life science

Life Science

Search “book biology quick review”

Classifying the Diversity of Life• There are three domains of living things:

Cell Theory

• the cell is the smallest unit of life; all cells arise from pre-existing cells

Idealized Animal Cell

Idealized Plant Cell

Reproduction and Heredity

Some Terminology• Same alleles = homozygous• Different alleles = heterozygous

Homologous Chromosome Pair

Sister Chromatids

Dominant and Recessive• In the heterozygous condition, one allele gets

expressed and the other one doesn’t.

• The allele that is expressed is said to be dominant.

• The one that is not expressed is recessive.

Homozygous and Heterozygous• Homozygous dominant = AA

= dominant trait expressed

• Heterozygous = Aa= dominant trait expressed

• Homozygous recessive = aa= recessive trait expressed

Genotype and Phenotype• Genotype is the set of alleles an individual has for a

character.

• Phenotype is the trait that is expressed.

• Brown eyes is dominant to blue in humans. A man with brown eyes (whose father had blue eyes) marries a woman with blue eyes. Predict the genotype and phenotype frequencies of their offspring.

Acquired vs Inherited Traits• Inherited – passed via DNA in sperm/egg from

parents; e.g. eye color

• Acquired – not inherited; e.g. a learned behavior; strengthening muscles; tattoo

Evolution

When the monster came, Lola, like the

peppered moth, remained motionless

and undetected. Harold, of course was

immediately devoured.

• Morphological adaptation – physical features

• Physiological adaptation – chemical reactions

• Behavioral adaptation - behaviors

Genetic VariationOverproduction of OffspringDifferential ReproductionChange in frequency of traits

• Evolution accounts for both the unity (things in common) and diversity (lots of different types) of life

Organisms and Their Environment

Behavior• Learned vs innate behaviors (instinct)

Energy flow and chemical cycling

Physical Science

Atomic Structure

• Matter is anything made of atoms

• States: solid, liquid, gas

• Matter cannot be created or destroyed

• Chemical reaction: Bonds broken, atoms rearranged

Chemical Reactions• Chemical reactions - the breaking and making

of bonds; atoms are rearranged (not created, destroyed, or changed into different elements)

Work

• Work = force x distance

• Energy is the “capacity to do work”

Heat vs Temperature• Heat is the total energy of molecular motion in a

substance while temperature is a measure of the average energy of molecular motion in a substance.

• Heat energy depends on the speed of the particles, the number of particles (the size or mass), and the type of particles in an object.

• Temperature does not depend on the size or type of object. For example, the temperature of a small cup of water might be the same as the temperature of a large tub of water, but the tub of water has more heat because it has more water and thus more total thermal energy.

• Convection – movement of warmed matter

• Conduction – transfer of energy from particle to particle

• Radiation – electromagnetic waves transport energy through space

velocity acceleration

Acceleration requires force to be applied

Others

• Momentum = mass x velocity

• Work = force x distance

• Gravitation force = mass x gravity

Newton

• Newton 1 – body remains at rest or motion unless acted on by force

• Newton 2 – Force = mass x acceleration; objects with greater mass require more force to move them

• Newton 3 – every action is countered by an equal and opposite reaction

Simple machine changes the direction or magnitude of force

• Electric current is a flow of electric charge through a medium. This flowing electric charge is typically carried by moving electrons in a conductor such as wire.

magnetic fields are produced by the motion of electrical charges

A circuit is an unbroken loop of conductive material that allows electrons to flow through continuously without beginning or end.If a circuit is "broken," that means its conductive elements no longer form a complete path, and continuous electron flow cannot occur in it.

Diff wavelength (frequency), different “color” – different amplitude, different intensity

Doppler effect – change in frequency of a wave for someone moving relative to the source of the wave – higher pitch as move toward, lower pitch as move away

Diff wavelength (frequency), different “color” – different amplitude, different intensity

THE SCIENTIFIC METHOD

STEP 1Make

observations.

STEP 2Formulate ahypothesis.

STEP 3Devise

a testableprediction.

STEP 4Conducta critical

experiment.

STEP 5Draw

conclusionsand makerevisions.

The scientific method rarely proceeds in a straight line. Conclusions, for example, often lead to new observations and refined hypotheses.

Controlled Experiment• Control – compare groups with only one

difference – the variable you are interested in testing (manipulating) – all other variables are held constant (controlled)

• Replication – multiple subjects in each test group

Analysis and Communication• Statistics

• Date in graphs and tables

• Present results to colleagues and the public

Safety• Goggles and other safety equipment• Disposal and clean up of spills• No eating or drinking in science lab• Etc…• Proper use and care of living organisms

Metric System• Mass – gram• Volume – liter• Length – meter

• Milli – 1000th

• Centi – 100th

• Kilo - 1000

People• Newton – laws of motion; gravity• Mendel – genetics• Pasteur – airborne disease• Darwin – evolution• Einstein – relativity• Bernoulli – energy in fluids and air