Biology EOC Review Session

Biology EOC

Test is the second week back in January!You will be taking the test during your regularly scheduled science class

5-6 scenarios 40 questions total

40-45% Cells, Genetics, DNA 30-35% Populations and Ecology 25-30% Evolution

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

I predict…reason

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…

Macromolecules

“Giant Molecules” (polymers)Linked together with smaller subunits (monomers) Carbohydrates Proteins Fats (lipids)

Carbohydrates

Compounds made of carbon, hydrogen and oxygen

Used as a main source of energy for many organisms

Used for structural purposes Breakdown of sugars supplies

energy for cell activities

Proteins

Macromolecules that contain nitrogen, carbon, hydrogen and oxygen

Composed of smaller molecules called 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

Fats (lipids)

Compounds made of carbon, oxygen and hydrogen atoms Glycerol + Fatty acid = Lipid Fats, oils, waxes Saturated and unsaturated

Not soluble in water Used to store energy Parts of biological membranes and

waterproof coverings

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

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.

Cytokinesis: division of the cytoplasm.

**Produces IDENTICAL Cells**

DNA

DNA is a double helix DNA is a double helix ““twisted laddertwisted ladder””

Sides of ladder made ofSides of ladder made ofsugar sugar

(deoxyribose) (deoxyribose) phosphatephosphate

Rungs of ladder made of Rungs of ladder made of nitrogenous basesnitrogenous bases

Adenine, Thymine, Adenine, Thymine, Cytosine and Cytosine and

GuanineGuanine

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…

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

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

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

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!

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)

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.

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

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

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