Genetics, Biology & Earth Science Overview

Vocabulary flashcards covering key genetics, biology, and earth science terms from the provided lecture notes.

Allele

One of two or more versions of a gene; can be dominant or recessive and is represented by a letter (e.g., B or b).

Genotype

The genetic makeup of an organism; the specific combination of alleles (e.g., BB, Bb, bb).

Phenotype

The observable physical traits of an organism, produced by its genotype.

Recessive trait

A characteristic expressed only when two matching recessive alleles are present (e.g., bb for blue eyes).

Dominant trait

A characteristic expressed when at least one dominant allele is present (e.g., Bb for brown eyes).

Heterozygous

Having two different alleles for a trait (e.g., Bb).

Homozygous

Having two identical alleles for a trait (e.g., BB or bb).

Chromatid

A single strand of DNA that pairs with its duplicate to form a chromosome.

Chromosome

An X-shaped structure of two chromatids that carries genetic information.

Gametes

Reproductive cells (sperm or egg) that carry half of the parent’s alleles.

Nucleic Acids

Large biomolecules (DNA and RNA) that store and transmit genetic information.

Nucleotides

Building blocks of nucleic acids composed of a nitrogenous base, a 5-carbon sugar, and a phosphate group.

Purines

Double-ring nucleotides adenine (A) and guanine (G).

Pyrimidines

Single-ring nucleotides cytosine (C), thymine (T), and uracil (U).

Nucleus

Cell organelle that houses DNA; the control center of the cell.

Mitochondria

Organelles known as the cell’s “powerhouse,” producing ATP.

ATP (Adenosine Triphosphate)

The energy-carrying molecule used by cells.

Cellular respiration

Process that converts glucose and oxygen into carbon dioxide, water, and ATP.

Photosynthesis

Process in plants that converts carbon dioxide, water, and sunlight into glucose and oxygen.

Chlorophyll

Green pigment that captures light energy for photosynthesis.

Glucose

Simple sugar (C6H12O6) produced by photosynthesis and broken down for energy in respiration.

Osmosis

Movement of solvent molecules through a membrane to equalize solute concentrations.

Aerobic

Describes a process that requires oxygen.

Anaerobic

Describes a process that occurs without oxygen.

Carbohydrates

Sugars and starches that serve as a primary energy source for organisms.

Proteins

Macromolecules made of amino acids; structural and functional components of cells.

Lipids

Fats, oils, and related molecules used for energy storage, insulation, signaling, and membranes.

Amino acids

Monomers (e.g., lysine, tryptophan) that build proteins.

Hormones

Chemical messengers that regulate bodily functions such as mood, hunger, and metabolism.

Fermentation

Anaerobic breakdown of glucose into carbon dioxide and alcohol or lactic acid to produce energy.

Endotherm

Warm-blooded organism that regulates its body temperature internally.

Ectotherm

Cold-blooded organism that relies on external sources for body heat.

Symbiotic relationships

Close interactions between species that benefit at least one partner.

Commensalism

Symbiosis where one organism benefits and the other is unaffected.

Mutualism

Symbiosis where both organisms benefit.

Parasitism

Symbiosis where one organism benefits and the other is harmed.

Taxonomic ranks

Hierarchical classification: Kingdom, Phylum, Class, Order, Family, Genus, Species.

Decomposers

Organisms (e.g., worms, mushrooms) that break down dead material.

Binomial nomenclature

Two-part Latin naming system for species (Genus + species), e.g., Homo sapiens.

Igneous rock

Rock formed from cooled magma or lava.

Sedimentary rock

Rock formed from the compaction of small particles like sand.

Metamorphic rock

Rock altered by heat and/or pressure.

Run-off

Movement of rainwater over land into rivers and lakes.

Crust

Earth’s thin, outermost layer.

Mantle

Thick layer beneath the crust; moves via convection of molten rock.

Outer core

Layer beneath the mantle that generates Earth’s magnetic field.

Inner core

Extremely hot, solid central layer of Earth.

Greenhouse gases

Gases (e.g., CO2, methane) that trap heat and warm Earth’s atmosphere.

Autotroph

Organism that produces its own food, typically via photosynthesis.

Heterotroph

Organism that obtains energy by consuming other organisms.

Primary consumers

Herbivores that eat autotrophs (plants).

Secondary consumers

Carnivores that eat primary consumers.

Tertiary consumers

Predators that eat secondary consumers.