Characteristics of Life
What is the basic unit of life?
Cell
Put these in order from simplest to most complex: tissue, cell, organ, organ system, organism.
Cell → Tissue → Organ → Organ System → Organism
What type of cell helps muscles contract?
Muscle cells.
What does biotic mean?
Living or once living
What is an environment?
Everything surrounding an organism that can affect its survival.
Name three characteristics all living things share.
Made of cells, need energy, grow and develop, reproduce, respond to environment, maintain homeostasis, set organization (any three).
What is a tissue?
A group of similar cells working together to perform a function.
Which cells transport oxygen in the body?
Red blood cells.
Give two examples of abiotic factors.
Water, sunlight, temperature, soil, rocks, air (any two).
Give an example of how an organism interacts with its environment.
Plant bends toward sunlight; deer eats plants; fish needs water.
What is homeostasis?
Maintaining stable internal conditions even when the environment changes.
What level of organization is the heart?
Organ
Name one specialized structure in plant cells and its function.
Chloroplasts—capture energy from sunlight.
Is a fallen log biotic or abiotic?
Biotic (it was once living).
What environmental factor causes a plant to grow toward a window?
Sunlight.
Give an example of a stimulus and a response in a living thing.
Touching a hot stove (stimulus) → pulling hand away (response).
What is a population?
Members of the same species living in the same area.
Do all cells perform the same task? Explain.
No, different cells have specialized functions.
Why are abiotic factors important in an ecosystem?
They affect survival and interactions of organisms (e.g., water and sunlight needed for life).
What might cause a fish population to decrease if the pond becomes polluted?
Water quality (abiotic factor).
If an organism does not reproduce, is it considered alive? Explain.
Yes, an individual can be alive even if it doesn’t reproduce; reproduction is a characteristic of the species.
What’s the difference between a community and an ecosystem?
A community is all living populations in an area; an ecosystem includes the community plus nonliving (abiotic) factors.
What is the function of nervous tissue?
To communicate information throughout the body.
True or False: A fire is alive because it grows. Explain
False: Not made of cells, cannot reproduce etc.
Name two ways beavers can change their environment and how.
Build dams (change water flow), create ponds (affect habitats).