Florida Biology EOC key terms

A large molecule built from smaller repeating units, such as carbohydrates, lipids, proteins, and nucleic acids. Each type performs specific jobs in cells, from storing energy to carrying genetic instructions.

A macromolecule made of amino acids folded into a specific shape. Proteins build structures, speed up reactions, transport materials, and carry signals, and their shape determines what job they can do.

A protein that speeds up a chemical reaction by lowering the energy needed to start it. Each enzyme works best at a certain temperature and pH and fits only certain molecules.

The specific molecule an enzyme binds to and changes during a reaction. The substrate fits into the enzyme's active site, much like a key fitting a lock.

The minimum energy required for a chemical reaction to begin. Enzymes lower this barrier so reactions happen fast enough to support life without raising temperature.

The small building block that proteins are made from. Twenty common types link in different orders to form proteins, and that order determines the protein's final shape and function.

A macromolecule that stores and transmits genetic information. DNA holds the instructions for making proteins, while RNA carries and interprets those instructions inside cells.

Deoxyribonucleic acid, the double-stranded molecule that stores hereditary information. Its sequence of bases encodes instructions for building proteins and is copied before a cell divides.

Ribonucleic acid, a single-stranded nucleic acid involved in making proteins. Messenger RNA carries instructions from DNA, and other RNA types help assemble amino acids into proteins.

The process in which a cell copies a segment of DNA into messenger RNA. This occurs in the nucleus of eukaryotic cells and is the first step of gene expression.

The process in which ribosomes read messenger RNA and link amino acids into a protein. Transfer RNA brings the correct amino acids based on each three-base codon.

A thin barrier of lipids and proteins surrounding every cell. It controls which substances enter and leave, allowing the cell to maintain a stable internal environment.

The movement of particles from an area of higher concentration to an area of lower concentration. This passive process requires no energy and continues until concentrations are balanced.

The diffusion of water across a membrane toward the side with more dissolved particles. It is passive and helps cells keep proper water balance in different surroundings.

The process by which plants, algae, and some bacteria use sunlight to turn carbon dioxide and water into glucose and oxygen. It captures energy that most food chains depend on.

The process cells use to release energy from glucose, producing ATP along with carbon dioxide and water. It occurs in the cytoplasm and mitochondria and powers most cell activities.

Adenosine triphosphate, a molecule that stores usable energy in its phosphate bonds. Cells break off a phosphate group to release energy for reactions and other work.

An organelle in plant cells that contains chlorophyll and carries out photosynthesis. It captures light energy and converts it into chemical energy stored in glucose.

An organelle that produces most of a cell's ATP through cellular respiration. Cells with high energy needs, such as muscle cells, typically contain many mitochondria.

The division of a cell's nucleus that produces two genetically identical daughter cells. It is used for growth, repair, and replacement of body cells in multicellular organisms.

A type of cell division that produces four sex cells, each with half the normal chromosome number. It creates genetic variation through crossing over and independent assortment.

The repeating sequence of growth, DNA copying, and division that a cell goes through. Checkpoints along the cycle help prevent errors that could lead to uncontrolled growth.

The science of naming, describing, and classifying living things into groups based on shared traits. Modern classification reflects evolutionary relationships among organisms.

The two-part naming system for species, using a capitalized genus name and a lowercase species name, both often in Latin. Names are standardized so scientists worldwide refer to the same organism.

A group of organisms that can interbreed and produce fertile offspring under natural conditions. Members share common traits and a distinct evolutionary lineage.

A tool that identifies organisms through a series of paired choices, each leading to another pair until a name is reached. It relies on observable, contrasting characteristics.

A branching diagram showing evolutionary relationships among organisms. Closely related groups share a more recent common ancestor, shown by branches joining near the tips.

Change in the inherited traits of a population over generations. It is driven mainly by natural selection acting on variation, and it can produce new species over long periods.

The process by which individuals with traits better suited to their environment survive and reproduce more, passing those traits on. Over generations this changes the population's traits.

An inherited trait that helps an organism survive and reproduce in its environment. Adaptations arise over generations through natural selection rather than by choice.

An organism's ability to survive and produce offspring that carry its genes into the next generation. Higher fitness means a trait is more likely to become common.

A change in the DNA sequence of a gene or chromosome. Mutations are the original source of new genetic variation, and some can be harmful, neutral, or helpful.

One of the alternative versions of a gene that a person can inherit. Different alleles can produce different traits, and an organism's combination of alleles shapes its phenotype.

The specific combination of alleles an organism carries for a trait. It is written with letters, such as Bb, and interacts with the environment to produce observable traits.

The observable characteristics of an organism, such as eye color or height. Phenotype results from genotype interacting with environmental factors.

A trait that appears in an organism when at least one dominant allele is present. It masks the effect of a recessive allele in a heterozygous individual.

A trait that appears only when an organism carries two recessive alleles for that gene. A single dominant allele prevents it from being expressed.

The exchange of genetic material between paired chromosomes during meiosis. It produces new allele combinations, increasing genetic variation in the resulting sex cells.

A reproductive cell, such as a sperm or egg, that carries half the normal number of chromosomes. Two gametes join during fertilization to form a new organism.

The formation of new species when populations become reproductively isolated and diverge over time. Isolation can result from geographic barriers or other factors that prevent interbreeding.

An earlier organism from which two or more later groups descend. Shared features often indicate a common ancestor, which is why related species resemble one another.