BIO BENCHMARK

Meiosis: A type of cell division that reduces chromosome number by half, creating four haploid gametes.
Outcome of Meiosis: 4 genetically unique haploid cells (sperm or egg).
Mendel’s Law of Dominance: Dominant alleles mask recessive ones in heterozygous individuals.
Mendel’s Law of Independent Assortment: Genes for different traits sort independently during gamete formation.
Mendel’s Law of Segregation: Each gamete gets only one allele per gene from each parent.
Nondisjunction: Failure of chromosomes to separate properly during meiosis, leading to disorders like Down syndrome.

Punnett Squares: Used to predict genotype and phenotype probabilities in offspring.
Gene Flow: Movement of alleles between populations (e.g., migration).
Genetic Drift: Random changes in allele frequencies, especially in small populations.
- Founder Effect: Small group starts a new population with limited gene variation.
- Bottleneck Effect: A population drastically decreases, reducing genetic diversity.

Homologous Structures: Similar structures, different functions → suggest common ancestry.
Analogous Structures: Similar functions, different structures → no common ancestry.
Vestigial Structures: Reduced or nonfunctional traits (e.g., human tailbone).
Evolution: Change in allele frequencies over generations.
Gradualism: Slow, continuous evolutionary change.
Natural Selection: Organisms with advantageous traits survive and reproduce more.
Adaptation: Traits that enhance survival become more common in a population.
Environmental Changes: Can lead to species increasing, new species forming, or extinctions.

DNA & Protein Synthesis: DNA → RNA → Protein (Central Dogma).
Mitosis: Cell division creating two identical diploid cells for growth/repair.
Macromolecules: Carbs (energy), Lipids (storage), Proteins (structure/enzymes), Nucleic Acids (genetic info).