evolution 1 Flashcards
Zygote
Fertilized egg cell
Gametes
A reproductive animal/plant cell
Alleles
Alleles are a pair of genes (1 from each parent) that control the same trait. A pair of alleles can be heterozygous meaning they both differ, or homozygous meaning they’re both the same.
What causes variation? What eliminates the ability for variation to occur?
- Mutations in DNA sequence 2. Meiosis produces new combo of alleles 3. Sexual reproduction which gives a zygote genes from both its parents - Asexual reproduction produces cloned cells, means no variation can occur.
Nonsense mutations
Nonsense mutations cause a gene to not function properly or at all.
Missense mutations
Missense mutations cause variations that benefit the organism.
Silent mutations
Silent mutations are when a mutated codon still codes for the same amino acids so no change occurs.
Natural selection
Natural selection means that only the best adapted individuals will pass on their genes to the next generation.
Genetic drift
A genetic drift refers to the allele frequency within a species changing over time as a result of natural selection.
Transitional fossils
Transitional fossils are fossils that show links between ancestral groups.
Selective breeding
Selective breeding is the process of humans trying to artificially breed the organisms with the best traits so the generational lineage retains those desired traits
Homologous structure
A homologous structure refers to two things being similar in structure/evolutionary origin, but not function.
Analogous structure
An analogous structure refers to the function of two things being similar, but not structure/evolutionary origin.
Adaptive radiation
Adaptive radiation is a form of microevolution that involves organisms rapidly diverging from their original species.
Divergent evolution
Divergent evolution is when 2 species have similar structures, but they function in different ways.