Question

DNA present in small structures outside the nucleus of a cell, mitochondria, supplies energy to the cell. Is this form of DNA inherited maternally?

1) Yes
2) No

Answer 1

Mitochondrial DNA (mtDNA) is inherited maternally, meaning it is passed down from mothers to their offspring. This makes mtDNA a crucial marker for tracing genealogy and understanding evolutionary relationships according to the endosymbiotic theory.

Step-by-step explanation:

Is the form of DNA in mitochondria inherited maternally? Yes, mitochondrial DNA (mtDNA) is indeed passed down from mothers to their offspring. Mitochondria, the structures within cells that help supply energy, contain their own DNA separate from the nuclear DNA. Unlike nuclear DNA, which is inherited from both parents, mtDNA comes exclusively from the mother. Each cell contains many mitochondria, and each mitochondrion contains multiple copies of mtDNA.

This maternal inheritance is significant because it is conserved through generations, making it a valuable tool for tracing genealogy. Moreover, the mitochondrial DNA mutates at a rapid rate, providing insights into evolutionary relationships. According to the endosymbiotic theory, mitochondria originated from free-living prokaryotes that were engulfed by ancient eukaryotic cells, leading to a symbiotic relationship beneficial for both the prokaryotes and eukaryotic hosts.

Understanding this unique aspect of inheritance allows us to map human history and study diseases caused by mitochondrial dysfunction, since the mtDNA mutates quickly and plays a crucial role in cellular energy production and metabolism.