BIO4 Flashcards
BIO4
How do viruses extend the central dogma of molecular biology?
Viruses can reverse transcribe RNA into DNA, extending DNA->RNA->Protein flow.
What is the difference between the lytic and lysogenic cycles of viruses?
Lytic cycle destroys host cells; lysogenic cycle integrates viral DNA into host genome.
What characterizes a retrovirus?
Retroviruses use reverse transcription to integrate into host DNA.
How can sequence alignments be used to construct phylogenetic trees?
Alignments reveal similarities and help infer evolutionary relationships.
What is the evidence that all life on Earth descends from a common ancestor, LUCA?
Shared molecular features across species support LUCA’s existence.
What are the conditions for evolution in biology?
Variation, inheritance, selection, and time allow evolution.
What is an allele? What is the gene pool?
An allele is a gene variant; the gene pool is all alleles in a population.
How can genetic diversity in a population be increased?
Through mutations, recombination, and migration.
What are examples of mutagens?
Examples include UV radiation and chemical exposure.
How can mutations lead to changes in gene expression?
Mutations can alter gene regulation or protein structure.
Why can gene duplication be useful for evolution?
Duplication provides extra genes that can evolve new functions.
What is horizontal gene transfer?
Horizontal gene transfer allows gene sharing across organism, species - not parent/offspring.
What is a genome-wide association study?
Associates genetic variants with traits to study diseases.
What is adaptive laboratory evolution and what is it useful for?
Selectively evolving organisms for desired traits in lab settings.
What is convergent evolution?
Different species evolve similar traits due to similar pressures.
How have humans shaped biomass distribution on Earth?
Humans impact distribution through agriculture and urbanization.
What is a gene drive and what can it be used for?
A gene drive spreads a trait through populations quickly.
What is the ecological justification for de-extinction of the Tasmanian tiger?
Restoring ecosystems by reintroducing a key species.
Why can’t an extinct animal be recreated solely based on its DNA?
DNA alone lacks epigenetic and environmental context.
What are problems from excess nitrogen in the biosphere?
Excess nitrogen disrupts ecosystems and causes water pollution.
What problem results from methane production in agriculture?
Methane contributes to greenhouse gas emissions.
What is the difference between genetic engineering and breeding?
Genetic engineering directly alters DNA; breeding selects traits.
