Biology

What are the 7 characteristics of living organisms?

1. Organization 2. Metabolism 3. Homeostasis 4. Growth and development 5. Reproduction 6. Response to stimuli 7. Adaptation and evolution.

What is organization?

Living things are made of organized structures, such as cells, tissues, and organs.

What is metabolism?

The chemical reactions that allow organisms to obtain and use energy.

What is homeostasis?

Maintaining stable internal conditions despite changes in the environment.

What is growth and development?

Living things increase in size and go through changes during their lives.

What is reproduction?

The ability to produce offspring.

What is response to stimuli?

The ability to react to changes in the environment.

What is adaptation and evolution?

Inherited characteristics change in populations over generations, helping organisms survive and reproduce.

What is the difference between living and nonliving things?

Living things perform life processes, while nonliving things do not.

What are the three domains of life?

Bacteria, Archaea, and Eukarya.

What domain do humans belong to?

Eukarya.

What kingdom do humans belong to?

Animalia.

What is a domain?

The largest and broadest classification group of organisms.

What is a kingdom?

A classification group within a domain.

What are the main classification levels?

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.

What is the difference between prokaryotes and eukaryotes?

Prokaryotes lack a nucleus; eukaryotes have a nucleus and membrane-bound organelles.

What are examples of prokaryotes?

Bacteria and Archaea.

What are examples of eukaryotes?

Animals, plants, fungi, and protists.

Why do biologists classify organisms?

To organize living things, identify relationships, and understand similarities and differences.

What is an atom?

The smallest unit of an element that retains its chemical properties.

What are examples of atoms?

Carbon, oxygen, hydrogen, and nitrogen.

What is a molecule?

Two or more atoms chemically bonded together.

What are examples of molecules?

Water, oxygen, carbon dioxide, and glucose.

What is a cell?

The smallest unit of life.

What are examples of cells?

Animal cells, plant cells, and bacterial cells.

What is a tissue?

A group of similar cells working together to perform a function.

What is an organ?

A structure made of different tissues working together.

What is an organ system?

A group of organs working together to perform a major function.

What is an organism?

An individual living thing.

What is a population?

All individuals of the same species living in one area.

What is a community?

All the different populations living in one area.

What is an ecosystem?

A community of living organisms interacting with their nonliving environment.

What is the biosphere?

All areas of Earth where life exists.

What is the correct order of biological organization?

Atom, molecule, cell, tissue, organ, organ system, organism, population, community, ecosystem, biosphere.

What is inductive reasoning?

Using specific observations to develop a general conclusion.

What is deductive reasoning?

Using a general rule to make a specific prediction.

What is an example of inductive reasoning?

Observing that several plants grow toward sunlight and concluding plants generally grow toward light.

What is an example of deductive reasoning?

All mammals breathe air. Whales are mammals. Therefore, whales breathe air.

When is inductive reasoning used?

When making general conclusions from observations.

When is deductive reasoning used?

When using an established idea or hypothesis to make predictions.

What are the steps of the scientific method?

Observation, question, hypothesis, prediction, experiment, results, and conclusion.

What is observation?

Noticing something and collecting information about it.

What is a scientific question?

A question about something that can be investigated through scientific research.

What is a hypothesis?

A possible explanation that can be tested.

What is a prediction?

An expected result if the hypothesis is correct.

What is an experiment?

A test designed to investigate a hypothesis.

What are results?

The information and data collected during an experiment.

What is a conclusion?

An explanation of what the results mean and whether they support the hypothesis.

What is the difference between a hypothesis and prediction?

A hypothesis explains why something happens; a prediction describes what should happen if the hypothesis is correct.

What is an example of a hypothesis?

Plants grow taller when they receive more sunlight.

What is an example of a prediction?

If plants receive more sunlight, they will grow taller.

What is a variable?

Anything that can change during an experiment.

What is a control group?

The group that does not receive the experimental treatment and provides a comparison.

What is an experimental group?

The group that receives the treatment being tested.

What is an independent variable?

The factor that the experimenter changes.

What is a dependent variable?

The factor that is measured or observed.

Where does the independent variable go on a graph?

On the X-axis (horizontal).

Where does the dependent variable go on a graph?

On the Y-axis (vertical).

What is the difference between a control and a variable?

A control provides a comparison, while variables are factors that can change or be measured.

Why are controls important in experiments?

They help determine whether the independent variable caused the results.

What are the three major challenges facing society?

Climate change, biodiversity loss, and emerging and reemerging diseases.

What is climate change?

Long-term changes in Earth's temperatures and weather patterns.

What is global warming?

The long-term increase in Earth's average temperature.

What causes global warming?

An increase in greenhouse gases, especially from human activities.

How does climate change affect humans?

It can cause extreme weather, food shortages, health problems, and rising sea levels.

How does climate change affect other organisms?

It changes habitats, food supplies, migration patterns, and survival.

What is biodiversity?

The variety of different living organisms in an environment.

What happens when biodiversity decreases?

Ecosystems become less stable and species may become endangered or extinct.

What is extinction?

When an entire species dies out.

What is an emerging disease?

A disease that is newly appearing or rapidly increasing in a population.

What is a reemerging disease?

A disease that was previously controlled but is becoming common again.

How do emerging diseases affect humans and animals?

They can spread through populations, cause illness, and threaten species.

What are the two main types of cells?

Prokaryotic and eukaryotic cells.

What is a prokaryotic cell?

A cell without a nucleus or membrane-bound organelles.

What is a eukaryotic cell?

A cell with a nucleus and membrane-bound organelles.

What are examples of prokaryotic organisms?

Bacteria and Archaea.

What are examples of eukaryotic organisms?

Animals, plants, fungi, and protists.

What do prokaryotic and eukaryotic cells have in common?

Both have DNA, ribosomes, cytoplasm, and a plasma membrane.

What is the main difference between prokaryotic and eukaryotic cells?

Eukaryotic cells have a nucleus; prokaryotic cells do not.

What is the plasma membrane?

The outer boundary of a cell that controls what enters and leaves.

What are the main functions of the plasma membrane?

Protects the cell, controls movement of substances, allows communication, and helps cells recognize each other.

What is the plasma membrane made of?

A phospholipid bilayer with proteins, cholesterol, and carbohydrates.

What is the fluid mosaic model?

The model describing the plasma membrane as a flexible phospholipid bilayer with moving proteins.

What is a phospholipid?

A molecule with a water-loving head and water-fearing tails.

What are membrane proteins?

Proteins that help transport substances, communicate, and recognize other cells.

What does selectively permeable mean?

Only allowing certain substances to pass through.

What is diffusion?

The movement of particles from high concentration to low concentration.

What is a concentration gradient?

A difference in the concentration of a substance between two areas.

What is passive transport?

Movement of substances without using cellular energy.

What is facilitated diffusion?

Movement from high to low concentration through membrane proteins without energy.

What is osmosis?

The diffusion of water across a selectively permeable membrane.

What is active transport?

Movement of substances against their concentration gradient using energy (ATP).

What is the difference between active and passive transport?

Active transport requires energy; passive transport does not.

What is endocytosis?

The process of bringing materials into a cell using vesicles.

What is exocytosis?

The process of releasing materials outside a cell using vesicles.

What is phagocytosis?

A type of endocytosis where a cell takes in large particles or solid materials.

What is pinocytosis?

A type of endocytosis where a cell takes in liquids and dissolved substances.

What is a vesicle?

A small membrane-bound sac that transports or stores substances.

What is a solute?

A substance dissolved in a liquid.

What is osmolarity?

The total concentration of dissolved particles in a solution.