Characteristics of Life
What is the smallest unit of life?
Cell
Why must slides be very thin when using a microscope?
→ So light can pass through and the image is clear
Which organelle is known as the “powerhouse of the cell”?
Mitochondria
Which tissue transports water and minerals in plants?
How many organ systems do we have?
11
Name one characteristic of living things.
→ Need energy / grow / reproduce / respond to environment / produce waste / made of cells
Who named “cells” after observing cork?
Robert Hooke
Which organelle controls what enters and leaves the cell?
Cell Membrane
Water enters plant roots by what process?
Osmosis
What is a tissue?
→ A group of similar cells working together
Why is a rock considered non-living?
→ It does not carry out all life processes (not made of cells, no growth, reproduction, etc.)
Why was magnification important to biology?
→ It allowed scientists to see cells and microscopic life
Which two organelles are found in plant cells but not animal cells?
Cell wall and Chloroplasts
Why are plant leaves flat and thin?
→ To increase surface area for gas exchange and sunlight
Put these in order from smallest to largest:
Cell, organ, tissue, organism, organ system
→ Cell → Tissue → Organ → Organ System → Organism
Why is producing waste important for living things?
→ Waste must be removed so cells can function properly
What is one difference between a simple microscope and a compound light microscope?
→ Compound microscopes use multiple lenses and can magnify much more
Which organelle packages and ships materials in the cell?
Golgi Apparatus
Which tissue transports sugars made in photosynthesis?
Phloem
Name the four main tissue types in humans.
→ Epithelial, connective, muscle, nervous
If something responds to its environment but cannot reproduce or grow, is it alive? Why or why not?
→ No — it must meet all characteristics of life
Who first observed single-celled organisms and called them “animalcules”?
→ Anton van Leeuwenhoek
Which organelles would be most active in a muscle cell? Why?
→ Mitochondria (energy) and ribosomes (protein production for contraction)
Where does photosynthesis take place and why is that organelle important?
→ Chloroplasts — they capture light energy to make glucose
Which three systems work together when you eat a slice of pizza? Explain briefly.
→ Digestive (breaks food down), muscular (chewing/swallowing), nervous (controls movement and signals)