Question

Mitochondrial DNA is advantageous for evolutionary studies because

• A. it is inherited only through the female parent and allows trees of relationship to be constructed easily
• B. it is inserted into X chromosome
• C. it appears in humans and is not found in other animals
• D. it evolves more slowly than the genes in nucleus

Hint:

The lack of recombination in mitochondrial DNA allows researchers to trace maternal ancestry back to a single common female ancestor, often termed the "Mitochondrial Eve."

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Eukaryotic cells contain DNA in both the nucleus and within mitochondria.
Mitochondrial DNA (mtDNA) has unique genetic properties that make it highly valuable for evolutionary biology and phylogenetics.

Step 2: Detailed Explanation:
Mitochondrial DNA has several advantages for evolutionary and phylogenetic studies:
Maternal Inheritance: In most animals, mitochondria are inherited exclusively from the mother via the egg cell. Sperm mitochondria are degraded after fertilization.
This uniparental inheritance prevents recombination, which routinely reshuffles nuclear genes during meiosis.
Haploid Nature: Without recombination, the mitochondrial genome is passed down as an intact molecule, changed only by maternal mutations.
This makes it straightforward to construct maternal lineages and phylogenetic trees without the complications of heterozygosity.
High Mutation Rate: The mutation rate of mtDNA is higher than that of nuclear DNA, which provides sufficient sequence variation to resolve evolutionary relationships among closely related species.
Therefore, maternal inheritance and the lack of recombination simplify the reconstruction of evolutionary lineages.

Step 3: Final Answer:
Mitochondrial DNA is advantageous for evolutionary studies because it is inherited exclusively through the female parent, allowing maternal lineages to be easily reconstructed.