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Natural Selection
Best adapted survives and reproduces!
English Peppered MothExample
Before industrial revolution After industrial revolution
English Peppered Moth Example
Galapagos Ground FinchStudy by Rosemary and Peter Grant
In dry years average beak depth increases-birds with large bills survive better-more large seeds available
In wet years average beak depth decreases-birds with small bills survive better-more small seeds available
Antibiotic Resistance
• Antibiotic resistance happens fast!• Antibiotics: chemicals that destroy
microorganisms like bacteria• Genetic variation = bacteria are not all the same• Selective pressure for resistance = bacteria that
are resistant survive and their offspring survive• Resistance comes from: 1. inappropriate use
2. patients who do not take whole prescription• Antibiotic use in livestock: 1. used in healthy
animals 2. causes resistant bacteria
Antibiotic resistant gene
Bacteria with antibiotic resistant gene survive
AND REPRODUCE THE NEXT GENERATION!!
Properties of Water: Cohesion and Adhesion
Cohesion: holds water together within a vesselAdhesion: water sticks to vessel wall resisting gravity
High Surface Tension
Properties of water:(Due to hydrogen bonding)
• Cohesion/Adhesion
• High surface tension
• High specific heat
• High heat of vaporization
• Lower density as a solid than a liquid
• Good solvent
Solute + Solvent = Solution
Acids, Bases and Buffers
Acid: high H+
Base: low H+
pH: measure of H+
Acid Rain:Destroys Lakes
Buildings and Statues
Ocean Acidification
• Overproduction of carbon dioxide through fossil fuel combustion
• Oceans absorb carbon dioxide
• Ocean acidification: CO2 dissolves in seawater and reacts with water to form carbonic acid (lowers ocean pH)
• Less carbonate for reef calcification
CO2 dissolved in ocean reacts with water to form carbonic acid
Carbonic acid dissociates into bicarbonate and hydrogen ions
Hydrogen ions form more bicarbonate with carbonate ions making them unavailable for calcification by marine animals such as coral
Coral reefs increase biodiversity,protect shorelines, feeding ground for fish species (fisheries), tourism
Succulent = stores water
Connection between photosynthesis andcellular respiration
Strategies for Body Temperature
• Endotherm: most body heat obtained internally (from metabolism)
• Endotherms tend to be homeotherms (maintain a constant body temperature)
• Ectotherms: most body heat obtained externally (from environment)
• Ectotherms tend to be poikilotherms (allow body temperature to fluctuate with environmental temperature)
Modes of Heat Loss and Gain
Radiation: heat loss or gain by a difference in body temperature and the environmentConduction: heat loss or gain by direct contact with an objectConvection: heat loss or gain by wind or water currentsEvaporation: heat loss only, cooling mechanism
Body Temp = Heat Produced + Heat Gained – Heat Lost
(By Metabolism) (From Environment) (To Environment)
Osmoregulation: salt and water balance
What does osmoregulation for us?
Special adaptations: Kangaroo rats
Excretion of nitrogenous wastes