Unit 1 Test

3 things the check for when reading claims - evidence, source, mechanism

Why is science a reliable method to determining truths? - science is self corrective (peer review), conclusions will change based on new evidence, hypotheses is falsifiable, hypotheses are tested multiple times, experiments (blind, doubleblind, randomization)

Retracted - when a previously published paper is pulled because new information has shown that the paper has incorrect information in it

Data too clean - corrupted data (like getting heads exactly 50 times each heads when flipping a coin 100 times)

Benefits of binary choice research question - forces the methodology to be focused, forces the conclusion to be specific, influences the scientist to be unbiased

A hypothesis alone is usually to __ to test directly - broad

There can be _ predictions for one hypothesis - many

Prediction - what we expect to measure if the hypothesis is correct (the null is rejected)

3 Components of a good predictions - dosage, duration, measurement

Sample - subset of the population

x bar - symbol for sample mean

mu - symbol for population mean

With a larger sample size, sampling an outlier will have more/less of an impact - less

With a larger sample size, you are more/less likely to capture all the variation in the population - more

Standard deviation - how close the majority of the population sits to the mean

Why are we able to get away with a smaller sample size when there is evidence that the population has a narrow standard deviation? - Because there is little variability, so we don’t need a lot of measurements to capture it all

Why do we need a larger sample size when working with a population that appears to have a wide standard deviation? - Because there is a wider spread of data, so we need a lot of measurements to capture it all.

Standard error - An indication of how close the sample mean is to the population mean, Tells us something about how sample size relates to standard deviation, Ideally, we want standard error to be low

Statistically significant difference - Used to tell if the groups are truly different, and the results are not just due to chance. Scientists can use a variety of statistical tests to determine statistical significance. The conclusion of the test is often symbolized by the *

* - statistically significant less than a 1 in 20 chance of being wrong

** - statistically significant less than a 1 in 100 chance of being wrong

*** - statistically significant less than a 1 in 1000 chance of being wrong

Scientists credited with the theory of evolution - Charles Darwin and Alfred Russel Wallace

Theory of evolution - Species are related by common ancestry, they were not designed as separate entities. The characteristics of species can be \n modified from generation to generation.

Natural selection - the process by which species change over time

Natural selection occurs when - Individuals within a population vary in characteristics that are heritable. In a particular environment, certain versions of these heritable characteristics help individuals survive and reproduce more often than others.

Where does the variation come from? - Mutation!

Mutations - random mistakes in DNA replication

Scientific Theory - When a hypothesis that provides a framework which explains a widespread phenomenon has been tested many times, and in all those times the null hypothesis was rejected. That hypothesis becomes a Scientific Theory.

4 of many scientific theories in biology - The germ theory of disease, The cell theory, The chromosome theory of inheritance, The theory of evolution

4 things inside of atom - electron, nucleus, proton, neutron

Electrons move around the nucleus in - orbitals

Orbitals are grouped into levels called - electron shells

The electrons of an atom fill the _ shells first, before filling _ shells - The electrons of an atom fill the innermost shells first, before filling outer shells

The outer shell is the - valence shell

Electrons in the valence shell are - valence electrons

An atom is most stable, meaning not reactive with other atoms, when - its valence shell is filled

Covalent bond - when two atoms share valence electrons so that each atom can be more stable (as a molecule)

Non polar - Equal sharing of valence electrons between atoms in a covalent bond

Polar - Unequal sharing of valence electrons between atoms in a covalent bond

Lipids - consist of C H bonds

Carbohydrates - consist of C double bond O groups bonded to OH groups with some C H bonds \n Nucleic acids - consist of nucleotides

Phosphate group - sugar, nitrogenous base \n In general, lipids are - nonpolar

phospholipids - lipids that make up the cell membrane, are a polar

water phospholipids form - lipid bilayers

Cell membrane is - lipid bilayer. The membrane separates inside vs outside of the cell and only lets certain substances through

Saturated lipid - hydrocarbon chains consist of only single bonds between the carbons

Unsaturated lipid - hydrocarbon chains have one or more double bonds (are kinked) \n Decreased temperature lipid movement in the membrane, causing hydrophobic tails in the center to together - Decreased temperature slows lipid movement in the membrane, causing hydrophobic tails in the center to pack closer together.

Simple diffusion - diffuse directly through the cell membrane down their concentration gradient

Facilitated diffusion - uses a protein channel to diffuse through the cell membrane down their concentration gradient, does not require energy

Active transport - move through the cell membrane against their concentration gradient through a protein channel and uses energy

Primary active transport - protein pump moves ions against their concentration gradient. ATP is used

Secondary active transport - cotransporter transport protein uses the energy released by a solute moving down it concentration and chemical qradient to power other solutes moving against their gradients