biology eoc review session. biology eoc 5-6 scenarios 40 questions total 40-45% cells, genetics,...
TRANSCRIPT
Biology EOC Review Session
Test-taking Tips
Go SLOWLY.
Take your time, READ everything.
Look at the pictures, charts and graphs…they are there for a reason.
Pay attention to words in bold or italics. They are often clues to help you with the answer.
Vocabulary
Variables Manipulated, responding, control
Validity What you did during the experiment
(procedure) to obtain good data (NOT repeating, recording, calculating or measuring) making sure equipment is calibrated correctly for example.
Reliability Repeat the experiment, multiple trials, obtain
more data using same procedure Making sure you have consistent results
Hypothesis
If… then… because… format(mv) (rv) (rationale)
Most importantly you have to include a reason for your statement.
“Foaming Spuds”
Conclusion writing practice 1. Answer the investigative question
Was your hypothesis supported/rejected and why
2. Include supporting data from entire range of experiment (high and low)
3. Explain how data supports or rejects your answer to investigative question
4. Use scientific explanation to explain results/trends
“Foaming Spuds” Procedure Re-write
Create a procedure for a new variable that is being tested.
Tips when re-writing a procedure… Procedure steps are logical and can be easily repeated
by another person Variables are identified/implied
Two controls Manipulated and Responding variable
Procedure includes information about recording measurements
Information about repeating trials is included Includes a validity measure not included in original
procedure…
Field Study Scenario
Include method for collecting data Imply a consistent sampling strategy
“count at the same time every day” Identify one manipulated variable
Three conditions to be credited (3 areas) Identify one responding variable
What is being measured Record measurements / environmental conditions
How often, specific technique for recording measurements Repeat trials
Multiple measurements, 2 sampling areas Record environmental conditions
Temperature, weather, etc. Steps of procedure are logical
Research Ideas
Possible Solutions Constraints (excluding cost)
Overview of Concepts
Here is a quick review of all of the concepts that we’ve gone over through the course of the year.
Macromolecules
“Giant Molecules” (polymers)Linked together with smaller subunits (monomers) Carbohydrates Proteins Fats (lipids) Nucleic acids
Carbohydrates
Compounds made of CHO Monomer = monosaccharides Main source of energy for many
organisms Used for structural purposes Breakdown of sugars supplies
energy for cell activities (cellular respiration)
Lipids
Made of CHO atoms Polymer = triglyceride: made of 3
fatty acid chains and 1 glycerol Examples: Fats, oils, waxes Types: Saturated and unsaturated
Long-term / stored energy Parts of biological membranes and
waterproof coverings Not soluble in water
Proteins
Macromolecules that contain CHON Monomer = amino acids
20 amino acids found in nature Each protein has a specific role
Reaction rates, cell processes, form bones and muscles, transport substances in and out of cells, fight disease
Nucleic Acids
Macromolecules that contain CHONP Monomer = nucleotide
Directions for making proteins & determining traits
Nucleotide Phosphate Sugar Nitrogen base
Generic (both DNA & RNA)
Phosphate Pentose sugar
Nitrogen base
DNA Phosphate Deoxyribose sugar
Nitrogen base (ATGC)
RNA Phosphate Ribose sugar Nitrogen base (AUGC)
Osmosis and Diffusion
Cell Membrane and Cell Wall regulate what enters and leaves cells
This occurs during two processes Osmosis Diffusion
Diffusion
Movement of dissolved molecules from one side of cell membrane to another
Particles move from an area where they are more concentrated to an area where they are less concentrated
Substances diffuse across a membrane without the cell using any energy
Osmosis Diffusion of water
across a selectively permeable membrane Most membranes
selectively permeable some substances
can pass through and others cannot
Water passes easily across most membranes
Cells
Cell: smallest unit of life Prokaryotic: no nucleus Eukaryotic:with a nucleus
Organelle: Specialized structure that performs important functions in the eukaryotic cell
Organelles
Cell Membrane Allows passage of oxygen, nutrients,
and wastes in and out of the cell Provides protection and support Found in plant and animal cells
Cell Wall Protects the plant cell, maintains its
shape, prevents excessive water intake Found only in plant cells
Organelles
Nucleus Contains all genes (genetic
information), chromatin, chromosomes and nucleolus
Controls protein synthesis Found in plant and animal cells
Chromosome Tightly coiled strands of DNA and
protein
Organelles
Chloroplast Site of photosynthesis, convert solar
energy to chemical energy Found only in plant cells
Mitochondria Site of cellular respiration (generates
energy) Convert chemical energy in food to a form
cells can use Found in plant and animal cells
Organelles
Cytoplasm Portion of the cell outside the nucleus Helps to maintain cellular shape Found in plant and animal cells
Ribosome Where proteins are made Found throughout the cytoplasm Found in plant and animal cells
Photosynthesis and Cell Respiration
What happens during photosynthesis? Plants (autotrophs) use energy from sunlight to
convert water and carbon dioxide into carbohydrates (energy) and oxygen
6CO2 + 6H2O (light) → C6H12O6 + 6O2
Reactants?Carbon dioxide (CO2) and Water (H2O)
Products?Glucose—Sugar (C6H12O6) and Oxygen (O2)
Photosynthesis and Cell Respiration
Cellular respiration… is the process that releases energy by breaking down food molecules (glucose) in the presence of oxygen; occurs in heterotrophs
6O2 + C6H12O6 6CO2 + 6 H2O + Energyoxygen+ glucose carbon dioxide + water+ energy
Compare this to the equation for photosynthesis….what do you notice?
Carbon Cycle
Essential molecule that makes up all organisms Proteins, fats,
carbohydrates Carbon is cycled…
Between the atmosphere, land, water and organisms
Short and long-term cycles
Carbon Cycle
In an ecosystem…1. Plants convert carbon dioxide into
carbohydrates (photosynthesis)2. Consumers eat producers, get carbon
from carbohydrates (glucose)3. Consumers release carbon to
atmosphere in carbon dioxide (breathing)
DNA
DNA is a double helix “twisted ladder”
Sides of ladder made ofsugar
(deoxyribose) phosphate
Rungs of ladder made of nitrogenous bases
Adenine, Thymine, Cytosine and
Guanine
DNA
Base-Pairing In a DNA molecule….
Adenine pairs with Thymine Cytosine pairs with Guanine
DNA is made of molecules called: Nucleotides
Sugar, phosphate and nitrogenous base (ATCG)
Protein Synthesis
Gene: coded DNA instructions that control the production of proteins within the cell Contain instructions for assembling
amino acids into proteins
Instructions for making proteins comes from DNA…must first be converted into RNA to leave the nucleus
DNA can’t leave the nucleus!
Protein Synthesis
Process that produces protein using instructions from DNA (gene) Uses RNA as an intermediate step
between DNA and proteins Two parts:
Transcription (nucleus) DNA mRNA
Translation (ribosome) mRNA protein (amino acid sequence)
Genetics
A gene is a section of DNA that forms a trait (protein).
For example: Hair color, Height, ear lobes….
Alleles are different forms of a gene.For example: brown hair, blond hair or
Tall and short.You get one allele for each trait from
your parents…
Cell Cycle
Cell cycle – The series of events that cells go through as they grow and divide. Has three main
parts: Interphase, Mitotic Phase, Cytokinesis
Cell Cycle (Mitosis)
Interphase: Cells increase in size and make new proteins and organelles. Chromosomes are replicated.
Mitosis: division of the nucleus. Divided into 4 phases (PMAT).
Cytokinesis: division of the cytoplasm.
**Produces IDENTICAL Cells**
Meiosis
Allows for genetic variation “Meiosis is the process in which the number of
chromosomes per cell is cut in half”
What are the differences between mitosis and meiosis? Mitosis produces two cells; cells are identical Meiosis produces four cells; cells are unique; occurs
only in sperm/egg cells
What are the similarities between mitosis and meiosis? First phase identical (meiosis phase 1); form of cell
division
Comparison
Mitosis Meiosis
Purpose Copy / make more cells
Make reproductive cells (gametes)
# of cell divisions 1 2
Ending # of cells 2 4
Resulting cells Genetically identical
Genetically different
# chromosomes in each ending cell
46 (diploid)
23 (haploid)
Comparison
Cells and Chromosomes
Diploid: 2 copies of each chromosome All cells except sperm and egg cells Mitosis
Haploid: one copy of each chromosome sperm and egg cells only Meiosis
Humans 46 chromosomes Reproductive cells have 23 chromosomes
Genetics
Dominant allele – the allele that “wins”. We use a capital letter “R”
Recessive allele – the allele that is hidden or loses . We use a lower case letter “r”.
RR = Dominant, Dominant - HomozygousThis person can roll their tongue
Rr = Dominant, recessive – Heterozygous (hybrid)
This person can roll their tongue
rr = recessive, recessive - Homozygous This person can’t roll their tongue
Genetics
Each organism must inherit a single copy of a gene (allele) from each of its parents Organisms have two copies of each
gene (genotype 2 letters)
Gametes (sperm and egg cells) each contain one copy of each gene
Evolution
Evolution – change over time It is the process by which modern organisms
have descended from ancient organisms. How well an organism is adapted to its
environment
Current scientific facts, observations and hypotheses all combine to create current evolutionary theory a well-supported, testable explanation of the
biological diversity on Earth.
1. Tortoises longer neck for sparse
vegetation. Shorter neck where vegetation was more abundant.
2. Finches Darwin noticed that
these birds have different shaped beaks, adapted to their food source (seeds)
Evidence for Evolution
Fossil Record – transitional fossils show us intermediate stages.
Example: horse and camel
Evolution by Natural Selection
Definitions:1. struggle for existence – members of a
species compete for resources2. Fitness – ability to survive and reproduce3. Adaptations – inherited characteristics
that increase an organisms chance of survival.
Variation
Caused by mutations (changes in DNA sequences Results in physical or behavioral changes May be beneficial or harmful
Increase or decrease survival rates
Inheriting different alleles from parents (causes individuals to look different) Results of meiosis are different every time Why we don’t look exactly like our siblings!
Population Ecology
Population – group of individuals of the same species that live in the same area.
Population Density = # individuals/area
Population Growth
Populations may stay constant or change drastically from year to year.
4 factors affect population size1. Natality – birth rate2. Mortality – death rate3. Immigration – movement of individuals IN4. Emigration – movement of individuals OUT
Limiting Factors
Limiting factors cause population growth to decrease. Density dependent – a factor that depends on
population size. Occurs when populations are large and dense.
Competition Predation Parasitism Disease
Density Independent: A factor that affects all populations in similar ways, regardless of population size.
Unusual weather Natural disaster Seasonal cycles Human activity
Exponential vs. Logistic Growth
Exponential growth – population grows at a constant rate…with unlimited resources this will occur.
Logistic Growth- occurs when growth slows or stops. -The largest number of individuals the environment can support is called the carrying capacity.
Carrying Capacity
Maximum number of individuals that an ecosystem can support
Limiting factors: Food availability Competition Disease Predation Natural Disasters
Biomes and Biodiversity
Biodiversity: the number of different species living in an ecosystem
Biomes: Rainforest, Tundra, Savanna
Sustainability
Sustainability: using natural resources at a rate that does not deplete them Condition in which human needs are met in
such a way that a human population can survive indefinitely
“The traditional definition of sustainability calls for policies and strategies that meet society’s present needs without compromising the ability of future
generations to meet their own needs.”(epa.gov)
Sustainability Issues in Washington
Invasive Species Non-native species causing ecosystem damage
Pollution (air and water)
Hydroelectric Dams
Overfishing
Forest Management
4 Components of Evolution
VISA = Variation Inheritance Selection (natural selection) A lot of time
Define & give examples of these four main components for evolution
Natural Selection Theory of Evolution Fit organisms
survive, reproduce, and pass on traits
Requirements: Variation Competition
Adaptations
Trait that increases survival
For Example, Beaks that make it
easier to eat insects Bright flowers to
attract pollinators Vascular tissue in
plants to adapt to life on land
Evidence for Evolution Fossil Record Biochemical
Similarities Shared anatomical
structures
Speciation
Evolution of a new species
Must be isolation between populations
Antibiotic and Pesticide Resistance
Populations will eventually become resistant to pesticides and antibiotics with overuse
Coevolution Two organisms evolve in response to
each other
Ex. Flowering plants and their pollinators
Source
http://learn.shorelineschools.org/shorewood/agiesy/documents/download/Biology+EOC+Review.ppt?id=247369.
Homeostasis
Homeostasis: Stable internal environment Internal body temperature Blood glucose level Blood pressure Hydration
Feedback Loops
Positive feedback: Increases the disturbance to a system. Body moves away from homeostasis Ex. Birth, stampede, clotting
Negative feedback: Reduces the disturbance to a system. Body tries to reestablish homeostasis Shivering, sweating, blood glucose