BIO94 LECTURE 08.05.10 & 08.09.10

• -leaves have broad surface areas and high surface to volume ratios which increases photosynthesis
• -stomata is the site of water loss
• -stomata take in water by osmosis
• -stomata are open during the day and closed at night
• -warm water, saltier water hold less oxygen

• -oxygen is plentiful in air
• -gas exchange in air is less demanding than gas exchange in water
• -we have respiratory surfaces instead of stomata
• -respiratory surfaces take in oxygen by diffusion
• -respiratory surfaces are skins, gills, trachea, and lungs

• -gills increase surface area
• -red capillaries = oxygen rich
• -blue capillaries = oxygen poor

• -blood flows unidirectionally one way
• -water flows unidirectionally the other way
• -blood and water are COUNTERCURRENT
• -optimizes concentration of oxygen

-TRACHEA AND TRACHEOLES

• -birds have smaller lungs that contract & expand less than mammalian lungs
• -unidirectional air flow

• -either have a body shape that keep many or all cells in contact with the environment (porifera, cnidarians, flatworms) or USE A CIRCULATORY SYSTEM WITH FLUID THAT MOVE BETWEEN CELL'S SURROUNDINGS AND TISSUE WHERE GAS EXCHANGE OCCURS.
• -3 BASIC COMPONENTS: circulatory fluid, interconnecting tubes, and muscular pump
• -open circulatory system (no distinction between blood and interstitial fluid = hemolymph) --> arthropods & mollusks
• -closed circulatory system (blood confined to vessels) --> annelids, cephalopods, and all vertebrates

• -open circulatory system (no distinction between blood and interstitial fluid = hemolymph) --> arthropods & mollusks
• -closed circulatory system (blood confined to vessels) --> annelids, cephalopods, and all vertebrates

• -heart has 2 chambers: atrium and ventricle
• -blood leaving the heart passes thru two capillary beds before returning in gills and systemic capillary
• -seen in bony fishes, rays and sharks

-two circuits: left side of heart (systemic circuit = out of heart) and right side of heart (pulmonary circuit = to heart)

3 = two atria, one ventricle

3 = two atria, one ventricle with partial septum

4 = two atria, two ventricles

-the study of interactions of organisms with other organisms with the physical environment

• -variable that effects organisms
• -include all living organisms in area

• -variables that effect organisms
• -includes environment's non-living components such as temperature, energy, water, and nutrients

organisms within an area belonging to same species

various populations living together for potential interactions that includes all biotic factors in environment

community of populations which includes biotic and abiotic factors

NITROGEN and PHOSPHOROUS

• -the study of how and why populations change
• -important for pest control and saving endangered species

• (1) population density
• (2) dispersion pattern

• (1) clumped
• (2) uniform
• (3) random

• -most individuals survive well past the midpoint of the life span
• -usually produce few offspring
• -live past maturity
• -seen in humans of developed countries

• -populations where most die very young
• -produce larger number of offspring
• -seen in humans of less developed countries, invertebrates, and fish

• -survivorship decreases at constant rate throughout life span
• -seen in small mammals and birds

• -as population increases, the slope gets steeper
• -unregulated growth and reproduction
• -seen in populations introduced to new environments

• -populations grow exponentially for awhile but environmental factors limit growth
• -depends on species, resources available and abiotic factors

-abiotic factos that cause sudden reductions in population size

-biotic factors that effect population size such as PREDATION and PARASITISM