High School Biology : Evolutionary Principles
Study concepts, example questions & explanations for High School Biology
All High School Biology Resources
Example Questions
Example Question #141 : Genetics And Evolution
Which of the following is true regarding mitochondrial DNA?
It is found in the nucleus and in humans, it is passed down only through the maternal line, from a mother to her children.
It is found in the mitochondria and in humans, it is passed down only through the maternal line, from a mother to her children.
It is found on a plasmid in the nucleus.
It is found in the nucleus and in humans, it is passed down only through the paternal line, from a father to his children.
It is found in the mitochondria and in humans, it is passed down only through the paternal line, from a father to his children.
It is found in the mitochondria and in humans, it is passed down only through the maternal line, from a mother to her children.
The correct answer is that mitochondrial DNA is found in the mitochondria, where it takes the form of a plasmid, or ring-shaped structure characteristic of bacterial DNA. (This provides evidence in favor of the endosymbiotic theory.) Furthermore, in humans and in many other organisms, mitochondrial DNA is passed down solely through the maternal line. Note that the answer choice "It is found in a plasmid in the nucleus" is inherently non-sensical; plasmids are characteristic of prokaryotes, which do not have nuclei, as they do not have membrane-bound organelles.
Example Question #11 : Identify Evidence For Evolution
What's the difference between homologous and analogous structures?
Homologous structures result from a common ancestor; analogous structures result from repetitive usage by the individual (and are passed to offspring)
Homologous structures result from repetitive usage by the individual (and are passed to offspring); analogous structures result from a common ancestor
Homologous structures result from convergent evolution; analogous structures result from a common ancestor
Homologous structures result from a common ancestor; analogous structures result from convergent evolution
There is no difference between homologous and analogous structures
Homologous structures result from a common ancestor; analogous structures result from convergent evolution
Homologies are physical similarities resulting form common ancestry. This is the reason that related species share similar features. Therefore, homologous structures are anatomical similarities in organisms due to a shared ancestry. On the other hand, analogous structures are the result of convergent evolution. Convergent evolution is defined as the evolution of similar anatomical features in independent evolutionary lineages. In response to a changing environment, natural selection favored animals with similar traits or features that evolved independently as a result of adaptation to environmental alterations.
All High School Biology Resources
