What is science, what are the 3 key features?
Observe the world, make sense of the observations, predict the future
What two assumptions does science make?
- The universe is governed by the laws of nature
2. With the right technology we can observe the world and make inferences about these laws of nature
Explain the scientific method
A non linear method that follows the pattern of observing, hypothesising and predicting.
Difference between scientific law and theory
Law is a mathematical construct
Theory is an explanation of a phenomenon
Explain the importance of models in science
Help us test the hypothesis for systems which are intangible, i.e. in astronomy things are too far to observe directly
What is an experiment?
A scientific procedure undertaken to make a discovery, test a hypothesis, or demonstrate a known fact.
Explain what is meant by scientific revolution/paradigm shift
When a new theory is discovered which renders irrelevant or incorrect the previously held beliefs
List some of the current issues with the practice of science:
- Publication Bias: The tendency for academic journals to only publish papers which prove what they set out to prove, not papers where the hypothesis was incorrect, or they disproved something, even though this may be equally valid.
- Selective Reporting - The tendency for scientists to leave out negative portions of their experiment in their reporting. For example if the test supported their hypothesis half the time, and didn’t the other half, they may leave out the results where it didn’t work and leave in the results where it did.
- Publish or Perish - The tendency for scientific backers or institutions to place a large emphasis on getting published. This places pressure on scientists to quickly get results, often at the expense of quality scientific work. This can be worsened by publication bias, and may lead to selective reporting.
Distinguish betwen the natural and social sciences
- Natural sciences is about the world and how it functions
- Social sciences is about humanity, and how we function
Define and identify nonscience
Anything that doesn’t engage in the scientific method
Define and identify pseudoscience
-Intentional or non-intentional use of scientific language which is ultimately misleading.
Describe the English & Metric measurement systems
- Metric is the universal system of measurements, which allow you to easily swap between measurements (powers of ten), and each of the measurements have only one base unit
- Only 3 countries use the English measurement system (US among them)
Distinguish between Random & Systematic error
- Any data always has random error, alters the precision of your data
- Systematic error can be reduced or even eliminated, alters the accuracy of your data
List the taxonomy of data
Nominal, Ordinal, Discrete, Continuous
- Nominal - Data which is called by name (i.e. the names of fruits, Apples Oranges etc.)
- Ordinal - Data which is ranked (i.e. the placement in a race, 1st, 2nd etc.)
- Discrete - Data which is an integer (1, 5, -7, 9, 12 etc)
- Continuous - Data which is a real number (2.3, 8.65, -9.75)
Logarithmic Scales
When there is a lare range of data we graph using logarithmic scales
List The common ways data can be presented graphically
- Pie Graphs (Nominal data)
- Bar Graphs (Ordinal and Discrete data)
- Line Graphs (Continuous data)
Astronomy:
Explain the theory of Wave-Patricle Duality
-Well supported experiments suggest that light acts as both a wave and a particle in different circumstances. (double-slit experiment, and photoelectric effect)
Explain the scope and importance of the EM spectrum
- Classification from the highest to lowest forms of energy
- Important to measure all these forms of energy so we can understand what the universe is made of
Explain the importance of light in astronomical observations:
- Proxies, because things are hard to measure in space we use proxies (light) in order to measure certain things about space:
- Temperature - Black body thermal radiation spectrum. Wayne’s Law
- Distance - a) Mirrors and lasers; b) parallax; c) Standard candle (inverse square law); d) redshift
- Speed and Direction - Blueshift when the object is moving towards you; redshift when it is moving away
Concept of Look-back time
The time it takes for light to reach you
Explain the Scientific Process Involved in the Development of the Big Bang Theory
- The universe began with a big bang event which is the origin of the universe, and the universe is expanding
- Because everything is moving away from each other we suspect that there was an explosion that everything is moving away from
Models of the Big Bang
Balloon Model
Evidence for Big Bang Theory
Redshift of galaxies
Limitations of the balloon model, strengths of the balloon model
It’s a two-dimensional solution for a 3-dimensional problem, however it is easy to visualize the concept, and quick to reproduce.
Explain how we know we are not at the center of the Universe
Everything is moving away from everything else
Implications of Hubble’s Law
Hubble's law is a statement of a direct correlation between the distance to a galaxy and its recessional velocity as determined by the red shift. v = Hd Where: v = recessional velocity H = Hubble's Constant d = distance
Why does the greenhouse effect in the atmosphere occur?
CO2, water vapor, and other gases absorb infrared radiation of Earth
Earth’s global climate depends on:
Green-house gasses, albedo and energy from the sun
Quantitative measure for global temperature during the last 400000 years has been determined from:
Oxygen isotopes present in air bubbles trapped in ice cores (O-16,O-18)
The key factor the causes the presence of seasons on Earth is
The tilt of the Earth
Which of the following is not considered a fossil fuel? Coal Petroleum Natural Gas Biodiesel
Biodiesel
The controversy about Global Warming concerns:
Whether global warming is due to natural or anthropocentric forgings
What causes changes in temperature?
Variations in Earth’s orbit and hence periods of ice ages alternate with warm period.
What best summarizes the information flow within a cell?
DNA => RNA => protein
If a woman is a carrier for a color-blind recessive allele and her husband is normal, what are the chances that their son will be color-blind?
None, since the father is healthy
Evolution can be defined as
Change in frequency of genetically determined characteristics (traits) within a population over time
Which of the following crosses would always result in offspring that only display the dominant phenotypes? TT x tt Tt x Tt TT x TT Tt x Tt
Both TT x tt and TT x TT
What is the best way to determine the relatedness of two organisms fossils?
Skeletal anatomy, and DNA similarity
Nuclear plants operate based on
Nuclear fission mechanism
T/F: Frequency of recessive genes is lower than the frequency of the dominant genes in a population’s genotype
False
T/F: Frequency of recessive genes is lower than the frequency of the dominant genes in a population’s phenotype
True
What is the purpose of the scientific notation?
To represent very large or very small numbers, and to make mathematical manipulation easier
A supported scientific explanation which could be rejected upon future experimentation is a
Theory
Which of the following are scientific laws?
Amax = b/T
Expansion of the Universe since the Big Bang event
Force due to gravity is F = mg
Amax = b/T
Force due to gravity is F = mg
The big bang refers to
The initial birth moment of the entire universe in a tremendous explosion
Hubble’s Law Constant provides the following information about the observable universe
It is 13.6 billion years old
The longest wavelength portion of the electromagnetic spectrum is known as
Radio waves
How can one test the wave like behavior of light?
Set up a double slit experiment
Lines associated with the atomic spectra represent
Energy absorbed as electrons move from one atomic orbital to another
Scientist prefer to use the Metric System because
It only has one unit for each base property
What effect energy coming from the sun?
Only nature
How often does earth’s orbit change
Once every 100000 years
What do sunspots do and how often do they occur?
Every 10-11 year,s they make the sun more radiant
What happens to the climate of the earth with increased volcanic activity?
Higher albedo, lower temperature
Who influences greenhouse gasses?
Mainly human interference
Why are we concerned with CO2?
CO2 absorbs highest energy in earth’s radiation and atmosphere is not saturated by CO2
EPA
Environmental protection agency
IPCC
Intergovernmental Panel on climate change
WHat are the types of energy?
Mechanical Electrical Chemical Nuclear Radiant
What forms of energy do we use most often today?
Fossil fuels (chemical), nuclear, hydropower (mechanical)
What forms of energy do we expect to use more in the future?
Solar (radiant), geothermal, and hydrogen-based energy
Problems with the energy we use today
Fossil fuels: Nonrenewable and burning them emits CO2
Nuclear: Produces nuclear waste
What are chromosomes?
Macro-molecular arrangements of DNA
What are genes:
Segment/stretch of DNA used to determine which protein to produce, and when or where
What is a genomes?(Genotype)
Sum of all the genes in the organism
Genotype vs Phenotype
Genotype is the genes in the organism, phenotype is the gene that is expressed
What was the Hershey-Chase experiment concerned with
Evidence that DNA is the genetic material. Proven based on the atomic difference, DNA has phosphorous not sulfur, and proteins have sulfur, not phosphorous.
When does replication take place?
During mitosis, where mutations can take place
What are Mendel’s laws of herdity?
Law of Dominance
Law of Segregation
Law of Independence
What is silent mutation, and codon-code redundancy?
There is a built in redundancy in the codon-code, there are 64 codes to make 20 amino acids, this allows for silent mutations, where a mutation takes place on a DNA level, but not a protein level.
What are the mechanisms for introducing genetic novelty?
Semiconservative replication and reproduction
What are alleles?
Alternative versions of a gene for the same trait/characteristic (green/brown eyes, red/blonde hair etc.)
What is heterozygous and homozygous?
Heterozygous: Parents give different alleles for a train
Homozygous: Parents give same alleles for a trait
How do we use DNA to our advantage?
Prediagnostic testing for diseases
Genetically modified organisms (used in agriculture and pharmaceutical)
DNA fingerprinting (used in forensics/legal matters)
Natural selection
Chooses the best possible pool of genes based on the ability to survive long enough to reproduce
Evidence for evolution:
Skeletal similarity, DNA similarity, embryonic development, neuronal development
Graphical representation of evolution
Phylogenetic trees
Success of humanity as a species
Only organism that occupies all continents, based on our ability for mental capacity.
We evolved out of Africa
What is an atom?
Smallest building block of matter
What is the size of an atom called?
Angstrom
What is a chemical element
Pure form of matter made of one kind of atom
How do we form chemical elements?
Nuclear fusion reaction (sun or nuclear)
What is penicilin?
An antibiotic
What is chirality?
The handedness on a molecular level, measured by determining the rotation of the molecules.