Biology 1 (Unit 1)

Science

aims to understand the natural world through observation, reasoning, and testing

\-Seeks out Facts

Inductive

Uses observation develop general conclusion, collecting lot of data and finding a pattern

Deductive

Start broad and work down to a specific conclusion, whittling things out, test in a way to try to eliminate possible explanation, trying to find the specific cause

What are the two reasonings Science use?

Inductive and deductive

Science is defined by

the scientific method

Steps of the Scientific method

observation, hypothesis, test the hypothesis (experiment), analyze results using statics, derive a conclusion

Scientific Method

A systematic approach scientist take to understand the natural world

hypothesis

a tentative explanation based on observation

Experiment

manipulating variables in controlled environment to deduce cause

conclusion

prepare the results to share with others

How conduct a study and experiments?

good studies are hypothesis driven, repeatable, start with a good hypothesis (measurable, testable, falsifiable), design the experiment (experimental/ control group), test hypo. with variables, dependent variable, independent variable

experimental group

a group that experience the manipulation of variables

control group

a group that is not manipulated

variable

a factor that influences a process (something we can measure)

Dependent Variable

a factor that can be measured (AKA a response Variable)

Independent Variable

factors that vary (AKA Explanatory variable)

Controlled variable

A variable you want to pay attention to, but something your trying to keep constant

Is Science only about performing studies and experiments?

Classification of all life on earth, human genome sequencing

Theory

an explanation that has undergone rigorous testing is not yet falsified

are theories set in stone?

no

does a single experiment prove anything?

Never use the word prove, when you talking about a hypothesis unless it is to prove something it is wrong

Research Biology

Driven to understand life to the fullest extent possible

Applied Biology

uses results of pure research for the benefit of humans

What are some Characteristics of Science?

Works with the physical realm, measurable, works off falsifiable hypothesis, we have to be able to repeat our test

Evolutionary Biology

seeks to understand formation and maintenance of biological diversity

Evolution

Change in the frequency of alleles from one generation to the next

alleles

one of two or more versions of a gene

Charles Darwin

1859-published book

famous for natural selection

Darwin’s Natural Selection: (his observation)

variation exist in nature and is heritable, observation of offspring, offspring must compete for limited resources , Differential survival and reproduction

Came to the conclusion: that your ability to pass genes on to future generations depends on your ability to survive and reproduce

Alfred Russel Wallace

Didn’t publish until after Darwin, independently came to the same ideas

Where do we use evolution?

Medicine, agriculture, invasive exotics (species), conversation of biodiversity

Does evolution have anything to do with the origin of life?

Bill Martin

Chemistry

study of composition, structure and properties of matter and the changes that matter undergo

matter

has mass and occupies space, solid, liquid, gas

Protons

positively charged particles

neutrons

neutral particles

electrons

negatively charged particles, surround the nucleus, determine chemical nature, neutral atoms have same number of electrons and protons

Elements

are pure substances that contain only one type of atom

Atoms

We can describe elements based on characteristics , Atomic number= number of protons, mass number = # protons +neutrons

Isotopes

atoms of a single element that differ by the number of neutrons

atomic weight/ atomic mass

is the weight average of the atomic mass of an element’s different isotopes

radioactivity

breakdown from higher to lower numbers of neutrons

orbitals

the are where an electron is found, no orbital can contain more than two electrons

energy shell

a discrete level of energy an electron possess (quanta), energy of an electron related to distance from nucleus

potential energy

energy due to the position of an object, absorbed

Valence electrons

electrons in the outer shell, determines behavior

Molecules

a group of atoms held together in a stable association by chemical bonds

chemical bonds

an attractive force links two atoms

Covalent Bonds

two atoms share electrons in their outer shell attain stability, strong bond type, more bond=stronger

chemical bonds

unequal sharing of electrons can happen, electronegatively, polar molecules, nonpolar

ionic bonds

formed by attraction between ions of the opposite charge, ions are charged atoms, electrons are transferred, weaker bon than covalent

cation

more protons than electrons=net positive charge

anion

fewer protons than electrons= net negative charge

hydrogen bonds

sharing of a hydrogen atom between two electronegative molecules, weaker bond but strength is in numbers

Van der Waals Forces

attraction between atoms due to random variation in the electrons distribution in a molecule, weakest “bond”

Chemical reaction

occurs with the formation and breaking of bonds, they either release or absorb energy

energy

the capacity to do work, breaking bonds require this

Chemical reactions can be

reversible

temperature

heat is energy

catalyst

things to add to chemical reaction to speed up the reaction time example: enzymes

oxidations

reduced reaction involve transfer of electrons, oxidized=loose, reduced=gain

Acids

substances that dissolve in water and release H+ when in solution, Strong__ release more hydrogen ions

Base

accepts H+ ions when dissolved in water to lower the H+, Strong ___ can very effectively pull H+ off of other molecules

pH scale

a way to express the hydrogen ion concentration

Buffers

a substance that resist the change in pH and is made from the combination of weak acids and responding base, bicarbonate buffer system

Water

exist in 3 states like other matter, covers 71% of the world, required for all life

Chemical Structure

polar covalent bonds, from hydrogen bonds, tetrahedron shape

Solution

is produced water a subs dissolves water

solute

the substance being dissolved

solvent

what is doing the dissolving

Molarity

refers to moles per liters of solution

mole

the weight of a substance in grams that corresponds to the molecular weight of a substance 6.02X10^23

hydrophilic

if a polar molecule interacted with water

hydrophobic

when the non polar molecules do not dissolve with water and aggregate together

Solid Water

water is less dense than liquid

thermal capabilities

water has high specific heat (Capacity)

Specific heat

amount of heat required to raise temperature 1g of substance by 1 degree C

Heat Vaporization

amount of energy required to change 1 g of a sub from a liquid to gas

Water is (1)

dynamic (ever changing)

Surface tension

allows it to resist an external force

water is (2)

adhesive, attracts to other polar molecules, capillary action