Living Environment & Biology Vocabulary

Vocabulary-style flashcards covering scientific inquiry, biochemistry, homeostasis, cell biology, genetics, evolution, and ecology based on the Living Environment review outline.

Observation

What is seen or measured.

Inference

A conclusion based on observation or evidence.

Hypothesis

A prediction based on available evidence that states both cause and effect, often written as an "if-then" statement.

Theory

An explanation of natural events that is supported by strong evidence and ties together many scientific facts, hypotheses, and laws.

Experimental group

The group in a controlled experiment that is being tested or receiving treatment.

Control group

The "normal" group in an experiment that is identical to the experimental group except it does not receive the new treatment.

Independent Variable

The variable being tested (the "if" part of a hypothesis) which is always plotted on the x-axis.

Dependent Variable

The variable measured at the end of an experiment (the results or "then" part of a hypothesis) which is always plotted on the y-axis.

Peer review

The process of having an experiment examined by several scientists to determine its accuracy.

Organic Compounds

Molecules that contain both Carbon and Hydrogen, such as $C_6H_{12}O_6$.

Carbohydrates

Sugars and starches made from simple sugars like glucose that supply energy to the organism.

Lipids

Molecules used to store energy, including fats, oils, and waxes.

Proteins

Molecules made from amino acids; their shape determines their function in building and running an organism's body.

Enzymes

Proteins that act as catalysts to affect the rates of chemical reactions using a lock and key model.

pH

A scale measuring the strength of acids ($0-6$) and bases ($8-14$), with $7$ being neutral.

Homeostasis

A balanced state in an organism.

Dynamic equilibrium

The process by which the body stays balanced by taking action whenever the balance is disturbed.

Metabolism

The term used to describe all basic life processes/functions.

Diffusion

The passive transport of molecules from high concentrations to low concentrations without the use of energy.

Active Transport

The movement of molecules from a low concentration to a high concentration, which requires the use of energy ($ATP$).

Osmosis

The diffusion of water into or out of the cell.

Autotrophs

Organisms like plants, alga, and blue-green bacteria that make their own food.

Heterotrophs

Organisms that must eat other organisms for food.

Photosynthesis

The process that stores radiant energy from the sun in the bonds of sugar molecules (glucose).

Stomates

Holes in plant leaves that allow for the exchange of gasses used in photosynthesis.

Guard cells

Cells that open and close stomates to protect the plant from water loss (dehydration).

Respiration

The process that takes energy from sugar molecules and places it into molecules of $ATP$.

ATP

The energy source of all living things.

Aerobic respiration

Respiration that requires oxygen and yields more $ATP$ than anaerobic respiration.

Stimulus

A change in the environment that an organism responds to.

Neuron

A nerve cell.

Impulse

The electrical signal carried by the nerves.

Hormone

A chemical signal secreted by glands, such as insulin, adrenaline, testosterone, or estrogen.

Receptor molecules

Proteins on the surface of the cell membrane that receive chemical signals; their shape determines which signals they receive.

Cell Theory

States that all living things are made of one or more cells, cells carry out all life functions, and all cells come from other cells.

Differentiation

The process that changes a stem cell into a specialized tissue by turning specific genes on or off.

Antigens

Protein "tags" on the surface of a cell or virus that can be used to identify it.

Antibodies

Proteins made by white blood cells to attack specific antigens based on their shape.

Vaccine

An injection of a dead or weakened pathogen that prevents disease by causing the body to produce antibodies.

Antibiotics

Drugs used to stop bacterial infections; they cannot cure viral infections.

Excretory System

The system that removes metabolic cellular wastes, including salt, water, urea, and $CO_2$.

Mitosis

A form of asexual cell division producing two identical, diploid ($2n$) cells used for growth and healing.

Meiosis

Cell division used in sexual reproduction that produces four different haploid ($1n$) gametes.

Alleles

Different forms of a gene found on homologous chromosome pairs.

Mutation

A change in DNA that can only be passed to offspring if it occurs in reproductive cells (sperm or egg).

Genetic Engineering

Also called gene splicing, it is the insertion of genes from one organism into another, often using bacteria to produce medicine like insulin.

Natural Selection

The mechanism of evolution where organisms with beneficial variations survive and pass on their genes.

Evolutionary Fitness

A measure of how well an organism is adapted to survive in a particular environment and pass on its genes.

Niche

The specific role an organism plays in its ecosystem.

Carrying capacity

The maximum size of a population that an ecosystem's environmental factors can support.

Ecological succession

The basic process of gradual changes in an ecosystem over time.

Biodiversity

The variety of life on earth; high levels increase ecosystem stability and resource availability.