Biology 8.1

All living things are made up of

cells

Cells are the basic units of ___ and ___ in living things

structure, function

New cells are produced from

existing cells

What is the cell theory?

1. All living things are made up of cells 2. Cells are the basic unit of structure and function 3. New cells are produced from existing cells

The cell theory is based off of who?

Schleiden, Schwann, Virchow

A well-tested explanation that unifies a broad range of observations and hypotheses and enables scientists to make accurate predictions about new situations

Definition of theory

What instrument allowed scientists to discover cells

microscopes

A compound light microscopes use what type of beams to produce magnified images

light beams

What type of beams do electron microscopes use to produce magnified images

electron beams

For an electron microscope what is needed to study the cells

The slice needs to be in a vacuum

What type of image do scanning electron microscopes produce

3D

Scanning electron microscopes look at the ___ of a specimen

surface

Transmission electron microscopes look at the ___ of a specimen

inside

What type of image do TEM's produce

2D/ flat

what help scientists see the movement of compounds and structure in living cells

Fluorescent dyes

What type of microscope would you use to see living cells and tissues

Light microscope

What microscope magnifies to about 1000x

Light microscope

What microscopes images are limited

Light microscope

What type of microscope(s) use beams of electrons

scanning and transmission

What microscope would you use to see the inside/structure of a thin slice of a cell

transmission

What microscopes are best to see smaller cells

Electron microscopes

Differences between SEM and TEM

1. scanning is 3D/ transmission is 2D 2. Scanning doesn't need to be in thin slices/ transmission needs to be in thin slices 3. Scanning you can see the surface/ transmission you can see the inside of a cell

What's an advantage of using a light microscope over an electron microscope

In a light microscope, you can look at living cells and tissues and how they move while in an electron microscope you can only observe dead cells and tissues

Who was the first to use a microscope to observe cells in a slice of cork

Hooke

Who was famous for observing "animalcules" in pond water and dental scrapings

Leeuwenhoek

Who concluded that all animals are made of cells

Schwann

Who concluded that all plants are made of cells

Schleiden

Who concluded that all cells come from pre-existing cells

Virchow

List the scientists in chronological order from earliest to latest

Hooke(1665), Leeuwenhoek(1665), Schleiden(1838), Schwann(1839), Virchow(1855)

Definition of Prokaryotic cell

A cell that does not enclose DNA in a nucleus (doesn't have a nucleus) and doesn't contain membrane bound organelles

Definition of Eukaryotic cells

A cell that encloses DNA inside a nucleus. Also contains membrane bound organelles

Examples of prokaryotes

Bacteria and Archaea

Examples of Eukaryotes

fungi, animals, protists, plants

prokaryotes are ___ and ___

smaller and simpler

eukaryotes are ___ and ___

larger and more complex

If a student wants to see a cell in 3D, which microscope would they use?

SEM (images are in 3D)

If a researcher wants to analyze and observe the arrangement of organelles inside a cell, which microscope would they use

TEM (images are of the inside of a cell showing the structure of it)

Why is the cell theory a scientific theory rather than a guess

It's made up of 3 different well-tested explanations regarding cells. The 3 ideas from different people group together to create one theory to help scientists create predictions about new situations