Characteristics of Life
What is the smallest unit of life?
A cell
How many observations about cells were combined to form the cell theory?
Three.
1. All living things are made of cells
2. The cell is the smallest unit of life
3. All cells come from preexisting cells
What kind of cell has no nucleus and is not surrounded by a lining?
A prokaryotic cell
Which organelle is the "brain" of the cell?
Nucleus
What organelle do plants use for photosynthesis?
Chloroplasts
True or False: A robot that grows and uses energy is alive
False
What tool led to the discovery of cells?
The microscope
Name two organisms with eukaryotic cells
Plants, animals (humans), fungi, or protists.
What does the mitochondria do?
Produces energy (ATP). It is where chemical reactions of cellular respiration occur.
What structure helps plant cells keep their shape?
Cell wall
List the 6 characteristics of living things.
Made of cells
Uses energy
Grows and develops
Responds to stimuli
Maintains homeostasis
Reproduces
Why aren't viruses alive according to the cell theory?
Because they are not made of cells.
What is a key difference between eukaryotes and prokaryotes?
Eukaryotes have a nucleus and membrane-bound organelles (surrounded by a lining).
Prokaryotes do not.
Which organelle plays a role in protein production and may be “rough” or “smooth”?
Endoplasmic reticulum (ER)
Which two organelles are found only in plant cells?
Chloroplast and cell wall
How does a multicellular organism grow?
By increasing its number of cells through cell division
After Hooke's discovery of cells in 1665, why wasn't the cell theory developed until 1838?
Other scientists made observations about cells and improvements in microscopes were made during this time.
Are prokaryotes usually unicellular?
Yes
If a cell were a factory, what organelle would be the shipping department? (Hint: this organelle packages proteins into vesicles and transports them)
Golgi apparatus/ Golgi body
In plant cells, ________ carry out functions related to storage and support
Vacuoles
How do living things maintain homeostasis? Give an example.
By regulating internal conditions, e.g., sweating to cool down, blood sugar control, blood pressure regulation, fluid and electrolyte balance, gas exchange and pH balance, etc.
Light microscopes can enlarge images up to _______x their original size.
1,500x
How many prokaryotic cells could you fit inside one eukaryotic cell?
A. 10
B. 100
C. 1,000
D. 10,000
A. 10
How are ribosomes and the Golgi body connected?
Ribosomes make proteins; Golgi packages and ships them
Which material is most similar to a cell wall?
A. Wire mesh
B. Plastic bag
C. Cotton towel
A. Wire mesh
Like the cell wall, it is firm but allows movement of water and substances in and out. It provides structure, support, and helps maintain its shape.