Characteristics of Living Things
What is the basic unit of structure and function in all living things?
Cells
What 4 things do all living things need to survive?
Water, food, living space, stable internal conditions (homeostasis)
Which scientist used jars of meat to disprove spontaneous generation?
Francesco Redi
Define "Organism"
Any living thing.
Who developed the two-part naming system for organisms?
Carolus Linnaeus
What is it called when an organism keeps its internal conditions stable, like body temperature?
Homeostasis
What is an autotroph?
An organism that makes its own food.
In Redi’s experiment, which jar produced maggots—open or covered?
The open jar
What is a stimulus?
A change in the environment that causes a response
What is the two-part naming system called?
Binomial nomenclature
Give two examples of how organisms respond to stimuli.
A baby’s hand curls when touched, or pupils shrink in bright light
What is a heterotroph?
An organism that cannot make its own food, must consume other organisms.
Which scientist boiled broth in curved-neck flasks to disprove spontaneous generation?
Louis Pasteur
What is a response?
An action or change in behavior caused by a stimulus.
Give one example of how scientists classify organisms into groups
By shared characteristics, like structure or function.
What is the difference between unicellular and multicellular organisms?
Unicellular = one cell does all functions; Multicellular = many cells specialized to do different tasks
Why is water so important for cells?
Many chemical reactions in cells require water.
Why did the broth in Pasteur’s curved-neck flasks stay clear?
Bacteria could not get in from the air.
Define “species."
A group of similar organisms that can mate and produce fertile offspring.
About how many species of organisms are estimated on Earth?
8.7 million
List the 6 main characteristics of living things
Made of cells, contain chemicals, use energy, respond to surroundings, grow/develop, reproduce
Why do organisms compete for space?
Because resources like sunlight, minerals, or shelter can be limited.
What did both Redi’s and Pasteur’s experiments prove?
Life does not come from nonliving things (spontaneous generation is false)
What is spontaneous generation?
The mistaken idea that living things can come from nonliving sources
Why is classification important in biology?
It helps scientists organize and study the diversity of life.