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 with different functions, suggesting common ancestry.

Analogous Structures

Similar functions with different structures, indicating no common ancestry.

Vestigial Structures

Reduced or nonfunctional traits, such as the human tailbone.

Evolution

Change in allele frequencies over generations.

Gradualism

Slow, continuous evolutionary change.

Natural Selection

Process by which organisms with advantageous traits survive and reproduce more.

Adaptation

Traits that enhance survival becoming more common in a population.

Environmental Changes

Can lead to species increasing, new species forming, or extinctions.

DNA & Protein Synthesis

The process DNA → RNA → Protein, known as the Central Dogma.

Mitosis

Cell division creating two identical diploid cells for growth or repair.

Macromolecules

Biological molecules categorized as Carbohydrates (energy), Lipids (storage), Proteins (structure/enzymes), and Nucleic Acids (genetic info).