SEMESTER EXAM

STUDY GUIDE

Chapters

1 – Scientific Method and Characteristics of Life

6 – Atomic Structure and Macromolecules

7 – Microscopes and Cell Parts

9 – Cell Cycle and Mitosis

10 – Meiosis and Genetics

14 – History of Life

15 – Theory of Evolution

Objective, Hypothesis, Experiment, Data, Conclusion

Objective – question or puzzle brought on from observations

Hypothesis – testable explanation of a situation

Experiment – test hypothesisData – qualitative or quantitative data

recorded in experimentConclusion – explanation of results that

show either proof or dis-proof of hypothesis

SCIENTIFIC METHOD

Independent variable – factor that is being manipulated and tested in an experiment

Dependent variable – factor that is being measured that depends on changes to the independent variable

Constant – remains fixed, does not change

Control – any variable that you control in experiment (you may control the constants)

Experimental group – group exposed to the factor being tested

Control group – group used for comparison

EXPERIMENT

Theory – explanation of a natural phenomenon supported by many observations and experiments

Law – describes relationships under certain conditions

Ethics – set of moral values or principles that guide decisions in society

SCIENCE

Made of one or more cell – organism unicellular and multicellular

Grows and develops – caterpillar changes to butterfly

Adaptation – bird species develop different beaks over time

Reproduces – pass traits to next generation

Responds to stimuli – dog salivates to smell of food

Requires energy – eating or photosynthesis

Maintains homeostasis – internal stability, sweating or shivering

Displays organization – atoms, molecule, cells, organism

CHARACTERISTICS OF LIFE

Atom – building blocks of matter

Protons – positive, inside nucleus, equal to electrons

Neutrons – neutral, inside nucleus

ATOMIC STRUCTURE

Electrons – negative, orbit outside nucleus, equal to protons, very small in mass

Atomic number – number of protons in an atom

Atomic mass – weight of protons and neutrons

Covalent bond – chemical bond formed when electrons are shared

Ionic bond – electrical attraction between two oppositely charged atoms (ions)

Macromolecule Made of Function or Example

CarbohydrateMonosaccharaide

DisaccharidePolysaccharide

Provides support for plants (cellulose)

Energy (sugar, bread)

Lipid Carbon and HydrogenFatty acids Fats, oils, waxes

Protein Amino Acids Aids in digestion (enzymes)

Nucleic Acid NucleotidesA, T, C, G (U) DNA and RNA

MACROMOLECULE

Compound Microscope – uses series of lenses and light

Dissecting Microscope – low magnification observation

Scanning Electron Microscope – directs electrons over surface to produce 3D images

Transmission Electron Microscope – electrons passed through specimen to fluorescent screen

MICROSCOPES

All living organisms are composed of one or more cells

Cells are the basic unit of structure and organization of all organisms

All cells come from preexisting cells

CELL THEORY

A – Body Tube – holds ocular lens certain distance from objective lens

B – Nosepiece – rotates objectivesC – Objective lens – scanning, low, high powers, magnify

imageD – Stage Clips – holds the slide on the stageE – Diaphragm – controls amount of light that passes

through the specimenF – Light source – provides lightG – Ocular lens – eyepiece, magnifies lightH – Arm – carry microscope by arm and baseI – Stage – platform where the slide with specimen is

placedJ – Course knob – large adjustmentsK – Fine knob – small adjustmentsL – Base - support, carry by arm and base

MICROSCOPE PARTS

Prokaryotic cell – do not have a nucleus or membrane bound organelles (bacteria)

Eukaryotic cell – contain a nucleus and membrane bound organelles (plant and animal)

TYPE OF CELLS

Nucleus – contains DNA, control center

Nuclear envelope – membrane surrounds nucleus, contains pores

Nucleolus – center of nucleus, site of ribosome production

CELL PARTS

Plasma membrane – flexible phospholipid bilayer covers cell surface, selectively permeable (lets some molecules pass though while keeps others out)

Cell wall – rigid structure surrounds plant and bacteria cells, provides support

CELL PARTS

Mitochondria – powerhouse, converts food into energy

Endoplasmic Reticulum (ER) – folded membrane, rough contains ribosomes

Central Vacuole – large in plant cell, stores water, food and waste

CELL PARTS

Vesicle – storage and transport food and waste

Lysosomes – type of vesicle that contains digestive enzymes to breakdown food

Chloroplasts – in plant cells, photosynthesis occurs

Golgi apparatus – fedex, package, ships and stores protein

CELL PARTS

Cytoskeleton – microtubules and microfilaments framework

Ribosomes – protein synthesis

Cytoplasm – semifluid material inside cell

Cilia / flagella – hair like and tail like structures for movement

CELL PARTS

Plant Cell Animal Cell

Cell Wall CentriolesChloroplast Cilia / flagellaLarge Central Vacuole Lysosome

PLANT CELL VS ANIMAL CELL

Interphase – (G1, S, G2) cell spends most of its time

Mitosis – cell’s nucleus and nuclear material dividesCytokinesis – cell’s cytoplasm divides and cell

splits into two

CELL CYCLE – cells reproduce by a cycle of growing and dividing

InterphaseG1 - growingS – DNA duplicatesG2 – prepare to

divide

Meiosis – reduction of chromosome with two cell divisions, make gametes

Centriole – microtuble bundle

Centromere – center of chromosome where sister chromatids are attached

Chromosome – tightened and condensed form of DNA

Chromatin – relaxed state of DNA

Chromatid – (sister) identical sides of replicated chromosme

Cell plate – structure that forms in a plant cell during cytokinesis

Gene – segment of DNA that codes for proteins

Gamete – sex cells, have half the number of chromosomes, egg and sperm

Spindle apparatus – microtuble structure that moves chromosomes

Homologous chromosomes – same length, from different parents, same centromere position, carry genes that control same trait

Crossing over – during prophase 1 in meiosis, exchange genetic info on homologous chromosomes

Law of segregation – two alleles for each trait separate during meiosis then unite in fertilization

Law of independent assortment – random distribution of alleles occurs during gamete formation

Prophase – nuclear membrane and nucleolus disappear, spindles form, chromosomes condense

Metaphase – chromosomes line up in the middle

Anaphase – sister chromatids pull apart

Telophase – two nuclei, nuclear material reappears, spindles disappear

MITOSIS

Prophase I – homologous chromosomes condense and pair up, crossover

Metaphase I – homologous chromosomes line up in middle

Anaphase I – homologous chromosomes pull apartTelophase I – two nuclei (cytokinesis follows) – end

with 2 cells haploid number of chromosomes

Prophase II – chromosomes condenseMetaphase II – chromosomes line up in middleAnaphase II – sister chromatids pull apartTelophase II – two nuclei in each cell, cytokinesis

follows ending with 4 haploid cells

MEIOSIS

MitosisAsexual reproductionTwo identical daughter cells are created

MeiosisSexual reproductionResults in genetic variation, 4 unique cells

Crossing over occurs

MITOSIS VS MEIOSIS

Haploid – n number of chromosomes, gametes

Diploid – 2n number of chromosomes, body cells

Alleles – alternative form of a single gene passed from generation to generation

Heterozygous – two different alleles for a trait (Rr)

Homozygous – two same alleles for a trait (RR or rr)

Hybrid – heterozygous (different)

Purebred – homozygous (same)

GENETICS

Phenotype – physical appearance (yellow, round, straight)

Genotype – organisms allele pairs, represented by letters ( YY, Rr, cc, Tt)

Dominant – will mask recessive trait (genotype has capital letter RR or Rr)

Recessive – trait that is masked by dominant trait (genotype only lower case rr)

GENETICS

Blue body yy

Stubby nose ll

Round eyes RR, Rr

Oval eyes rr

Squarepants SS, Ss

TELL GENOTYPE

Long nose LL, Ll

Hybrid yellow Yy

Heterozygous round eyes Rr

Purebred blue yy

TELL PHENOTYPE

LL long nose

Yy yellow body

Rr round eye

rr oval eye

SS squarepants

Ss squarepants

Wilma Rr Wilbur RR

Kids possible genotypes RR, RrKids possible phenotypes round eyes

Round eyes 100%Oval eyes 0%

GENETICS PROBLEMS

RR RR

Rr Rr

R RR

r

Susie - blue yy Bob - heterozygous yellow Yy

Kids possible genotypes Yy, yyKids possible phenotypes yellow, blue

Blue body 50%

GENETICS PROBLEMS

Yy yy

Yy yy

Y yy

y

Precambrian – Autotropic prokaryotes enrich the atmosphere with oxygen

Paleozoic Era – Cambrian explosion

Mesozoic Era – first mammals appear, contains 3 periods – Triassic, jurassic, Cretacous

Cenozoic Era – primates evolve and diversify, time period you live in

EVENTS IN PROPER ERA

Plate tectonics – movement of several large plates on Earth’s surface

Paleontologist – scientist studies fossils

K-T Boundary – layer high levels iridium, evidence meteorite wipe out dinosaurs

Precambrian – autotrophic prokaryotes enrich atmosphere with oxygen

HISTORY OF EARTH

Radiometric dating – use decay of radioactive isotopes to measure age of rocks

Relative dating – method determine age of rocks by comparing with those in other layers

Half-life – half time for isotopes to decay

Fossil – preserved evidence of organisms, show species changed over time, formed in sedimentary rock

HISTORY OF LIFE

Spontaneous generation – old idea that life arises from nonlife

Theory of biogenesis – living organisms can produce other living organisms

Endosymbiont theory – prokaryotic cells were involved in formation of eukaryotic cells

Primordial soup hypothesis – energy from sunlight and lighting allow first organic molecules to form

Early atmosphere missing element of Oxygen

HISTORY OF LIFE

Natural selection – struggle to survive those better equipped will survive and reproduce

Adaptation – trait shaped over time by natural selection to increase survival or reproductive success

Artificial selection – human selective breeding desirable traits, domesticated animals, modern crops and dog breeds

EVOLUTION – cumulative changes in the groups of organisms through

time

Fitness – measure of number of viable offspring organism produces, increase # offspring increase fitness

Ancestral trait – more primitive traits shared by species with common ancestor (bird ancestor - teeth and tail)

Derived trait – newly evolved traits (feathers)

Homologous structure – anatomically similar structures inherited from common ancestor (forelimbs of vertebrates)

Vestigial structure – body structure no longer used for original function reduced in size (whale pelvic bone)

Analogous structure – same function but different structures (bird wings and butterfly wings)

STRUCTURES

Mimicry – one species evolves to resemble another species (king snake)

Camouflage – allows organisms to become almost invisible to predators (leaf bug)

Sexual dimorphism – different phenotypic appearance between males and females like coloration, size, ornamentation or behavior (peacocks)

ADAPTATIONS

Humans have NOT always been dominant species on earth

Biology – study of life

Bacteria – first living organism on Earth

EXTRA