Chapters
1 – Scientific Method
and Characteristics
of Life
SEMESTER EXAM
STUDY GUIDE
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
SCIENTIFIC METHOD
 Objective, Hypothesis, Experiment, Data, Conclusion
Objective – question or puzzle brought on from
observations
Hypothesis – testable explanation of a situation
Experiment – test hypothesis
Data – qualitative or quantitative data recorded
in experiment
Conclusion – explanation of results that show
either proof or dis-proof of hypothesis
EXPERIMENT
 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
SCIENCE
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
CHARACTERISTICS OF LIFE
 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
ATOMIC STRUCTURE
Atom – building blocks of
matter
Protons – positive, inside
nucleus, equal to electrons
Neutrons – neutral, inside
nucleus
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
Macromolecule
Made of
Function or Example
Carbohydrate
Monosaccharaide
Disaccharide
Polysaccharide
Provides support for plants
(cellulose)
Energy (sugar, bread)
Lipid
Carbon and Hydrogen
Fatty acids
Fats, oils, waxes
Protein
Amino Acids
Aids in digestion (enzymes)
Nucleic Acid
Nucleotides
A, T, C, G (U)
DNA and RNA
MICROSCOPES
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
CELL THEORY
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
MICROSCOPE PARTS
A – Body Tube – holds ocular lens certain distance from objective
lens
B – Nosepiece – rotates objectives
C – Objective lens – scanning, low, high powers, magnify image
D – Stage Clips – holds the slide on the stage
E – Diaphragm – controls amount of light that passes through the
specimen
F – Light source – provides light
G – Ocular lens – eyepiece, magnifies light
H – Arm – carry microscope by arm and base
I – Stage – platform where the slide with specimen is placed
J – Course knob – large adjustments
K – Fine knob – small adjustments
L – Base - support, carry by arm and base
T YPE OF CELLS
Prokaryotic cell – do not have a
nucleus or membrane bound
organelles (bacteria)
Eukaryotic cell – contain a
nucleus and membrane bound
organelles (plant and animal)
CELL PARTS
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
PLANT CELL VS ANIMAL CELL
Plant Cell
 Cell Wall
 Chloroplast
 Large Central Vacuole
Animal Cell
Centrioles
Cilia / flagella
Lysosome
CELL CYCLE – cells reproduce by a cycle
of growing and dividing
Interphase – (G1, S, G2) cell spends most of its time
Mitosis – cell’s nucleus and nuclear material divides
Cytokinesis – cell’s cytoplasm divides and cell splits
into two
Interphase
G1 - growing
S – DNA duplicates
G2 – 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
MITOSIS
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
MEIOSIS
 Prophase I – homologous chromosomes condense and pair
up, crossover
 Metaphase I – homologous chromosomes line up in middle
 Anaphase I – homologous chromosomes pull apart
 Telophase I – two nuclei (cytokinesis follows) – end with 2
cells haploid number of chromosomes




Prophase II – chromosomes condense
Metaphase II – chromosomes line up in middle
Anaphase II – sister chromatids pull apart
Telophase II – two nuclei in each cell, cytokinesis follows
ending with 4 haploid cells
MITOSIS VS MEIOSIS
Mitosis
Asexual reproduction
Two identical daughter cells are created
Meiosis
Sexual reproduction
Results in genetic variation, 4 unique cells
Crossing over occurs
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
GENETICS
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)
TELL GENOTYPE
Blue body yy
Long nose LL, Ll
Stubby nose ll
Hybrid yellow Yy
Round eyes RR, Rr
Heterozygous round
eyes Rr
Oval eyes rr
Squarepants SS, Ss
Purebred blue yy
TELL PHENOTYPE
LL long nose
rr oval eye
Yy yellow body SS squarepants
Rr round eye
Ss squarepants
GENETICS PROBLEMS
Wilma Rr
Wilbur RR
R
R
RR
R
RR
r
Rr
Rr
Kids possible genotypes RR, Rr
Kids possible phenotypes round eyes
Round eyes 100%
Oval eyes 0%
GENETICS PROBLEMS
Susie - blue yy
Bob - heterozygous yellow Yy
y
Y
Yy
y
yy
y
Yy
yy
Kids possible genotypes Yy, yy
Kids possible phenotypes yellow, blue
Blue body 50%
EVENTS IN PROPER ERA
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
HISTORY OF EARTH
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 LIFE
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
EVOLUTION – cumulative changes in the
groups of organisms through time
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
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)
STRUCTURES
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)
ADAPTATIONS
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)
EXTRA
Humans have NOT always been
dominant species on earth
Biology – study of life
Bacteria – first living organism on
Earth