Biology Flashcards
(23 cards)
what is frameshift mutations
insertions or deletions that mess up the entire protein code.
what is point mutations
changes in a single nucleotide (one “letter”) in a DNA sequence.
Substitution – One base is swapped for another (e.g., A → G).
Silent: No change in the protein.
Missense: Changes one amino acid in the protein.
Nonsense: Creates a stop signal, ending the protein early.
Charles Lyell’s contribution to the theory of evolution
Uniformitarianism, earth’s features are shaped slowly and evolution happens over time gradually.
Thomas Malthus contribution to the theory of evolution
he proposed that populations grow faster than resources, leading to competition
Jean-Baptiste Lamarck contribution to the theory of evolution
he proposed the theory of acquired inheritance, where changes aquired over a lifetime were passed to offspring
Charles Darwin contribution to the theory of evolution
he propsed the theory of evolution by natural selection
Stephen Jay Gould and Niles Eldredge contribution to the theory of evolution
they introduced the “theory of punctuated equilibrium” suggesting that species remain stable for long time then evolve rapidly during short events of environmental change
what are the three evidences of evolution?
- Biomolecules (DNA, RNA and protein sequences)
- Homologous structures
- selective breeding
how did lamarck and darwin help each other?
Lamarck’s theory was correct, but his mechanism wasnt (aquired inheritance). darwin built on his theory with a more accurate meechanism (natural selection).
what is selection pressure?
“pressures” an organism to adapt to the environment. It causes a particular phenotype to be more favourable in certain environmental conditions.
what is a pedigree chart?
A pedigree is a genetic family tree that shows how prevalent a trait is in a family unit from generation to generation, often used to track genetic conditions and disorders.
what is a phenotype vs. genotype?
Genotype = code
Phenotype = outcome
What is artificial selection vs. natural selection?
Artificial is controlled by humans and happens very quickly, whereas natural selects traits based on survival, and it happens slowly over generations ex. peppered moths
What are the benefits of GMO
Farmers don’t need to use pesticides, imporves famers health, profit, reduces pesticide use. Crops can become resistant to droughts, they can add nutrition to certain foods ex golden rice. it can
What are the disadvantages of GMO
Ethical: gives all the power to big corporations, and it makes crops restitant to pesticiedes, so farmers use more pesticieds
How is DNA evidence of evolution?
Similar DNA codes suggest species evolve from the same ancestor
how is homologous structures evidence of evolution?
body parts that look the same but have different functions, like arms. This proves that species inherited the structure from a common ancestor and adapted it for different uses.
how does pentadactyl limbs prove scientists theory of evolution?
even though all the limbs have different functions, the basic structure is the same. This suggests that they inherited it from a common ancestor and each one evolved due to natural selection to fit their environment.
What is the difference between Lamarck’s and Darwin’s theory of evolution?
lamarck believed that species aquired traits over their lifetime, and then passed them on to offspring. Darwin believed that random variation allowed the organisms with advantageous traits to survive and reproduce more.
What is the difference between heterozygous and homozygous?
Homozygous = same alleles (AA or aa)
Heterozygous = different alleles (Aa)
How to tell if its x-linked or autosomoal?
more males have it than females, and the males only pass it on to their daughters, it skips generations. Autosomal effects them equally, usually more straightforward inheritance pattern.
How to tell if its recessive or dominant?
dominant traits appear in every generation, and affected individuals have one affected parent. recessive traits skip generations parents can be unaffected and still have affected children.
answer to enzyme question
Answer: The plant requires a specific enzyme to produce blue flowers, but a gene needed to make that enzyme is missing or deleted. As a result, the enzyme isn’t produced, and the blue pigment can’t form, so the flowers turn out white instead.
