Introduction to Cells

Introduction to Cells

Microscopes make small objects look larger. After microscopes were invented, cells were discovered.

• Compound light microscopes have more than one lens.

• Electron microscopes use electrons to create an image that has very good magnification and resolution.

Multiple Choice

__________ refers to the sharpness of an image and how clearly the individual parts of the specimen can be seen.

• total magnification

• resolution

• magnification

Multiple Choice

The ability to make things look larger than they are is called

• magnification

• resolution

Multiple Choice

To calculate ________________ multiply the magnification of the eyepiece lens with the magnification of the objective lens.

• resolution

• convex lens

• total magnification

The Cell Theory States

• All living things are made of cells.

• Cells are the basic unit of structure and function in living things.

• Living cells can only come from other living cells.

Robert Hooke

Robert Hook coined the term "cells" because he was reminded of monk cells when he observed cork under the microscope. He was observing the cell walls of the cork oak tree and was one of the first people to see cells.

Anton van Leeuwenhoek

Anton van Leeuwenhoek looked at teeth scrapings and pond water under the microscope. He was the first to see living cells and called the organisms "animalcules." We now know he was observing bacteria and unicellular protists.

Matthias Schleiden

Matthias Schleiden was a botanist who studied plant parts under the microscope and determined that all plants are made of cells.

Theodore Schwann

Theodore Schwann studied animals and determined that all animals are made of cells. This statement was later broadened to say that all living things are made of cells.

Rudolf Virchow

Rudolf Virchow stated that living cells can only come from other living cells.

Multiple Select

Check on all correct cell theory statements.

• All living things are made of cells.

• Atoms are the basic unit of structure and function in living things.

• Cells are the basic unit of structure and function in living things.

• Living cells can only come from other living cells.

Multiple Choice

Which scientists stated that all plants are made of cells?

• Leeuvenhoeke

• Schwann

• Hooke

• Schleiden

Multiple Choice

Which scientists was the first to see living cells?

• Hooke

• Leeuwenhoeke

• Schleiden

• Schwann

Multiple Choice

Which scientists said living cells must come from other living cells?

• Virchow

• Schwann

• Hooke

• Schleiden

Multiple Choice

Which scientists said all animals are made of cells?

• Leeuwenhoeke

• Schleiden

• Schwann

• Hooke

Multiple Choice

Who was the first person to see cells?

• Leeuwenhoeke

• Hooke

• Virchow

• Schwann

Cell Organelles and Functions

An organelle is a structure in cells that has a particular job.

Nucleus

• Controls the cell's functions

• Contains DNA

• Is like the mayor of a city

Nucleolus

• Located inside the nucleus

• Makes ribosomes

• Is like a factory in a city

Mitochondria

• Located throughout the cytoplasm

• Breaks down food to release energy in a process called cellular respiration and is nicknamed the "powerhouse"

• Is like the power plant for the city

Cytoplasm

• Jelly like substance that surrounds the organelles

• Makes it easier for molecules to travel within the cell

• Is like the landscaping of the city

Ribosomes

• Located both in the cytoplasm and on the ER

• Makes protein

• Is like a construction worker for the cell

Vacuoles

• Plant cells have one large central vacuole

• Animal cells have several small vacuoles

• Vacuoles store water, food, and waste

• The vacuole is like a warehouse for the city

Endoplasmic Reticulum

• Located close to the nucleus

• ER for short

• Materials travel through this tube-like structure

• Is like a road in the city

Cell Membrane

• Surrounds the cell

• Controls what goes in and out of the cell through numerous pores

• Is like a fence around the city park

Cell Wall

• Is the outermost layer of plant cells

• Provides support and protection for the cell

• Is like a wall around a city

Chloroplast

• Located throughout the cytoplasm of plant cells

• Contains the green pigment chlorophyll

• Captures radiant energy from the sun and converts it to chemical energy for the cell to use in a process called photosynthesis

• Is like solar panels that produce electricity for the city

Lysosome

• Found throughout the cytoplasm of animal cells

• Contains enzymes that break down old cell parts and food

• Is like the recycling center of the city

Chromatin

• Located in the nucleus of the cell

• Contains genetic material in stringlike form

• Contains directions for the cell's functions and characteristics

• Is like a blueprint for a building

Multiple Choice

Which organelle is like a road through which materials can travel?

• nucleus

• ER

• cytoplasm

• mitochondria

Multiple Select

Which organelles are found in plant cells but not animal cells?

• cytoplasm

• cell wall

• cell membrane

• chloroplasts

Multiple Choice

What is the jelly like material that surrounds the organelles?

• cytoplasm

• chlorophyll

• chloroplasts

• cell membrane

Multiple Choice

Which structure provides support and protection for plant cells?

• cell wall

• cell membrane

Multiple Choice

What does the nucleolus make?

• ER

• ribosomes

• vacuoles

Multiple Choice

Which structure controls what goes in and out of both plant and animal cells?

• cell wall

• cell membrane

Multiple Choice

Which structure is the nicknamed the "powerhouse" of the cell because it produces energy for the cell?

• mitochondria

• chloroplasts