Keystone Review Day 4
Basic Principles
Characteristics of Life
1. Organization- all organisms are organized into cells,
compartments, organelles
2. Response to stimuli - respond to touch, excess heat,
internal or external factors
3. Homeostasis- maintain stable internal conditions (heat, O2
levels, pH)
4. Metabolism- all chemical reactions that take place (mainly
making or breaking down food)
Levels of Organization
Cells- Smallest unit of life that can perform all functions
Tissues – group of cells with similar function (muscle tissue,
nervous tissue, epithelial)
Organs- Groups of tissues with specialized jobs (Liver, brain,
heart)
Organ systems- Groups of organs with a specific function
(Cardiovascular, nervous, digestive)
Organism (multicellular)- Many structures working together to
maintain homeostasis
Characteristics of Life
5. Growth & development- all organisms
grow (cell division = increase in # of cells)
and develop (become an adult through
differentiation)
6. Reproduction (either sexual or asexual)
7. Change over time (evolve for survival)
Viruses are NOT considered living!!!
Cannot reproduce or respond
to stimuli
No metabolism
No growth
Cell theory states that
A. All living things are composed of cells.
B. New cells are produced by existing cells
C. Cells are the basic unit of structure and
function in living things
D. All of these answers are correct
There are many criteria that are used to define living
things. Living things reproduce, grow, and develop.
They respond to stimuli, use materials and energy, and
evolve and adapt over time to their environment. What
is another criteria used to define living things?
A. All living things are intelligent
B. All living things are able to move
C. All living things are made of cells
D. All living things are complex
This virus consists of a single strand of DNA enclosed in
a protein capsule. Is this virus considered a living
organism?
A.No; living organisms must have two characteristics of
life, and the T4 bacteriophage only has one.
B.Yes; since the virus contains DNA, it is a living
organism.
C.No; viruses are not considered to be living organisms.
D.Yes; since the virus contains protein, it is a living
organism.
DNA
2 strands
Sugar= deoxyribose
Base = Thymine (T)
Instructions to make
proteins
Stays in nucleus
RNA (copy of
DNA)
1 strand
Sugar = ribose
Base = Uracil (U)
Helps to create
proteins
Can leave nucleus
Both
- Made of nucleotides
(monomer)
 Sugar, phosphate,
Nitrogenous base
-Phosphate group
- Bases = Adenine,
Guanine and Cytosine
Base Pairing Rules for
DNA – DNA
A–T C–G
Base Pairing Rules for
DNA – RNA
A–U C–G T–A
DNA: TAG – CAA – TTC – GAA
DNA:
DNA: TAG – CAA – TTC – GAA
mRNA:
DNA Replication (copy DNA)
Final Product: 2 identical copies of DNA with 1
new and 1 old strand (semi-conservative)
Why? Need to double DNA for Cell Division
When? During S-Phase of Interphase
Where: In Nucleus
Enzymes Used:
1. Helicase- unzips DNA
2. DNA Polymerase- lays down nucleotides to
create new DNA strand
A parent DNA molecule replicates, resulting in two
daughter DNA molecules. Which of the following is true?
A. Each daughter molecule contains two new strands of
DNA.
B. Each daughter molecule contains two DNA strands
from the parent molecule.
C. Each daughter molecule contains four total strands of
DNA.
D. Each daughter molecule contains one DNA strand from
the parent molecule.
The DNA sequences that make up the genetic code of an organism determine
which traits the organism will exhibit.
How are the instructions coded by DNA translated into an organism's physical
traits?
A. Instructions coded by DNA sequences are translated into proteins which
express an organism's physical traits.
B. Instructions coded by DNA sequences are translated into nucleotides which
express an organism's physical traits.
C. DNA sequences both code genetic instructions within an organism and
express an organism's physical traits.
D.DNA sequences that code for genetic instructions attach to phosphate groups
that express an organism's physical traits.
3 TYPES OF RNA
1. mRNA = copy of DNA made
during transcription
2. tRNA = Carries amino acids
to ribosome during
translation to make a protein
3. rRNA = Makes up
ribosomes
Protein Synthesis (making of proteins)
** ALL ORGANISMS UNDERGO
PROTEIN SYNTHESIS AND USE
INSTRUCTIONS FROM THE
BASE PAIRING CODE IN DNA
2 Steps: Transcription &
Translation
Central Dogma:
DNA  RNA  Protein
1. Transcription
Location: Nucleus (cytoplasm in
prokaryotes)
Purpose: DNA  mRNA
Make a mRNA copy of DNA
instructions to allow the instructions
to leave the nucleus
How?: RNA Polymerase attaches to
DNA, reads DNA and creates matching
mRNA strand  sent to ribosome
1. Given DNA Sequence:
DNA: ATG ACC TAA
2. Given mRNA Sequence:
ACU UAA GUU
Terms:
Codon = every 3 bases on the
mRNA  Each codon codes
for 1 amino acid
Anti- codon = every 3 bases
on the tRNA 
Complimentary (matches) the
mRNA codon
2. Translation
Location: Ribosome
Purpose: mRNA  Protein
Make a protein from mRNA
instructions
How?: Ribosome reads mRNA (codon)
Calls for matching tRNA (anti-codon)
Amino is brought to ribosome and
attached to other amino acids to
create a protein
Amino Acid Chart
DNA: ACT GAC
mRNA:
Amino Acid:
Amino Acid Chart
DNA: TTA CAT
mRNA:
Amino Acid:
Amino Acid Chart
DNA: GGC ATA
mRNA:
Amino Acid:
Amino Acid Chart
DNA: GCT ACC
mRNA:
Amino Acid:
What kind of mutation will result from the mistake made during DNA
replication in the nucleotide sequence above?
A. nonsense mutation
C. chromosomal mutation
B. silent mutation
D. frame shift mutation
How is the nucleus involved in the production of
enzymes?
A. The nucleus transcribes and releases messenger RNA signaling for the
enzymes to be synthesized.
B. The nucleus receives the messenger RNA and is the site where
enzymes are synthesized.
C. The nucleus is involved in the packaging and transportation of
enzymes outside of the cell
D. The nucleus translates the ribosomal RNA for the enzymes to be
synthesized in mitochondria.
During a stage of protein synthesis, codons in
mRNA molecules are used to specify the sequence
of amino acids in polypeptide chains. What is this
process called?
A. Transcription
B. Translation
C. Codification
D. Gene Expression
What is a major difference between DNA replication and DNA
transcription?
A. RNA molecules produced by transcription are much shorter in
length than DNA molecules produced by replication.
B. DNA replication involves the nitrogenous base uracil, while
DNA transcription involves the nitrogenous base thymine.
C. DNA transcription only occurs in multicellular organisms,
while DNA replication occurs in all organisms.
D. DNA replication takes place in the nucleus, while DNA
transcription takes place in the cytoplasm.
Translation involves the assembling of proteins.
Which of the following forms of RNA is
responsible for carrying a formed amino acid to
the protein assembly site during translation?
A. rRNA
B. RNA polymerase
C. tRNA
D. mRNA
DNA contains instructions for making the
different molecules that a cell needs to grow
and function. For example, _______ is made
by _______.
A. a protein; translating mRNA
B. mRNA; translating DNA
C. mRNA; transcribing proteins
D. a protein; transcribing mRNA
Which of the following is true about DNA transcription and
protein translation?
A.Transcription only occurs in animal cells, whereas
translation only occurs in plant cells.
B.The processes of transcription and translation do not
occur in prokaryotes.
C.The processes of transcription and translation are similar
in all living organisms.
D.Transcription only occurs in plant cells, whereas
translation only occurs in animal cells.
Mitosis
Meiosis
# of Divisions
1
2
Purpose:
Type of Cell It Occurs In:
Asexual reproduction for
growth & replacing dead cells
Somatic cells
Sexual reproduction to create
gametes & genetic variation
Reproductive cells
# of Cells Produced:
2
4
Daughter cells haploid or
diploid:
Relationship of Daughter Cells
to Parent Cells:
Diploid
Haploid
Parents identical to daughter
Daughter cells a mix of each
parent
Daughter cells identical to
each other
Unique
Relationship of Daughter Cells
to Each Other:
Terms:
Diploid = 2 sets of chromosomes
Haploid = 1 set of chromsomes
Mitosis = division of the cell’s nucleus
Cytokinesis = division of the cells’ cytoplasm
Homologous chromosomes: 4 chromatids; Same size/gene pattern/shape but not
identical (1 from each parent)  Found only in Meiosis I
Sister chromatids: 2 chromatids; Identical copies of a chromosome  Found in
Meiosis II & Mitosis
Nondisjunction: When chromosomes fail to separate properly during meiosis
Cell Cycle
A. Interphase = cell growth
G1 = Growth
S = DNA replicating
G2 = Prepare for division
B. M phase = cell division
1. Mitosis – division of nucleus
a) Prophase – DNA condenses into chromosomes; nuclear membrane
disappears; spindle fibers appear
b) Metaphase – Sister chromatids line up on metaphase plate
c) Anaphase – Sister chromatids separate to opposite ends of cell
d) Telophase – DNA unravels into chromatin; nuclear membrane begins to
reform; spindle disappears
2. Cytokinesis – division of cytoplasm
Interphase  DNA replicates
** = genetic variation
Meiosis I
Prophase I – DNA condenses into chromosomes; nuclear
membrane disappears; spindle forms
** Synapsis occurs (homologous chromosomes line up to
form tetrads)
** Crossing Over occurs (homologous chromosomes
exchange DNA)
Metaphase I – **Independent assortment occurs
(homologous chromosomes line up randomly on
metaphase plate)
Anaphase I – Tetrads separate to opposite ends of cell
Telophase I – Each sister chromatid unravels backs into
chromatin; nuclear membrane reforms
End Result: 2 diploid cells
Meiosis II
Prophase II – DNA condenses into
chromosomes; nuclear membrane
disappears; spindle forms
Metaphase II – Sister chromatids
line up at metaphase plate
Anaphase II – Sister chromatids
separate to opposite ends of cell
Telophase II – Each chromatid
unravels backs into chromatin;
nuclear membrane reforms
End Result: 4 haploid cells
(gametes- sex cells)
The cell cycle involves the growth,
replication, and division of a
eukaryotic cell. Mitosis most
directly plays a role in:
A. the transport of nutrients within a cell.
B. the division of a cell's nucleus.
C. the growth of a cell after cell division.
D. the metabolic processes of a cell.
What is the name of the process that appears
in the diagram below?
A.Differentiation
B.Meiosis
C.Mitosis
D.Fertilization
Which of the following statements describes Meiosis?
I. Produces sex cells with a half set of genetic
information
II.Produces somatic cells for growth & repair
III.Produces 4 genetically unique cells
IV.Produces 2 identical diploid cells
A.I and III only
B.II and III only
C.I, II, III, and IV
D.II, III and IV only
Kangaroos have 12 chromosomes in their
body cells. A kangaroo sex cell divides by
meiosis. The daughter cells produced each
have _______ chromosomes.
A. 18
B. 12
C. 6
D. 3
Gametes in humans are haploid. This means that they have
half the number of chromosomes as normal body cells.
Sometimes, the gamete of a male and the gamete of a female
combine to form a zygote that will eventually turn into a fetus.
Phenotypic changes in a fetus may result
A. only if a mutation occurs in both the mother's and father's
cells.
B. if a mutation occurs in the father's heart cells.
C. if a mutation occurs in the mother's brain cells.
D. if a mutation occurs in the gametes.
Which part of
the apple flower
produces cells
by meiosis?
A. style
B. anther
C. stigma
D. filament
2.Patau syndrome can be a lethal genetic disorder in mammals, resulting
from chromosomes failing to separate during meiosis.
A. Identify the step during the process of meiosis when
chromosomes would most likely fail to separate.
B. Describe how chromosome separation in meiosis is different
from chromosome separation in mitosis
C. Compare the effects of a disorder caused by chromosomes
failing to separate during meiosis, such as Patau syndrome, to
the effects of chromosomes failing to separate during mitosis.
A. Anaphase (when chromosomes separate)
B. In Meiosis – Chromosomes separate twice (homologous
chromosomes separate in Anaphase I and sister chromatids
separate in Anaphase II) to result in 4 unique half sets of
chromosomes
In Mitosis- Sister chromatids separate once to result in 2 identical
sets of chromosomes
C. When chromosomes fail to separate during Meiosis
(nondisjunction), these chromosomes changes will be passed on
the offspring.
When chromosomes fail to separate during Mitosis, these
changes will not be passed off to offspring.
A Trichoplax is a simple multicellular animal that
lives in water. This animal can reproduce asexually
by simply dividing into two organisms.
Describe a cellular division process that could be
used by Trichoplax when it reproduces asexually.
Binary fission  Replicates itself and DNA,
then divides into 2 identical organisms
.
B.
Describe one benefit and one limitation
of how the Trichoplax can reproduce by
simply dividing.
Benefit = It can reproduce by itself and increase
the population rapidly. A limitation = no genetic
variation to possibly gain traits better suited for the
environment
Mutation- changes in DNA which cause changes in
protein shape or function = changes in traits
1. Silent = Change in DNA does not affect the codon or the
protein
2. Nonsense = Change in DNA causes the codon to change
from coding for an amino acid to coding for STOP
3. Frameshift = Inserting or deleting a base which changes
the reading frame of view; changes multiple codons
Ex: Original DNA: GAT ATA
Mutated DNA: GAC TAT A
◦ Original mRNA: CUA UAU
Mutated mRNA: CUG AUA U
Inheritance Patterns
1. Complete Dominance- one allele is completely dominant over the
other allele; Heterozygote displays the phenotype of the dominant allele
2. Incomplete Dominance – neither allele is dominant enough to
overtake the other; Heterozygote displays a blended phenotype
3. Codominance – Both alleles are equally dominant; Heterozygote
displays both alleles equally (usually spotted)
4. Sex-linked – Found on the sex chromosomes; Sex-linked recessive
more common in males (have only 1 X) (Colorblindness)
5. Multiple Alleles – More than 2 alleles (Blood type)
R = Red flower
r = white flower
Heterozygote Phenotype (Rr)
Complete Dominance
Red
Incomplete Dominance
Pink
Codominance
Red & white spotted
Which statement best describes the relationship
between an allele and a gene?
A. An allele is a variation of a gene that can be
expressed as a phenotype.
B. An allele is the part of a gene that attaches to
messenger RNA molecules.
C. An allele is a segment of a DNA molecule that
controls replication of a gene.
D. An allele is the primary protein made by a gene
found in a developing embryo.
A genetic mutation that causes a codon that should
code for a specific amino acid to be changed into a stop
codon results in a shortened protein product and is
known as
A. A Frame shift Mutation
B. A Nonsense Mutation
C. A Silent Mutation
D. A chromosomal Mutation
A trait in cows is determined by two alleles of
a single gene: allele R is dominant, and
allele r is recessive. What is the probability of
the dominant trait being expressed in the
offspring of one RR parent and one rr parent?
A. 25%
B. 50%
C. 75%
D. 100%
Overuse of antibiotics has caused antibiotic resistance in some
bacteria in a population. Which statement describes the most
likely impact of natural selection on the bacterial population?
A. Beneficial mutations have decreased, resulting in a larger
population than normal.
B. Only the genes for antibiotic resistance are now expressed,
eliminating other genes.
C. More antibiotic-resistant bacteria have survived, resulting in
more offspring with this trait.
D. The bacteria have become genetically isolated, resulting in
decreased reproductive rates.