gene dominance patterns
epigenetic imprinting
mitochondrial influence
X-linked inheritance
maternal phenotype being expressed during fetal development

Example: Face shape, metabolism, and birth weight often resemble the mother.

Summary

A child does not receive more nuclear DNA from the mother.
But maternal genetic influence appears stronger because:

Mother’s Dominant Contributions:

100% mitochondrial DNA (exclusive to mother)
Control of uterine environment and gene expression
X-chromosome dominance (especially in boys)
Egg contributes far more biological material
Epigenetic “switches” controlled by the mother

So scientifically, the mother’s influence in early life and cellular function makes her DNA seem more dominant, even though both parents contribute equally to genetic code.