1
What is the basic unit of life?
The cell.
What do we call an individual living thing?
An organism.
What do we call a group of similar cells working together to perform a function?
Tissue
How many cells do you think we have in the body?
30 trillion
What characteristic of life allows your body to remove waste products?
Excretion.
A fire can spread and grow, but fire is not alive. Give one reason why fire is not considered a living thing.
ire is not made of cells. It does not meet all the characteristics of life.
Arrange these from simplest to most complex: organ, organism, cell, organ system, tissue.
Cell → Tissue → Organ → Organ system → Organism
Cell → Tissue → ______ → Organ system → Organism.
What level of organization is missing?
Organ
Your body sweats when you get too hot. Which characteristic of life does this demonstrate?
Homeostasis — maintaining stable internal conditions.
Which one of these is alive?
-chair
-water
-cloud
-fungi
Fungi
How many organ systems do we have?
11
The stomach, small intestine, and other organs work together to break down food. What level of organization do they form?
Organ system
A plant grows toward a window where sunlight enters. Which characteristic of life does this demonstrate?
Response to stimuli.
Name one example of a living organism.
A plant, animal, fungus, or bacterium.
A robot moves, responds to commands, and uses energy from a battery. Why is it not considered a living organism?
It is not made of cells and does not carry out all the characteristics of life.
Heart muscle cells work together to form cardiac muscle tissue. Different tissues work together to form the heart. What are the two levels of organization described, in order?
Tissue, then organ.
A living organism takes in nutrients and breaks them down to obtain energy for its activities. What is this process called?
Metabolism.
seed appears inactive for months. When it receives water and the right temperature, it begins to grow. Is the seed alive? Explain your answer using one characteristic of life.
Yes. The seed is alive because it can grow and carry out life processes when conditions are suitabl
Why is reproduction important for the survival of a species, even though an individual organism can live without reproducing?
eproduction allows the species to continue across generations.
A student says that an organ system is less complex than an organ because it contains multiple organs. Is the student correct? Explain.
No. An organ system is more complex because multiple organs work together to perform a larger function.