Living Environment Regents Review

Cells

The smallest units of life.

Organelles

Structures inside the cell.

Nucleus

Contains DNA that controls protein production.

Ribosomes

Read DNA messages to form proteins.

Mitochondria

Site of cellular respiration and ATP production.

Vacuoles

Store food or waste in cells.

Cytoplasm

Fluid where chemical reactions occur.

Cell Membrane

Controls what enters or exits the cell.

Selectively Permeable

Allows only certain substances to pass.

Diffusion

Movement from high to low concentration without energy.

Active Transport

Requires energy to move molecules against the gradient.

Receptor Molecules

Shape determines substances attached to the cell.

Chloroplasts

Site of photosynthesis in plant cells.

Nutrition

Nutrients needed for energy, repair, and growth.

Autotrophic Organisms

Produce food from inorganic molecules.

Heterotrophic Organisms

Rely on others for food.

Transport

Distribution of materials in the body.

Respiration

Release of energy from glucose.

Metabolism

All chemical reactions in an organism.

Regulation and Coordination

Essential for maintaining homeostasis.

Homeostasis

Internal stability in organisms.

Photosynthesis

Conversion of light energy into chemical energy.

Cellular Respiration

Conversion of chemical energy into ATP.

Enzymes

Proteins that catalyze metabolic reactions.

DNA

Genetic material carrying instructions for proteins.

Genes

DNA sequences that code for proteins.

Mutation

Error in DNA sequence causing genetic changes.

Selective Breeding

Choosing traits in offspring through mating.

Recombinant DNA

Inserting genes into an organism's DNA.

Asexual Reproduction

One organism divides into offspring.

Sexual Reproduction

Fusion of genes from two organisms.

Embryonic Development

Cell division and differentiation.

Evolution

Change in gene frequency over time.

Natural Selection

Process favoring genes for survival.

Adaptive value

Genes that provide a survival advantage and are passed on to offspring.

Genetic variation

Differences in DNA among individuals in a population.

Common ancestry

Species sharing a genetic relationship leading to similarities in DNA, proteins, and structures.

Biosphere

Regions on Earth where life exists.

Species

Interbreeding group of organisms.

Community

All populations of different species in an ecosystem.

Ecology

Study of interactions between living and nonliving elements.

Ecosystem

Interaction between biotic (living) and abiotic (nonliving) factors in an area.

Abiotic factors

Nonliving elements influencing habitat and organism distribution.

Biotic factors

Living components aiding in recycling abiotic materials.

Energy pyramid

Representation of energy transfer between trophic levels in an ecosystem.

Food chain

Sequence of energy transfer from producers to consumers.

Food web

Interconnected network of multiple food chains in an ecosystem.

Photosynthesis

Process where plants use sunlight to convert CO2 and H2O into glucose.

Niche

Role of an organism in its environment.

Decomposers

Organisms breaking down dead matter.

Autotrophs

Organisms capable of producing their own food.

Heterotrophs

Organisms relying on others for food.

Ecological succession

Process where ecosystems evolve due to changes in plant and animal communities.