Regents Biology

7.1 – Life Is Cellular

Regents Biology

§  In 1665, Robert Hooke looked at cork bark in an early compound microscope.

§  He saw small structures that looked like “cells” in a monastery

Hooke

Regents Biology

§  In 1674, Antoine van Leeuwenhoek discovered microscopic organisms.

§  He saw small organisms swimming in pond water, and called them “animalcules.”

Leeuwenhoek

Regents Biology

Chapter 3: Cells

1852 1838

Regents Biology

•  Schlieden and Schwann determined that both plants and animals are made of cells.

•  Schwann introduced the Cell Theory in 1839

•  In 1855, the Cell Theory was corrected and refined after studying how cells divide.

Schleiden and Schwann

Regents Biology

Cell Imaging Timeline

Regents Biology

1.  All organisms are made of one or more cells.

2.  All existing cells are produced by other living cells.

3.  The cell is the most basic unit of life.

Chapter 3: Cells Section 1: Cell Theory Cell Theory

Regents Biology

There are two different types of cells

§  Prokaryotic §  Eukaryotic

§  “Pro” = “Before” §  “Karyon” = “Nucleus”

Chapter 3: Cells Section 1: Cell Theory Cell Types

Regents Biology

§  extremely small (just a few μm)

§  no nucleus §  no organelles §  all single-celled §  make up the

domains Bacteria and Archea

Chapter 3: Cells Section 1: Cell Theory Prokaryotes

Regents Biology

Regents Biology

Chapter 3: Cells Section 1: Cell Theory

Regents Biology

§  relatively large ( ) §  have a nucleus §  have organelles §  can be single- or

multi-cellular §  make up the domain

Eukarya (Fungi, Plants, and Animals)

Chapter 3: Cells Section 1: Cell Theory Eukaryotes

Regents Biology

Chapter 3: Cells Section 1: Cell Theory