Classifying Living Things
What tool is used to identify organisms by answering yes-or-no questions?
Dichotomous key
How many centimeters are in 1 meter?
100 cm
What process do plants use to make their own food?
Photosynthesis
Which organelle controls the cell’s activities?
Nucleus
A plant cell lacks sunlight for several days. Explain how this affects its survival.
Without sunlight, it cannot perform photosynthesis, so it cannot make food and will eventually die
Name one thing all living organisms must be able to do to be considered living.
Grow, reproduce, use energy, respond to stimuli, or be made of cells
How many millimeters are in 1 centimeter?
10 mm
Which organelle is known as the powerhouse of the cell?
Mitochondria
Which organelle makes proteins for the cell?
Ribosomes
A scientist measures the length of a desk as 1,250 millimeters. Convert this to meters.
1.25 meters
If an organism can make its own food using sunlight, how is it classified?
Producer (autotroph)
Convert 2 meters into centimeters.
200 cm
Which cell membrane process allows oxygen to move into a cell without using energy?
Diffusion
Which organelle packages and ships proteins?
Golgi apparatus
A cell membrane allows some substances in and keeps others out. Explain why this selective transport is important for the cell’s survival.
It maintains the right balance of water, nutrients, and ions inside the cell, preventing damage and allowing the cell to function properly
Which characteristic separates living organisms from nonliving things like rocks?
Ability to reproduce, grow, or carry out life processes
A runner jogs 1.5 kilometers. How many meters did the runner jog?
1,500 meters
Why do cells need cellular respiration even if they get energy from food?
To release usable energy (ATP) from food
If a cell has plenty of energy but can’t make proteins, which organelle might be damaged and why?
Ribosomes; because they are responsible for building proteins
A scientist observes two animals that look very different but have very similar DNA. What does this suggest about their classification?
They are closely related and likely belong to the same family
Why is a virus difficult to classify as living?
It cannot reproduce or carry out life processes on its own
A bottle holds 750 milliliters of water. How many liters of water is that?
0.75 liters
A cell is placed in a very salty solution. What will happen to the cell and why?
Water will leave the cell by osmosis, causing it to shrink
How do organelles work together to produce and release a protein outside the cell?
The nucleus gives instructions, ribosomes make the protein, the ER folds it, and the Golgi apparatus packages and ships it
A cell uses active transport to move ions from low to high concentration. Explain why this process requires energy and why it’s important.
Moving ions against their concentration gradient requires energy (ATP); it’s important to maintain proper cell function, balance, and survival