Bell Work and Seating Chart 5th Period

Row 1 Row 2 Row 3 Row 4 Row 5

Keldrick Brown Velma Frierson Dustin Brooks Joseph Anderson Antonio Carter

Brandon Boyd Michael Edmonds Christian McDaniel

Tierra Morton Breanna Collins

Romanda Smith Kelsey Harris Bernard Luckett Jonathan Miller Kendrick Palmer

Cierra Watts Nicole Gainwell Jalena Allen Herbert Moorehead

Ashley Shiers

Ebony Jones Bobby Isonhood William Hancock ReShawnna Banks Brittany Moseley

What does this symbol mean? What should you do if you see it?

Bell Work and Seating Chart 6th Period

Row 1 Row 2 Row 3 Row 4 Row 5Rocky Ross TJ Hasty Jonathan

BarnetteBrandy King Peyton

CarltonLuis Esparza Jordan Perry Cody Coghlan Kristen Foster Rothelio

SandersWes Duchesne Shanita

HortonChristopher Campbell

Haleigh Douglas

Cameron Bell

Yasmine Carter

Skylar Purvis Katie Fennell Shamika Horton

Raney Page

Kebrianna Granderson

Tyler Mullins Mary Bell Kayla Jenkins

What does this symbol mean? What should you do if you see it?

Classroom Rules Review

Intro to Biology – Lecture 33

Introduction to Cells

What is a Cell?

A Cell

• the basic unit of structure in every living thing

Discovering the Cell

• The cell was discovered by Robert Hooke in 1665.

• He examined (under a coarse, compound microscope) very thin slices of cork and saw a multitude of tiny pores.

Problems with Hooke

• He did not know the cell’s structure or function.

• He saw no nucleus or other organelles found in most living cells.

• The cells he looked at were actually non-living cell walls.

Finding a Live Cell

• The first to witness a live cell under a microscope was Anton van Leeuwenhoek.

Discovering the Importance of Cells

• The idea that cells were separable into individual units was proposed by Ludolph Christian Treviranus and Johann Jacob Paul Moldenhawer

• This led Henri Dutrochet to conclude "The cell is the fundamental element of organization".

• This led to cell theory.

Cell Theory

• All living organisms are composed of cells. They may be unicellular or multicellular.

• The cell is the basic unit of life.• Cells arise from pre-existing cells.

Modern Cell Theory

• Energy flow occurs within cells.• Heredity information (DNA) is passed on from

cell to cell.• All cells have the same basic chemical

composition.

Who Came Up With Cell Theory?

• Theodor Schwann• Matthias Schleiden• Rudolph Virchow.

Cell Theory

• The cell theory holds true for all living things, no matter how big or small.

• Since cells are common to all living things, they can provide information about all life.

Studying Cells

• And because all cells come from other cells, scientists can study cells to learn about growth, reproduction, and all other functions that living things perform.

• By learning about cells and how they function, you can learn about all types of living things.

If Cells Come from Other Cells, Where did the First Cells Come From?

If Cells Come from Other Cells, Where did the First Cells Come From?

• One theory of the origins of cells states that the first life on earth consisted of several types of tiny protocells, cell-like organisms.

How did they change?

• These organisms were able to survive and reproduce in a very limited environment because of their simplicity.

When did They Become Cells?

• Over time, some of these protocells came together and shared their specialization in a symbiotic relationship.

• These colonies of protocells eventually became the cells we know today.

Pop Quiz

• What are the 3 MAIN classroom rules we talked about at the beginning of class today?