Chapter 40 Flashcards
What challenges do all animals face?
- Obtain nutrients and oxygen
- Excrete wastes
- Reproduce
Why is there such diversity in animal form?
Natural selection
Natural selection
Individuals with adaptable heritable traits are more likely to survive and reproduce
Individuals with adaptable heritable traits are more likely to survive and reproduce
natural selection
What does natural selection result in a correlation of?
form (anatomy) to biological function (physiology) - form fits function
What affects the way animals interact with the environment?
Size and shape
Laws of physics govern what?
all aspects of body size and shape
- strength
- diffusion
- movement
- heat exchange
Fusiform body shape
tapered at both ends
Why do swimming animals have fusiform body shape?
To swim quickly
What do larger organisms require for support?
Thicker skeletons and more muscle
Larger body size –> more muscle –> …
limited mobility
What must animals exchange with their environment?
nutrients, waste products, and gases
Where does exchange occur?
across plasma membrane of each cell *each cell requires an aqueous environment
What is the rate of exchange proportional to?
membrane surface area
What has a direct effect on how the animal exchanges energy and materials with its surroundings?
Animal size and shape
What happens to surface area to volume ratio (SA:V) as animals get larger without changing shape?
SA:V decreases, resulting in less surface area to support chemical activity (metabolic needs/exchange)
How can organisms maximize surface area?
- flattening
- folding
- branching
- projections
How do simple body plans exchange with the environment?
- maximize exposure of cells to aqueous environment
- simple diffusion
- facilitated diffusion
How do complex body plans exchange with the environment?
increasing the number of cells decreases the other surface area to volume ratio
What would lower S:V mean?
materials can’t reach all parts of a cell quickly (can’t meet metabolic needs)
What do all cells of complex body plans need to be surrounded by?
interstitial fluid (fluid between cells)
How do complex organisms increase surface area for exchange
highly folded internal surfaces for exchanging materials
What do body fluids link in complex body plans?
exchange surfaces to cells
Exchange surface circulatory fluid … cells
interstitial fluid
Disadvantage of complex body plans?
more energy required for exchange
Benefits of complexity
specialized organ systems help maintain homeostasis in a variable external environment
Four types of tissues in animals
- Epithelial
- Connective
- Muscle
- Nervous
Epithelial Tissue form
sheets of tightly packed cells, apical and basal surface
Apical Surface
free surface exposed to fluid or air
Basal surface
attached to connective tissue
Epithelial tissue function
outside covering, lines organs and body cavities, secretion/absorption
outside covering
barrier against mechanical injury, microbes, fluid loss
Epithelium tissue shapes
- Cuboidal
- Columnar
- Squamous