77. Molecular evolution. Flashcards
(30 cards)
What is molecular evolution?
It is the study of how DNA, RNA, and proteins change over time in living organisms.
What does DNA do in a cell?
DNA carries instructions that control how a cell works and passes traits to offspring.
What is a mutation?
A mutation is a change in the DNA sequence.
Are all mutations harmful?
No, some are helpful, some are harmful, and many have no effect.
What is natural selection?
It is when helpful mutations help an organism survive and get passed on.
What is genetic drift?
It is random change in gene frequency, especially in small populations.
Is genetic drift based on usefulness?
No, it happens by chance, not because of survival advantage.
What is gene duplication?
It is when a gene is copied in the DNA, allowing new functions to evolve.
What is horizontal gene transfer?
It is when genes move between different species, often in bacteria.
Why is gene duplication important?
It can lead to the creation of new proteins and traits.
What molecules are most often studied in molecular evolution?
DNA, RNA, and proteins.
How do scientists study molecular evolution?
By comparing DNA or protein sequences between species.
What does it mean if two species have similar DNA?
They are closely related and share a recent common ancestor.
What is an evolutionary tree?
A diagram showing how species are related through common ancestors.
What percent of DNA do humans share with chimpanzees?
About 98–99%.
What is the main cause of long-term genetic change?
The accumulation of many small mutations over time.
How does molecular evolution help in medicine?
It helps us understand viruses and create better vaccines and treatments.
Why do viruses like HIV or flu evolve quickly?
Because they mutate rapidly, helping them escape immunity or drugs.
How does molecular evolution help in agriculture?
It helps improve crops by studying how plants resist pests or drought.
How does molecular evolution help in anthropology?
It helps trace human ancestry and migration using DNA.
What are the four DNA bases?
A (adenine), T (thymine), C (cytosine), and G (guanine).
What happens if a mutation gives an advantage?
It is more likely to be passed on to future generations.
What kind of populations are more affected by genetic drift?
Small populations.
What is one example of horizontal gene transfer in real life?
Antibiotic resistance spreading between bacteria.
