Semester Review
Weathering and erosion
• Oxidation, acid rain and living organisms are all agents of _______________ weathering.chemical
oxidation Limestone caverns form
through central Texas Sink holes form when caverns collapse
Weathering and erosion
• Freezing and thawing, animal actions and abrasion are all agents of __________
weathering.
mechanical
Freezing and thawing Abrasion formed these arches in the Arches national park in Utah
Biodiversity
• What is biodiversity?
Biodiversity is the variety of life in an ecosystem.
• Variety in species
• Of species
• Of ecosystems
Why biodiversity is important
• Biodiversity provides stability in and ecosystem
• It provides a variety of food sources
• It provides a variety of habitats
• It creates and an environment that is less susceptible to disaster or disease
What is sustainability?
• It is the ability of an ecosystem to continue to flourish despite stress.
• High biodiversity= high sustainability
• Low biodiversity= Low sustainability
What makes and ecosystem more stable?
More Links in the food chain If something wipes out
one particular species it doesn’t cause the ecosystem to collapse.
Protecting watersheds
Buildings and parking lots:
• Prevent water from entering the groundwater (aquifer)supply
• Increase runoff
(fertilizers, chemicals etc) Into surface water
Well usage
Adding homes, buildings and parking lots would decrease the amount of water available in the aquifer and increase the amount of run off of
fertilizers, oil etc.
Adding a well in any area is going to decrease the amount of water in the aquifer
Here’s our well
Groundwater erosion
This is a picture of Inner space Caverns in Georgetown this is a natural formation. Much of central Texas has limestone rock layers beneath the surface. This rock weathers chemically when carbonic acid seeps through forming openings beneath the surface over thousands of years.
Autotrophs vs. heterotrophs
Autotrophs make their own food through the process of
photosynthesis
Heterotrophs are consumers
What do all of these organisms have in What do all of these organisms have in
common?
common?
Cell Theory
• All organisms are composed of cells
• Cells are the basic unit of structure for all living things
• Cells come from other living cells
Characteristics of living things
(energy)
Structure vs. function
Structure- how something is made
Ex: A plant cell has a rigid cell wall.
Function what it does
Ex: The cell wall of a plant cells provides support for the plant.
Turgor pressure
Turgor pressure is the Turgor pressure is the
pressure of a vacuole pressure of a vacuole
full of water on the cell full of water on the cell
wall causing a plant to wall causing a plant to
be firm or rigid.
be firm or rigid.
A plant that is wilted lacks turgor pressure.
Forces a seedling must overcome
1. Seed Coat (outer covering of the seed) 2. Soil
Water absorbed by the seed increases turgor pressure, breaking open
The seed coat and allowing The plant to begin pushing through the soil
The upward growth of the plant
Is due to it’s response to gravity (geotropism)
Levels of organization
Sexual vs. Asexual reproduction
• Sexual reproduction
– Two parents
(combination of genes) – Offspring not identical to
parent
– Few offspring – Genetic diversity
• Asexual reproduction
– One parent (one gene set)
– Offspring identical to parent
– Many offspring
– Little genetic diveristy
• Binary fission- to split apart Ex. cells
• budding- buds grow from parent
Ex. Hydra
Or potato
• Vegetative propagation- new plant grows from sprouts of existing plant
Ex. Strawberry plant
• Regeneration- a new organism developing from a part separated from the parent
Ex. Starfish
Definitions
• Genotype= genetic make up
• Phenotype= physical appearance
• Purebred= alleles same (hh or HH)
• Hybrid= alleles different (Hh)
• Trait= characteristic passed from parent to child
Purebred Dominant
• Dominant
– Always shows up – (Hh or HH)
• Recessive
– Only can show if two recessive genes are present (hh)
Where is DNA found?
• Genetic material is found on chromosomes in the nucleus of the cell.
Prokaryote vs. Eukaryote cells
• Both parents are hybrid. 75% offsrpint will have brown and 25% will have blonde hair
B b
B BB Bb
b Bb bb
Trait
A physical characteristic passed on from parent to offspring. Ex. Hair color, eye color etc.
Alleles
• Different versions of a trait
• You have two alleles for each trait
• One from mom and one from dad
Free earlobes?
Free earl lobes must be dominant if one allele for free and one allele for attached was passed on to offspring.
If a trait is recessive the only way the recessive traits shows up if two reccessive forms of the gene are passed to the offspring.
Plant vs. animal cells
Natural selection
• Organisms better adapted to their
environment reproduce and pass on their favorable traits, changing the variety of species over time. (survival of the fittest)
These finches evolved different beaks due to the types of food available
Larger beaks were more frequent in times of
drought.
Selective breeding
Intentional breeding for favorable traits
Alveoli-air sacs in lungs gas exchange
• Carbon dioxide is
exchanged for oxygen to be distributed to the
body by the circulatory system.
Villi in the small intestine provide the nutrients for the circulatory
system to deliver to other part of the body.
Digestive system + circulatory system
(Carbs.)
Octobr 8, 2012
Ms. Smith Mrs. Malone
:
Chemical changes is when matter has changed into a new substance through a chemical reaction.
color change
formation of a gas
light production
smoke
presence of heat
Precipitate forms
Chemical Mechanical to Thermal
Maintaining homeostasis
Simple machines change the
direction or
amount of force but does not
change the
amount of work
Work is being done to lift the object a distance
No work is being done when
pushing a brick wall and it doesn’t move
Which requires more work?
A B
5ft 10ft
Answer: B. B will require more work because the object is being lifted a
greater distance. (If the boxes were the same height and only the steepness changes, then the same amount of work would be done because the force changes.
Less force less distance
More force (steeper) more distance
(higher)
With these two ramps work would be the same
A B
5ft 5ft
More force less distance Less force more distance
Describe the stages of primary succession.
• Bare rock (no life exists) weathering of rock
• Lichen and moss help weather rock
• Soil is formed
• Grasses and weeds
• Small shrubs and trees and smaller plants begin to die out
• Trees reach maturity
• Climax community
Describe the stages of secondary succession.
• A disturbance occurs leaving bare soil
• Grasses and weeds
• Small shrubs and trees and smaller plants begin to die out
• Trees reach maturity
• Climax community
Dichotomous Key
• What is a dichotomous key? A dichotomous key is one tool that can be used to identify
trees. This type of key is also used for flowers, animals, rocks, fish, and more!
• A dichotomous key contains a series of choices that lead the user to the correct name of an
item. "Dichotomous" means "divided into two parts." Therefore, a dichotomous key will
always give you two choices in each step.
• 1a If the object is organic go to 2
• 1b If the object is inorganic go to 3
• 2a If the object is a plant- ivy
• 2b If the object is not a plant- Red Belly Toad
• 3a If the object is round – ball
• 3b If the object is not round - stapler
Reading a Dichotomous Key
How many questions in a dichotomous key?
• There are as many questions in a dichotomous key as there are items to identify.
• Some keys can be short and some are very long.
