Chapter 2

Cells

Section 1-Cell Structure

• Common cell structures– outer covering-_________________– internal gelatinlike cytoplasm– hereditary material

• Comparing cells-

Section 1-Cell Structure

• Two cell types

– Prokaryotic- __________membrane-bound internal structures

– Eukaryotic-___________membrane-bound internal structures

Section 1Cell Organization

• Composed of cellulose, a ___________ grows, changes shape, and protects the cells of plants, algae, fungi, and most bacteria.

• Cell __________-protective layer around all cells.– allows food and oxygen into the cell and

waste products out of the cell.

• _____________-gelatinlike substance inside the cell membrane.– ______________ scaffolding-like structure

in cytoplasm which helps cell keep its shape.

– Eukaryotic cells have ___________ which help with cell like processes.

Section 1Cell Organization

• ________________ contains instructions for everything a cell does; includes DNA

Section 1Cell Organization

CODE

Section 1Cell Organization

• Energy-processing organelles- help cells do their work– Green organelles in plant cells contain

____________ to make food.

– Organelles which release energy from food are called _______________.

green pigment=chlorophyll

Section 1 Cell Organization

• Manufacturing organelles

– ______________ make proteins for cell activities.

– Some ribosomes attach to the rough part of the endoplasmic reticulum.

Section 1 Cell Organization

• Transporting and storing organelles

– ______________move substances out of a cell or to other parts of a cell.

– ______________membrane-bound temporary storage space.

Section 1Cell Organization

• Recycling organelles

– _______________break down food molecules and cell waste.

Section 1 Cell to Organism

• Cells work together to keep an organism alive.– ________ group of similar cells working together on one job.

– Different types of tissues working together make up an _________.

– A group of organs working together on a particular function form a ___________.

lining inside mouth

kidney

heart, blood, and vessels

Section 2-Viewing Cells

• Magnifying Cells– Early microscopes- lenses made images

________, but not always clear.

Section 2Viewing Cells

• Modern microscopes- use lenses to bend light

– A simple microscope has one lens while a compound microscope has multiple lenses.

– A stereomicroscope, which has two eyepieces, creates a three-dimensional image.

– Powers of the eyepiece multiplied by objective lenses determine total magnification.

Section 2 Viewing Cells

• Electron microscopes- more powerful than other microscopes.– Use a _____________ in a vacuum to bend

electronic beams.– Images must be photographed or

produced electronically.

Section 2Viewing Cells

• Development of the cell theory– The cell theory resulted from many

scientists’ observations and conclusions.– The basic unit of organization is the cell.– All organisms are composed of one or

more cells.– New cells come from old cells through

cell division.

Section 3-Viruses

• ___________ - a nonliving strand of hereditary material surrounded by a protein coating.

• Virus multiplication- viruses can make copies of themselves only inside a living ___________ cell.– Active viruses make the host cell create

new viruses, which kills the host cell

Section 3Viruses

• 5 steps of active virus multiplication– virus attaches to host cell– hereditary material enters host cell– hereditary material causes the cell to

make viral hereditary material– new viruses form inside the host cell– viruses are released as the host cell

bursts

Section 3Viruses

– __________viruses hide in the host cell without destroying it.• virus hereditary material becomes part of

the host cell hereditary material• latent viruses can become active and then

destroy the host cells.

Section 3Viruses

• Viruses effects on organisms– most viruses infect only specific kinds of

cells– viruses are often carried to the host

through the air– the virus and host cell must fit together

exactly to begin a viral infection.– _____________attach to bacteria and

inject their hereditary material.

Section 3Viruses

• Fighting Viruses– __________- weakened virus particles

which allow the host to fight some diseases

Section 3Viruses

• Treating viral diseases– _______________ are not effective

treatments for viral infections– Infected cells sometimes produce

____________, which are proteins that can protect non-infected cells.

– Antiviral drugs often have adverse _____________, limiting their use.

– Public health measure can _________ or slow disease spread.

Section 3Viruses

• Research– ________________ uses viruses to replace

defective cell hereditary material with normal cell hereditary material.