Unit 1 Test

3 things the check for when reading claims

evidence, source, mechanism

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

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

*

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

Natural selection

the process by which species change over time

Natural selection occurs when

Individuals within a population vary in characteristics that are heritable

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

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

Nucleic acids

consist of nucleotides

Phosphate group

sugar, nitrogenous base

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

Saturated lipid

hydrocarbon chains consist of only single bonds between the carbons

Unsaturated lipid

hydrocarbon chains have one or more double bonds (are kinked)

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

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