Download First semester notebook - Clement

Using this notebook
I. Watch videos and read book, follow along with this outline
II. Add definitions, explanations, diagrams, and examples where needed
III. Do the mapping and drawing when directed, they may be done on another sheet of paper if you
need more space, just put it in with your notes.
IV. Write questions in margins to ask for clarification back in class
V. Get parent signature to show you watched the videos/ read the book
Welcome to Biology
I. Science is used to understand how the world around us works
a. Has rules involving experimentation to test ideas
b. Provides explanation and allows us to make predictions
c. Biology- study of living organisms
i. Science we will study all year
ii. Well over 2 million species discovered and probably another 50 million out there,
we know very little about most of them
iii. You will be learning about what others have discovered and carrying out many of
your own experiments
iv. Some of our work will happen outdoors, some in the lab, and some on the
computer
Compare and contrast what you heard about science this year and what you did last year.
1.1 The Cell is the Basic Unit of Living Things
I. Living things are different from nonliving things
a. Characteristics of life
i. Organization- body put together in such a way as to function- simple as in single
cell life; complex in multicellular such as wings- flying, feet- grabbing, beakeating in birds; rocks show no organization, minerals mixed up
ii. Ability to develop and grow- grow into adult form, some have small change in
appearance- dogs; some large change- caterpillar to butterfly
iii. Ability to respond to the environment- change as environment changes; pupils
open as light decreases; flowers close up for night; animals move into shade
iv. Ability to reproduce- able to make new organisms (as a species) seeds grow into
new plants; bacteria divides
Use a map to compare and contrast living and nonliving things.
b. Needs of life
i. Energy- need energy to make chemical reactions happen in cells; most (plants and
a few others)get it from sun, some get it from eating organism that stored energy
from sun (animals); some get it from sulfur or other sources
ii. Materials- needed to develop and grow including carbon, nitrogen, oxygen, water
obtained from eating or absorbing
iii. Space- varying amounts needed to live and grow, bacteria need very small space;
bears need lots of space to find energy and materials
What is the difference between the characteristics of life and the needs of life (don’t list what they
are)? _______________________________________________________________________________
____________________________________________________________________________________
II. All living things are made of cells
a. Cells are smallest unit of living thing- trillions of cells in your body, one cell in bacteria,
cannot break cell up and have it still be alive
b. Unicellular- organism (living creature) made of only one cell; bacteria, amoeba, other
microscopic creatures- probably majority of living things
i. One cell performs all tasks needed to stay alive
c. Multicellular- single organism made of more than one cell; humans, ants, redwood trees
i. Each type of cell performs a specific task- muscle cell, skin cell, root cell
ii. Cells work together to carry out functions needed to stay alive
iii. Allows for larger organism since cells have a maximum size
Compare and contrast multicellular and unicellular organisms.
III. The microscope led to the discovery of cells
a. Robert Hooke among first to see and describe cells (1600’s)
i. Looking at cork (bark, which are dead cells) saw what looked like empty rooms
ii. Magnified 30x
iii. Highly educated, member of Royal Academy of Sciences in London (center of
knowledge time)
b. Anton van Leeuwenhoek- first to see microscopic living organisms in water
i. Made own microscopes that magnified 300x; first to see protozoa and bacteria
ii. Largely uneducated, read Hooke’s book and made own lenses, in Netherlands,
drew and described findings which were sent to Hooke and others in London
iii. Microscopes magnify to see small details
c. Cells come from other cells
i. Lots of living organisms looked at- cells found in all of them
ii. All cells come from other cells (except the first few, of course)
iii. Cell Theory (simplified version)- this is the basis of much of biology
1. Every living thing is made of one or more cells
2. Cells carry out the functions needed to support life
3. Cells come only from other living cells
d. Cell Theory helps eliminate diseases
i. Many people thought flies, molds, microorganisms appeared in meat
spontaneously (out of nothing)
ii. Louis Pasteur showed they can’t do this, but grow from ones already there
iii. Developed ways of killing bacteria (pasteurized milk) to keep food longer
Show how the understanding of cell theory helps in the fight against disease.
1.2 Microscopes allow us to see inside the cell
I. How small are cells?
a. Measured in micrometers (um)- 1/1000 of mm
b. Some bacteria- 1 um, some plant/ animal cells- 1,000 um
c. 17,000 bacteria cells across face of dime
II. The microscope is an important tool
a. Light microscope- lenses bend light to magnify object; kind we will use in class
i. Magnify up to 1,000x (ours will magnify up to 400x)
ii. Dyes make cells (or specific parts of cells) more visible
iii. Can use live specimen, small as 0.2 um
b. Scanning electron microscope (SEM)
i. See as small as 0.00002 um; magnify up to 1,000,000x
ii. Specimen must be dead- gets coated with heavy metal such as gold
iii. Image appears 3D- electrons bounced off metal coating to detector
c. Transmission electron microscope
i. See as small as 0.00002 um; magnify up to 1,000,000x
ii. Specimen sliced very thin, electrons pass through specimen to detector
iii. Images appear 2D
Construct a map comparing/ contrasting the 3 types of microscopes found above:
Cells are diverse
I. Cells are classified by the structures found within them
a. Cell membranes- surrounds cells and determines what goes in and out
b. Cytoplasm- gelatin like material within cell where much of action happens
c. Organelle- structure within cell that is separated from cytoplasm by membrane- nucleus,
chloroplast, etc
d. Genetic material (DNA or RNA)- found within either cytoplasm or within another
membrane in the cytoplasm
i. Prokaryotic cells- most of the genetic material within cytoplasm- most
unicellular organisms like bacteria
ii. Eukaryotic cells- most of the genetic material within nucleus, most multicellular
organisms like humans and plant (mitochondria and chloroplast also have DNA)
e. Nucleus- where most of the genetic material is in a eukaryotic cells
II. Plants and animal cells are eukaryotic cells
a. Both plant and animal cells have:
i. Nucleus- holds much of the genetic material which has the directions for what is
built in/by the cell (proteins)
ii. Endoplasmic reticulum- has ribosomes, builds cell membranes, parts break off,
form vesicles
iii. Ribosomes- translate the genetic material into something usable (proteins)
iv. Vesicles- storage and transport of material
v. Golgi apparatus- finishes construction of some material
vi. Mitochondria- use oxygen to get energy out of food and to the rest of the cell
vii. Vacuoles- storage containers
b. Plant cells have:
i. Chloroplasts- use energy from sun to combine CO2 and H20 as sugars
ii. Cell walls- tough outer covering that lies just outside cell membrane, supports
(think tall trees) and protects cells
iii. Central vacuole- large storage container, takes up much of cell- holds water and
other materials
c. Animal cells have:
i. Lysosomes- hold materials and break them down including old cell parts and
materials taken in
On a separate page, construct a map that gives an analogy of what each part of a cell is like such
as the mitochondria is like a power plant or the nucleus is like a brain. Construct 2 brace maps
showing which organelles are found in plants and which are found in animals.
1.3 Cells can perform specialized functions
I. Organisms can be classified by their cell type
a. Classifying (putting into groups) makes it easier to make sense of the millions of types of
organisms on earth- imagine shopping in a grocery store where everything is put on the
shelves in random places.
b. Domains- large classification groups which have many smaller groups in it
i. Archaea- unicellular organisms, prokaryotic cells (prokaryotes)
ii. Bacteria- unicellular organisms with prokaryotic cells (prokaryotes), cytoplasm
has only ribosomes as organelles, simple structure, many have tough cell wall
iii. Eukarya- cells have nucleus, include plant, animal, fungi, and protists
II. Cells in multicellular organisms specialize
a. Specialization means each cell has a particular function
i. Different organisms have different levels of specialization
1. Blood cells deliver oxygen, fight infections, move waste but can’t move
the body like a muscle cell
ii. Unicellular organisms- one cell does it all
III. Multicellular organism is a community of cells
a. Cells work together to accomplish a task
b. Tissues- a group of similar cells organized to do a specific job; top layer of skin is one
type of skin tissue
c. Organs- different tissues working together to perform a function; eye is an organ made
of a variety of tissues (we will see this when we dissect one at the end of the year); leaf is
organ that is made of different tissues
d. Organ system- organs and tissues working together; Humans have about 40 organs
making up about 10 organ systems; plants have only a few organ systems
e. Organism- all organ systems working to meet characteristics and needs of life; you are
one organism
Create a pyramid that shows the levels of organization and gives an example of each level.
IV. Scientists use models to study cells
a. Difficult to study because of size; molecules in cell even small and harder
b. Shape of molecules affect how they behave
i. Rosalind Franklin used x-rays to image DNA
ii. James Watson and Francis Crick constructed 3-D model
iii. Understanding of DNA and what it does made easier after the shape was
discovered (we will do this soon)
Chapter 2 How Cells Function
2.1 Chemical reactions take place inside cells
I. All cells are made of the same elements
a. You are what you eat- body made out of what you eat
b. Atoms are building blocks of everything- look on periodic table to see complete list
(gold, hydrogen, oxygen…); elements not made of other things
c. Atoms bond to make molecules (like cells making up tissues)
d. About 25 elements important in body- most important 6 are carbon (C); hydrogen (H);
oxygen (O); nitrogen (N); phosphorous (P); sulfur (S)- mnemonic- CHONPS
e. Chemical reactions- molecules broken apart and new types made- energy taken in and
given off; allows you to think, move, stay alive- everything you do is result of chemical
reactions in cells
II. Macromolecules (large molecules) support cell function- 4 main types
a. Carbohydrates- made of subunits of sugars; used for energy or making structures;
i. Simple carbohydrates- made of C, H, and O- from plants- broken down for
energy
ii. Complex carbohydrates- long chains of sugars; form starch, cellulose, glycogen
1. Plants store extra sugars as starch; cellulose used for cell walls
2. Break down into sugars to get energy back
b. Lipids- fats, oils, waxes
i. made of C, O, H; often have long chains (tails) of C attached to glycerol
ii. most do not dissolve in water
iii. used for energy and making structures
c. Proteins- strings of amino acids
i. Amino acids made of C, O, H, N, S; make long chains which fold up;
ii. Amino acids taken from food you eat or made by body, get rearranged to make
the proteins you need; all organisms have protein
iii. Used as enzymes to control chemical reactions; growth and repair; allow muscles
to move; fight infections; delivers oxygen; found in cell membrane and transport
materials in and out; much more
d. Nucleic acids- hold instructions for cells to develop, grow, and reproduce
i. DNA and RNA- the NA is for nucleic acid, the D and R are types of sugar
ii. Long chains of nucleotides made of C, H, O, N, P
iii. Tells cell how to make proteins; code is in nucleotide pattern in DNA or RNA
III. About 2/3 of every cell is water
a. Chemical reactions (which allow you to do what you do/think) take place in water
b. Water molecules are polar (think North and South pole of a magnet)- have 2 positive
ends (H) and 1 negative end (O);
c. Other polar molecules are attracted (positives to negatives) and dissolve in water;
nonpolar molecules (lipids) are not attracted and do not dissolve (think oil and water do
not mix)
d. Cell membrane made of double layer of lipids with polar heads and nonpolar tails- tails
point in and heads point out (draw this to help you remember)
Construct a map that has all four types of macromolecules and what they do.
2.2 Cells capture and release energy
I. All cells need energy to function
a. Use chemical energy- stored in bonds holding atoms together in a molecule
b. Sugar molecules, such as glucose, commonly used to get energy
c. Being alive uses energy, eating resupplies molecules used for energy
d. Most plants and a few other organisms able to capture sunlight; other organisms
(particularly archaea) able to use other sources
Draw/write a sequence of events showing how sunlight gets used by animals as energy.
II. Some cells capture light energy
a. Most energy starts with sun (a few organisms use sulfur or other compounds)
b. Photosynthesis- plants store light energy from sun as chemical energy in glucose (note
this is a simplified version of photosynthesis, but a good start)
i. Chloroplast- organelle where photosynthesis occurs
ii. Chlorophyll- pigment (color molecule, green in this case) that absorbs sunlight
iii. Reactants (starting materials)- carbon dioxide (CO2) from air and water (H2O)
from soil
iv. Reaction- CO2 and H2O enter chloroplast, chlorophyll absorbs energy from sun,
energy used to rearrange atoms to form products
v. Products (result of chemical reaction)- oxygen (released in air) and sugar (used
or stored linked together as a starch for later use)
Draw diagram that shows the photosynthesis process including reactants, process, products.
III. All cells release energy
a. Sugars, proteins, and lipids provide energy for processes in cells such as making new
molecules, moving molecules into or out of cells, sending signals between cells, ….
b. Energy released through cellular respiration (with oxygen, releases more energy) or
fermentation (no oxygen needed)
c. Cellular respiration- use oxygen to release energy from sugars
i. Mitochondria- organelle where cellular respiration occurs
ii. Reactants- oxygen and sugar
iii. Process- glucose in cytoplasm breaks down into smaller molecules (some energy
released), in mitochondria oxygen combines with hydrogen as molecules continue
to break down releasing more energy
iv. Products- H2O and CO2(released to air) and energy (transferred to where needed
by other molecules or released as heat)
Draw a diagram showing cellular respiration including reactants, process, and products
Draw a diagram showing photosynthesis and cellular respiration as a cycle
d. Fermentation- cells release energy without using oxygen
i. Occurs in cytoplasm- glucose breaks into smaller molecules releasing energy
ii. Alcoholic fermentation- products are alcohol and carbon dioxide;
I. used to make bread
II. yeast eats sugar, CO2 makes bread rise, alcohol evaporates
iii. Lactic acid fermentation- product is lactic acid
I. Lactic acid from bacteria cause sour taste in sourdough bread
II. Lactic acid from bacteria causes milk to thicken into yogurt or cheese
From video or p. 54 in text, draw a diagram or map showing processes your body uses at
various points while exercising.
2.3 Materials move across the cell’s membrane
I. Some materials move by diffusion- process by which molecules spread out from lots in an
area to where there are few; happens through random motion of the molecules
a. Spray perfume molecules- strong smell near you, no smell far away faint smell
everywhere
b. Concentration- number of particles in a specific volume
i. 9 grams of sugar in 1 liter water  9g/ liter; 10 g sugar in 5 liters water  2
g/ l
ii. diffusion goes from high concentration to low; greater difference, faster
diffusion
c. Diffusion in cells- one way some molecules move in and out of cells
i. Photosynthesis produces oxygen in cell concentration in cell greater than
concentration outside cell oxygen diffuses out of cell
d. Passive transport- materials move in and out of cell without energy being needed
i. Some molecules move through cell membrane between lipids
ii. Some molecules slide through proteins in cell membrane designed for just
that molecule
iii. Osmosis- diffusion of water through a membrane (such as cell membrane)
iv. Goes from high concentration to low concentration
v. Partly explains wilting in plants/ wrinkly skin in a pool or bathtub
(concentration is not just how much water, but also how many salts are in
the water, goes from pure water to less pure water- into body)
e. Active transport- movement of materials requiring energy
i. Needed to go from low conc. to high conc., or move large molecules across
a membrane
ii. Some cells use energy to move molecule through protein in membrane
Ex._________________________________________________________
iii. Endocytosis- move large molecule into cell by surrounding with membrane
which breaks off inside ex. _____________________________________
iv. Exocytosis- move large molecule out by taking package of molecules,
membranes merge, and molecule is released
Draw endo- and exo- cytosis as a series of events based on video or p. 61 in text
Cell Division
3.1 Cell division occurs in all organisms
I. Cell division is involved in many functions
a. Unicellular organisms divide to reproduce- each new cell is a separate individual
b. Multicellular organisms grow, develop, repair, and reproduce through division
c. All living things (you, ant, oak tree) start out as one cell
i. Growth- due to cells growing then dividing then growing then dividing
1. Ex. _______________________________________________
ii. Development- as new cells added, specialize and tissues/ organs/ organ
systems develop
1. Ex. ______________________________________________
iii. Repair- injuries repaired and dead cells replaced by division
1. Ex. _______________________________________________
Draw a map showing a sequence of events that would require division for growth,
development, and repair.
3.2 Cell division is part of the cell cycle
II. The cell cycle includes interphase and cell division
a. Cell cycle- normal sequence of development and division of a cell
i. Interphase- normal functions of cell carried out, longest phase
1. Grows about twice size
2. Normal functions of cell happen (respiration, material transport…)
3. DNA replicates itself
ii. Cell division- mitosis (division of nucleus in eukayotic cells) and
cytokinesis (cell becomes two separate cells)
iii. Mitosis- part of cell cycle where nucleus divides
1. Prokayotes do not go through mitosis because __________________
2. Moves DNA into position for cell division so that each daughter cell
has a complete copy of the DNA
iv. Cytokinesis- division of parent cell’s cytoplasm into daughter cells
v. Interphase begins again in each new cell
vi. Daughter cells- genetically identical cells from parent cell (nothing to do
with male of female)
Draw a pie chart and place interphase, mitosis and cytokinesis with pie pieces showing
amount of time spent by the cell in each phase.
III. Cell division produces two genetically identical cells
a. Mitosis has 4 phases
i. Prophase- long strands of DNA condense by wrapping around proteins and
are called chromosomes
1. Chromosomes are still DNA, just in a specific shape
2. Chromosomes have two chromatids connected by the centromere,
(during interphase the DNA replicated, or made copies of itself)
ii. Metaphase- chromosomes line up in middle of cell, centrioles and spindles
form and attach to _____________
iii. Anaphase- chromosomes pulled apart so that each new cell will get one
chromosome that is identical to the other cells (these were copied during
interphase)
iv. Telophase- new nuclear membrane forms around each group of
chromosomes
b. Cytokinesis- cytoplasm and organelles divide so that each new cell will get some,
cell pinches and separates in two
i. Animal cells- fiber ring in middle contracts pulling membrane in and
pinching cell in two
ii. Plant cell- cell plate grows in middle of cell and becomes part of membrane
and cell wall separating the two cells (what prevents the a plant cell from
being pinched in two? ________________________________________)
In class we will draw these steps so that you can have visuals in your notebook. Right now,
construct a tree map for the cell cycle- interphase, mitosis, and cytokinesis- and what
happens in each.
3.3 Both sexual and asexual reproduction involve cell division
I. Asexual reproduction involves one parent- unicellular organisms
a. Each cell results in a new organism that can live independent- offspring
b. Skin cells dividing do not make offspring, the new skin cell must stay part of the
organism
c. Offspring are identical to the parent
d. Cell division- one form of asexual reproduction
i. Binary fission- prokaryotes (without nucleus) replicated DNA then split in
two; bacteria and archaea
ii. Cell division (with mitosis and cytokinesis)- unicellular eukaryotes (with
nucleus); algae, protozoans, some yeasts
What determines if a unicellular creature uses binary fission or cell division? ____________
e. Budding- bud (outgrowth) forms and develops into genetically identical version of
the parent
i. bud usually breaks off into separate organism
ii. unicellular (yeast) and multicellular (hydras and a few plants)
II. Regenerationa. process by which missing body parts replaced by the growth of new tissue
b. Sometimes broken off piece grows into new organism- some sea stars, many plants
III. Generation time- amount of time needed for new offspring to produce new organism
a. asexual reproduction can have fast generation times- as little as 20 minutes
b. allows population to grow quickly- seen in spoiling food and fast moving sore
throats
c. if a bacteria infection starts with 1 organism and a generation time of 20 minutes,
how many will be there after 5 hours? ___________________
IV. Sexual reproduction involves two parent organismsa. genes of two parents combined to produce offspring not identical to either parent
b. gives greater diversity, more complex process, generally longer generation times
Use mapping to relate the type of reproduction with the kinds of organisms that use it and
how the offspring’s genes relate to the parents.
Patterns of Heredity
4.1 Living things inherit traits in patterns
I. Parents and offspring are similar but not identical
a. Sexual reproduction allows cell to have genetic information from each parent
b. Traits – characteristics of an individual organism; brown fur, blue eyes, taller
(what are some traits you have? ____________________________________)
c. Inherited traits- given to you by your parents through DNA
d. Acquired traits- developed during lifetime; learned behaviors (ability to read,
throw a ball)
e. Inherited and acquired traits affect each other- some peoples genes set them up for
throwing a ball harder or make it easier for them to learn to read. A new field
called epigenetics is showing how the environment we live in or what we do can
affect genes- particularly over a few generations.
Draw a diagram to show how acquired and inherited traits might be passed from parent to
child.
II. Genes are on chromosome pairs (get the vocabulary down)
a. Gene- segment of DNA at a specific location on a chromosome that influences
hereditary characteristics
i. has a code for a specific trait; often more than one gene needed to
determine trait; “genes that code for eye color”
b. Heredity- passing of genes from parents to offspring
i. Inherit the gene not the trait; may get different gene from other parent
ii. Most eukaryotes have pairs of chromosome, one given to them from each
parent- chromosome 1 from parent A and chromosome 1from parent B
(humans have 23 chromosome pairs); they have genes for the same traits
though the genes may not say the same thing (two cook books with
different recipes for sugar cookies), each pair has different genes than
another pair
iii. Homolog- each member of a chromosome pair; chromosome 1 from
parent A is one homolog, chromosome 1 from parent B is other homolog
of the pair that are in most cells in the body.
iv. Alleles- different forms of the same gene; one height gene is for tall and
another height gene is for short, they are different alleles of the same gene
(note: it actually takes multiple genes (more than one) as well as the
environmental effect to code for height)
c. Chromosome number- # of chromosomes for a species (type of organism),
humans have 46 (23 pairs), chimpanzees have 48 chromosomes (24 pairs), fruit
flies have 8 (4 pairs)
d. Human sex chromosomes- determine gender of the individual- pair 23
(numbered for easy reference);
i. Two possibilities- X chromosome or Y chromosome (named for their
shape
ii. Females inherit an X chromosome from each parent  XX; males inherit
an X from mother and a Y from father  XY
Draw chromosomes and label for an imaginary species with 6 chromosomes (3 pairs).
Include chromosome, homolog, gene, and allele.
III. Gregor Mendel made some important discoveries about heredity
a. Gregor Mendel- monk in Austria; studied math and science at university and
applied knowledge to study inheritance of traits in pea plants
b. Studied seven traits- plant height, flower and pod position, seed shape, seed color,
pod shape, pod color, flower color
c. True breeding- plant that always produces offspring with same trait it has when
pollinated with itself
d. Experiment
i. One true breeding for regular height and another for dwarf height- crossed
with self, offspring just like parent
ii. Crossed with other (pollinated by hand), all offspring regular height (these
are F1 or first generation)
iii. F1 generation self pollinated- ¾ regular height, ¼ dwarf height
iv. Conclusion- each plant has two genes (he called them factors) for the
height trait
1. If both genes regular or one regular-one dwarf  plant regular
2. If both genes dwarf  plant dwarf
Draw a diagram that shows 1 true breeding regular crossed with 1 true breeding dwarf
and what the offspring would look like. Include alleles of the gene and draw what happens.
IV. Alleles interact to produce traits
a. Phenotype- characteristics that are actually on the organism (color eyes they
have, height they are, number of legs)
b. Genotype- alleles organism has in the DNA (might have necessary genes for blue
eyes and brown eyes- that is its genotype)
c. Dominant allele- allele is expressed (used, shows up in phenotype) even if only
one is present, “silences” other allele (eyefold allele is dominant over no-eyefold
allele)
d. Recessive allele- expressed in phenotype only if it is only allele present (noeyefold phenotype found only when two no-eyefold alleles are present, one from
each parent, one on each homolog in the chromosome pair)
e. many traits coded for by multiple genes and one is not always dominant or
recessive, can have “mixtures”
Use a map to show the difference between genotype and phenotype, use a diagram to show
how dominant and recessive alleles work.
4.3 DNA is divided during meiosis
I. Meiosis is necessary for sexual reproduction
a. Two cells combine during sexual reproduction- genetic information from each
parent is found in the new cell
i. Humans have 46 chromosomes- 23 pairs in most cells
ii. Diploid cell (2n)- cells with 2 sets of chromosomes, n is number of
chromosomes in one set (humans this would be 23, so 2n is 46; fruit flies
n= 4 so 2n is 8)
iii. Gametes- sex cells that contain just one set of chromosomes, cells are
haploid having half the regular number of chromosomes
1. human gametes have 23 single chromosomes, fruit fly gametes
have 4 single chromosomes, no pairs
2. found in reproductive organs (usually)
3. egg- female gamete
4. sperm- male gamete
5. Fertilization- gametes combine to form one cell called zygote
6. Egg contributes genetic material, cytoplasm w/ organelles, sperm
contributes just genetic material
7. Zygote is now 2n
Draw a diagram with labels showing a male gamete and a female gamete from a species
with n=3 forming a zygote. Make sure you show the chromosomes.
II. Cells divide twice during meiosis (meiosis overview follows, details later)
a. Before meiosis begins, DNA is replicated (copied)
i. 2 chromosomes each with each having 2 chromatids 4 chromatids
ii. Meiosis has two cell divisions without replication in between
iii. 1 cell 2 cell divisions (1/2 then ½ again) 4 daughter cells each with
one chromatid
Try drawing this starting with one cell that has already replicated its DNA so it has two X
in it.
III. Meiosis
a. Meiois I
i. Prophase I- chromosomes condense, nuclear membrane breaks down
ii. Metaphase I- chromosome pairs line up
iii. Anaphase I- Chromosome pairs separate- alleles divided
iv. Telophase I- nuclear membrane reforms
v. Cytokinesis- cell divides
b. Meiosis II
i. Prophase II- cells prepare to divide
ii. Metaphase II- chromosomes line up
iii. Anaphase II- chromatids separate
iv. Telophase II- nuclear membrane reforms
v. Cytokinesis- cells divide  four daughter cells each with one chromatid
having one version of each allele
We will draw this in class. Use a map to compare and contrast meiosis and mitosis.
IV. Combinations of alleles
a. Offspring receive different combinations of alleles than their parents have because
they receive one from each parent, and the parents are different from each other
b. Crossing over also happens between chromosomes before meiosis
4.4 Cells use DNA and RNA to make proteins
I. DNA is the information molecule
a. DNA makes nothing- carries “recipes” for making proteins
b. Proteins are involved in most of the work and structure of a cell
II. Proteins and amino acids
a. Large molecules made of chains of amino acids
b. 20 different amino acids arranged to make thousands of different proteins
c. lysozyme- 129 amino acids, kills bacteria
d. dystrophin- large protein in muscle has 3685 amino acids in chain
e. DNA Shape- twisted ladder, double stranded spiral, helix
i. Nucleotides combine to make DNA
ii. One part of nucleotide forms a side rail, the base makes ½ a rung- this
combines with another nucleotide to complete the rung and add the other
side rail; many of this in order make the molecule
iii. 4 possible nucleotides: adenine (A), thymine (T), cytosine (C), guanine
(G). A and T always pair and C and G always pair
iv. Genes come from the proper order of nucleotides- CAG codes for amino
acid glutamine, GAC codes for the amino acid aspartic acid
III. Replication produces two copies of DNA
a. DNA is copied during interphase
i. The strands unzip separating in the middle of each rung
ii. The companion base joins up (A-T and C-G)
iii. Now two copies of the DNA
Draw the sequence of events that happens in replication.
IV. RNA is needed to make proteins
a. DNA- deoxyribonucleic acid; RNA- ribonucleic acid
b. Types of RNA( all RNA use uracil (U) instead of thymine (T)
i. Messenger RNA (mRNA)- forms copy of DNA in nucleus
ii. Transfer RNA (tRNA)- attaches to amino acids (each tRNA gets a
different type of amino acid)
iii. Ribosomal RNA (rRNA)- brings the other two RNAs together to form the
chain
Classify the types of RNA
c. Transcription- process of transferring DNA recipe to mRNA
i. DNA opens at gene
ii. mRNA is built by base pair matching on one strand only
iii. DNA closes and mRNA moves into cytoplasm to make proteins
d. Translation- RNA is used to make protein
i. Nucleotide sequence used to build amino acid sequence making a protein
ii. mRNA brings the recipe; rRNA is the kitchen where it happens; tRNA
gathers the ingredients
iii. tRNA- one part attaches to amino acid, one end attaches to mRNA in
correct spot, rRNA attaches the amino acids and separates them from the
tRNA
iv. Proteins made at the correct time and place determine individual’s traits
Show (draw or describe) the sequence of events from DNA to protein.