What are examples of extranuclear genes?

What are examples of extranuclear genes?

In organisms in which one gamete is much larger than the other, so that the smaller gamete contains very little cytoplasm, one parent will contribute most or all of the extranuclear genes. For example, human mitochondrial DNA is passed from generation to generation through the maternal line in the ovum.

What is extranuclear genetic material?

All of the genetic information in a cell was initially thought to be confined to the DNA in the chromosomes of the cell nucleus. It is now known that small circular chromosomes, called extranuclear, or cytoplasmic, DNA, are located in two types of organelles found in the cytoplasm of the cell.

Why are extranuclear genes typically inherited from the maternal parent?

Maternal inheritance is the most common form of extranuclear inheritance because the female gamete is relatively large and more likely to contain cell organelles. If the father was transmitting a dominant allele in the organellar genome (and the mother did not), then 3% of the offspring would exhibit the trait.

How is cpDNA inherited?

Chloroplast DNA (cpDNA) is maternally inherited in the majority, but not all, of angiosperm species. PCR/RFLP markers were used to compare mother and offspring cpDNA genotypes sampled from two natural populations, and mother, father, and offspring genotypes obtained from controlled greenhouse crosses.

What causes Extranuclear inheritance?

Uniparental inheritance occurs in extranuclear genes when only one parent contributes organellar DNA to the offspring. A classic example of uniparental gene transmission is the maternal inheritance of human mitochondria. The mother’s mitochondria are transmitted to the offspring at fertilization via the egg.

What does paternally inherited mean?

Abstract. Paternal inheritance refers to the transmission of any attribute from a father to his offspring. Most paternally inherited traits can be explained by the inheritance of nuclear genes, which are contributed by the male parent and expressed in his progeny.

Can you inherit stress?

Some people are genetically predisposed to higher stress levels. While all of us feel stressed at some point or another, some people battle with stress more frequently. This boils down to genetics. Your genes produce proteins which dictate how your body functions.