Upload
others
View
9
Download
0
Embed Size (px)
Citation preview
Crosscutting Concepts
1. Patterns2. Cause and Effect3. Scale, Proportion, and Quantity4. Systems and System Models5. Energy and Matter in Systems6. Structure and Function7. Stability and Change of Systems
Systems and System Models: A system is an organized group of related objects or components; models can be used for understanding and predicting the behavior of systems.
k-2: Objects and organisms can
be described in terms of their parts.
Systems in the natural world have parts that work together.
3-5: A system is a group of related
parts that make up a whole and can carry out functions its individual parts cannot.
A system can be described in terms of its components and their interactions
Structure and Function: The way an object is shaped or structured determines many of its properties and functions.
k-2: The shape and stability of
structures of natural and designed objects are related to their function(s).
3-5: Different materials have
different substructures, which can sometimes be observed.
Substructures have shapes and parts that serve functions
SKELETONS
Supporting structures for animalsProtect, support, enable movementSupport for movement and form in animals
4 typesEndoskeletonExoskeletonHydraulic skeletonCytoskeleton
How is a skeleton a system?
Has boundaries Has parts Parts work together
Function of skeletons
Support the body Shape of the body Enable movement Protection for internal organs Physiological functions
4 types of skeletons in animals
Endoskeleton Exoskeleton Hydraulic skeleton Cytoskeleton
Vertebrate skeleton• An endoskeleton – inside of the body • Functions:
– muscle attachment & movement– Protection of internal organs– Blood cell production– Calcium storage
• Living, mineralized tissue (cartilage & bone)
• Jointed• Two parts:
– axial – appendicular
All vertebrates have the same basic skeletal elements
Arms and Legs:How vertebrates move
Modifications of shape and size result in different function
Manatee
• Ribs and long bones have no marrow
• This helps them sink to bottom to feed
Exoskeletons
Stable outer shell• Found in arthropods• Made of chitin• Hard • Prevent dessication• Provide protection
Must shed exoskeleton to grow
Muscles attach on inside
• Insects and crustaceans have jointed appendages
• Muscles attach on inside surfaces of exoskeleton
Variation in size and shape provide for different functions
Hydrostatic skeletons in soft-bodied organisms
• Found in - Mollusks (e.g. snails, clams, slugs, octopus)- Worms- Tube feet of anemones
• Fluid filled cavities ringed with muscle
Movement in worms: how it worksCircular & longitudinal muscles
Elongate & contract body segments
Setae grip substrate
Jet propulsion
Japanese flying squid
Cytoskeletons –“movers and shapers”
• Proteins in form of microfilaments and microtubules in cytoplasm
• Form a 3-D meshwork• Dynamic – assemble and reassemble• Important for cell shape, movement of organelles
and materials in the cell, cell division, cell movement
• Motor proteins – cilia and flagella
Fluorescent dyes show filaments (red) and tubules (green)
Plant structural support
• Hold leaves (stems/trunk)
• Anchor to ground (roots)
• Require both flexibility and rigidity
How?
• Cell wall• Lignin• Cellulose• Wood
Cross Cutting concepts• Must observe parts before can understand them• Models are useful for studying structural systems• Understanding structure helps understand
function and vice versa• Function can be explained in terms of form and
form can be explained in terms of function• Structure and function are related through
natural selection• In biological organisms, structure is not always
optimal, but reflects the best solution available in a given lineage