Transcript Chapter 8: Life`s structure and Classification

Chapter 8: Life’s structure and
Classification
Living Things
What are living things like?
• Organism: Any living thing
• Can vary in size (bacteria---gigantic oak tree---humans)
• Have different behaviors and food
requirements
Similarities between all living things
• They are organized
• All organisms are made up of cells (the smallest unit of an
organism that carries on the function of life)
• They grow and develop
• Infant—adult
• Organisms change as they grow (development)
• They respond
• Living things must interact with their environment
• Stimulus: Anything that causes some change in an
organism.
• Response: the reaction to a stimulus-Results in
movement
Similarities between all living things
(continued..)
• They maintain homeostasis
• Ability of an organism to maintain proper internal conditions
despite changes in the environment.
• They use energy
• All organisms require energy for everyday life functions (staying
organized, carrying on activities-finding/making food)
• They reproduce
• Making their own kind
• Living things need to replace those individuals that die
What do living things need?
• A place to live
• Suited to their unique needs (temperature,
sunlight, space etc..)
• Water
• Important functions: transporting materials within
a cell and between cells.
• We are made up of 60-70% of water!
• Food sources
• Take in substances (protein, fats, sugars) from other
animals
• Plants and some bacteria make their own food
Cell Structure
-What are cells?
-What are the functions of each part of
a cell?
- What is the difference between
unicellular and multi-cellular
organisms?
A little history
• 1600’s : Leeuwenhoek made a simple
microscopeled to types of microscopes we use
today
• Discovered cells under microscope
– Robert Hooke looked at a cork and saw many empty
little boxes—named them cells
• 1800’s: Schleiden(plant cell) and Schwann (animal
cell): all living things are made up of cells
• Virchow: main contributor to the cell theory
The Cell Theory
• All organisms are made up
of one or more cell
• The cell is the basic unit of
organization in organisms
– Basic unit of structure and
function
• All cells come from cells
– Divide to form new, identical
cells
Prokaryotic vs Eukaryotic Cell
• Prokaryotic: only found in ONEcelled organisms
– Cells without membrane-bound
structures
– Ex: Bacteria
• Eukaryotic:
– More complex internal structure
– Cells with membrane bound
structures
– Ex: protists, fungi, plants and
animals
Prokaryote vs Eukaryote
Cellular organization
- Main structures
Organelle: parts of the cell
Just Plant
Cell
Both Plant and
Animal Cell
Just Animal
Cell
Cell wall
Cell membrane
Centrioles
Chloroplasts
Cytoplasm
Cytoskeleton
Nucleus
Mitochondria
Golgi
Vacuole
Endoplasmic reticulum
Ribosome
(Lysosome)
•
Cell Membrane
–
–
Protective layer surrounding every cell
Regulates interactions (what goes in and out) between the cell and its
environment
•
•
•
Cell structure
Description/function
Nutrients move in, waste moves out
Cytoplasm
–
–
–
Gelatin like substance which cells are filled with
Where the cells organelles are located
Most of cells life processes occur here
Nucleus
–
–
contains a membrane, nucleolus, and hereditary material (DNA)
Control center(all cellular activities are directed here)
Image Bank
Eukaryotic
Cell
Membrane
Cell structure
Description/function continued
• Mitochondria
– Powerhouse of the cell-releases energy
that is needed by the cell
• Golgi bodies
– Stacked flattened membranes
– Package material for release to the
outside of the cell
• Vacuole
– Membrane-bound spaces
– Temporary storage of materials (stores
water, waste products, food etc.)
Cell structure
Description/function continued
• Endoplasmic reticulum (ER)
– Series of folded membranes
– Transport materials inside cell
• Ribosomes
– Make proteins
Proteins: part of cell membranes and
needed for chemical reactions that take
place in the cytoplasm
• Chloroplasts (plant only)
– Contains chlorophyll
Use light to make sugar-food and energy for
plants
Cell structure/function
• Lysosome
• Break down & Recycle!
• Contain digestive chemicals
that break down food
molecules, cell wastes, worn
out cell parts and viruses
and bacteria that enter cell
• When cell dies, release
chemicals to breakdown cell
contents
Animal vs Plant Cell
Unicellular vs Multicellular organisms
• Unicellular organism:
– one celled organism (perform all life functions on their
own)
• Multicellular organisms:
– many celled organisms (cells cannot function alone)
– Celltissueorganorgan systemsorganism
Image Bank
Many-Celled
Organism