Bio 230 Exam Two
Sugar-Phosphate Backbone
"Handrail" of the DNA structure.
DNA Adduct
"Sticker" that binds to DNA nucleotide that leads to a mutation. Changes the nucleotide sequence.
HeLa Cells
'Immortal cells' Double every 24 hours First to live outside the human body and sold
What is the chance of getting cherries in the first five slots of this same machine?
(¼)^5
If a woman has a new mutation in the p53 gene in a skin stem cell, what is the chance that she will pass that mutation on to her offspring (children)?
0% because it won't move to the gametes
Erwin Chargaff
Came up with the idea that A-G and C-T are equal and DNA chemical structure of base pairs
Lynn Margulis
Came up with theory for endosymbiosis Evolution of prokaryotes to eukaryotes.
Stem cells
Can differentiate into specialized cells. Can divide via mitosis to produce more stem cells
Malignant
Cancer/tumor that can spread and grow
Mutagen
Causing agent of mutations such as chemicals, sunlight, viruses, radiation etc.
Which cells in your body are capable of dividing by meiosis?
Cells that are capable of dividing by meiosis.
Specialized cells
Cells that perform a certain function Do not divide
Protein production
Central Dogma (DNA -> RNA -> Protein)
Missense Mutation
Change in a neocleotype that results in a new nucleic acid
Trait
Characteristics that are inherited, determined by the presence or absence of a protein
What are examples of mutagens in the environment that can cause DNA mutations?
Chemicals, cigarettes, uv radiation, radiation, chemicals, viruses, prions, types of bacteria, acne treatments
Homologous Pairs
Chromosome pairs from each parent. Have the same genes but with different alleles.
Plasmid
Circular DNA that is able to replicate independently. Mostly found in bacteria.
Carol Greider
Co-discovered telomerase, a key enzyme in cancer and anemia research, along with Blackburn.
James Watson
Co-discovery of DNA's double helix structure with Francis Crick
Non-coding DNA
Components of an organism's DNA that do not encode protein sequences.
Haploid
Containing one set of chromosome
Diploid
Containing two sets of chromosome
Mitosis
Copy machine produces a copy of itself
Cytosine
Cytosine is a pyrimidine base (C4H5N3O) that codes genetic information in the polynucleotide chain of DNA or RNA
DNA
Deoxyribonucleic acid is a thread-like chain of nucleotides carrying the genetic instructions used in the growth, development, functioning and reproduction of all known living organisms and many viruses.
Y chromosome
Determines the male sex Inherited from the father.
Punnett square
Diagram use to predict outcome of offspring.
What is cell with one pair of homologous chromosomes?
Diploid
Zygote
Diploid cell resulting from fertilizing two haploid gametes; fertilized egg.
Stan Prusiner
Discovered Prions
Elizabeth Blackburn
Discovered the study of telomeres and the co-discovery of telomerase, an enzyme that controls telomeres.
Are dividing or non-dividing cells more likely to acquire mutations?
Dividing cells are more likely to gain mutations. More chances for errors in DNA replication.
Cell division
Division of a cell into two daughter cells with the same genetic material.
What are dominant and recessive alleles?
Dominant alleles are the alleles that appear in offspring and recessive alleles are masked in the presence of a dominant allele.
In what parts of the cell cycle do mutations happen?
During the S phase of the cell cycle (replication) into sister chromatids
Structure
Dynamics of biological macromolecules
If someone said to you that cancer is disease of stem cells, would you agree with them? Why or why not?
I would clarify, "Cancer is a disease that can occur in stem cells as well as the rest of the cells in your body."
Polypeptide
Multiple monomer's of saccaride chains
How many chromosomes are present before and after a complete round of meiosis?
23 chromosomes
What is Aspergillus flavus?
2nd or 3rd most common cause of invasive disease, aflatoxin production, allergic reactions
How do cells replicate their DNA? In which direction is the newly synthesized strand produced?
5' end to the 3' end going towards each other.
If a woman has an inherited mutation in the p53 gene, what is the chance that she will pass that mutation on to her offspring (children)?
50%
Telomerase
An enzyme that is made of protein and RNA subunits, that extends chromosome's sequences (and their telomeres). If telomerase is activated in a cell, the cell will continue to grow and divide.
How would you explain all the parts of a Punnett Square?
A box divided into four with Mother alleles on one outside and father's on the other. They combine in each subdivision creating four new allele outcomes.
Telomeres
A cap that is located at the ends of the chromosome. Stops DNA repairing and replication on the chromosome. (Aging cells that die)
Chromosome
A chromosome is a strand of DNA that is encoded with genes. In most cells, humans have 22 pairs of these chromosomes plus the two sex chromosomes (XX in females and XY in males) for a total of 46
Codon
A codon is a sequence of three DNA or RNA nucleotides (A,C,G,T/U) that corresponds with a specific amino acid or stop signal during protein synthesis
What is a diploid cell?
A diploid cell contains two sets of chromosomes, one from each parent.
What is Aspergillus flavis?
A fungus that makes aflatoxin.
Recessive
A genetic trait that results from the expression of the two recessive alleles.
Genome
A genome is an organism's complete set of DNA, including all of its genes
What is a haploid cell?
A haploid cell contains one set of chromosomes in your gametes.
Proteins
A molecule composed of polymers of amino acids joined together by peptide bonds.
Phospholipids
A phospholipid is a type of lipid molecule that is the main component of the cell membrane (phospholipid-bilayer)
Gene
A portion of a DNA molecule that serves as the basic unit of heredity. Genes control the characteristics that an offspring will receive from their parent
Transgene
A segment of DNA from one organism introduced into the genome of another organism
Monosaccharide
A simple sugar. The simplest form of carbohydrate; therefore, it cannot be broken down to simpler sugars by hydrolysis.
Prion
A small proteinaceous infectious disease-causing agent that is believed to be the smallest infectious particle
Point Mutation
A small-scale mutation characterized by a change of only one nucleotide base in the DNA or RNA molecule
What is aflatoxin?
A toxin that attaches itself to guanine (G) in DNA and results in a miscoding.
Loss-of function
A type of mutation in which the altered gene product lacks the molecular function
Gain-of-function mutation
A type of mutation in which the altered gene product possesses a new molecular function
Virus
A virus is an infectious particle that reproduces by "commandeering" a host cell and using its machinery to make more viruses. A virus is made up of a DNA or RNA genome inside a protein shell called a capsid.
What is a Punnett Square?
A way to predict possible genotypes from parent to offspring.
Autosome
Any chromosome not considered as a sex chromosome
Random fertilization
Any egg can fertilize any sperm. Promote genetic diversity
Eukaryote
Any of the single-celled or multicellular organisms whose cell contains a distinct, membrane-bound nucleus.
Nucleic Acids
Any of various complex organic acids (such as DNA or RNA) that are composed of nucleotide chains
Silent Mutation
Base substitutions that result in no change of the amino acid or amino acid functionality when the altered messenger RNA (mRNA) is translated
Hydrogen Bonds
Bond between an H and O,F,N Weak bond of attraction
Ionic Bonds
Bond that gives electrons
Covalent Bonds
Bond that shares electrons
Starch
Broken down into glucose by the body as energy fuel and storage
Monomer
Building blocks to make a long-chain molecule for polymers
If you know the genotype of the parents, how would you go about predicting the genotype and phenotype of all possible offspring?
By plugging in the parent's genotypes to a punnett square we can know the possible outcomes for their child.
How can we use our knowledge of genetics to predict genotypes and phenotypes?
With the knowledge of dominant and recessive alleles we can predict the possible genotypes and phenotypes of a parents offspring.
Chloroplast
Work to convert light energy of the Sun into sugars that can be used by cells.
Would the cells you drew after meiosis look any different from the original cell? Why, or why not?
Yes, because they have half the genetic information as the parent cell.
Genomes
complete set of genetic material in an organism
Substitution Mutation
Mutation that exchanges one base for another could result in a change of codon to one that encodes a different amino acid and cause a small change in the protein produced.
How do acquired mutations arise?
Mutation that occurs after someone was born Mutation that occurs during a person's lifetime, either spontaneously or from environmental factors; examples: radiation, smoking, toxins
Acquired mutation
Mutations acquired from environment such as diet, radiation, chemicals etc; acquired mutation in somatic cells do NOT get passed on
Would the cells you drew after mitosis look any different from the original cell? Why, or why not?
No, because it's replication and division once in the cell division process. 2N ploidy level to 2N ploidy level
Are all mutations caused by mutagens?
No, mutations can also be caused by errors in DNA replication, repair, and replication
Benign
Non-cancerous tumor
Intron
Non-coding, intervening sequence of DNA
Tumor Suppressor Genes
Normal genes that slow down cell division, repair DNA mistakes, or tell cells when to die
Uracil
Nucleotide base for DNA
Thymine
Nucleotide base of DNA
Adenine
Nucleotide in DNA
Mutations
Occurs when a DNA gene is damaged or changed in such a way as to alter the genetic message carried by that gene.
What is a cell with one pair of homologous chromosomes?
One set of homologous chromosomes
Genetically Modified Organism
Organism whose genetic material has been altered using techniques in genetics
What is p53?
P53 is a tumor suppressor protein that binds to the DNA and is essential in regulating the cell cycle. It is activated when the cell is damaged or is under stress "Guardian of the Genome"
To what extent do you agree or disagree with the statement: "Peanuts can cause cancer"?
Peanut butter can cause cancer if it is affected by Aspergillus fungus which produces aflatoxin.
Why is aflatoxin exposure relatively low in the US?
Peanuts are thoroughly cleaned in the factory.
Heterozygote
Person with 2 different alleles of a gene
Maurice Wilkins
Photographs of X-ray studies of DNA (that allowed Watson & Crick to discover DNA double helix structure.)
Phenotype
Physical trait that we expressed
Nucleus
Powerhouse of the cell
Pre-mRNA
Primary transcript of eukaryotic mRNA as it comes off the DNA template still containing introns
DNA replication
Process of creating two identical replicas of DNA via DNA polymerase. Occurs in S phase of cell cycle.
Transcription
Process of encoding DNA into RNA via RNA polymerase. Occurs in nucleus of the cell.
Translation
Process of encoding mRNA to amino acids to make proteins. Occurs in the ribosomes in the cytoplasm.
Differentiated cells
Process where a cell changes from one cell type to another. Occurs numerous times during the development of a multicellular organism as it changes from a simple zygote to a complex system of tissues and cell types
APC gene
Produces the APC protein which is a tumor suppressor. A mutation in this gene will lead to uncontrollable cell division Can lead to colon cancer.
mRNA
Product of the removal of introns from Pre-mRNA
Bacteria
Prokaryote that can be found everywhere and can be harmful to the body
Prokaryotes
Prokaryotes are unicellular organisms that consist of a single prokaryotic cell with no nucleus.
Exon
Protein-coding region in the DNA
Amino Acid
Proteins and the building blocks of the natural world. Polypeptide chains
How would you determine the probability of obtaining certain genotypes and phenotypes?
Punnett square.
RNA
RNA contains protein information that has been copied from DNA and brings it to different cells
Mutations
Random errors in gene that lead to a change in the sequence of nucleotide
What is random fertilization?
Random fertilization means that the collection of genes within one gamete (such as a sperm cell) do not give that gamete a lesser or better chance than any of the other sperm cells of fusing with an egg cell to produce a zygote.
What is the chance of getting a cherry in the first slot of a slot machine that has four possible fruits?
¼
What's the chance that a couple's second offspring would possess the same DNA as the previous child?
½^46
Assuming no meiotic crossover and no new mutations, what is the probability that an organism with 6 pairs of chromosomes would be genetically identical to a sibling born at a different time?
½^6
How likely is it that the kids of 2 pairs of identical twins would also be identical?
½^92
Loss-of-function mutation
Result in the gene product having less or no function
Nonsense Mutation
Results in a shorter, unfinished protein product Stop codons are also called nonsense codons
Ribosome
Ribosomes are a cell structure that makes protein in the cytoplasm
What is a cell after DNA duplication of that one pair of homologous chromosomes, but twice the DNA and sister chromatids?
S phase
Colon cancer
Second most common cause of cancer related death 90% of cases are people over 50 Two types: Familial Adenomatous Polyposis & Hereditary Non-polyposis Colorectal Cancer
Sex chromosome
The two chromosomes in each cell of a living thing that determine what sex it is
Endosymbiosis
Theory that eukaryotes came from prokaryotes
What makes an allele 'recessive' or 'dominant'?
There are two alleles and only one can win. That's the dominant.
How are mutations inherited?
There is an error mutation in the gametes before fertilization or after the egg is fertilized during mitosis.
What are the roles of newly-acquired mutations and inherited mutations in tumor progression?
They affect tumor suppressors so the cells begin to divide uncontrollably.
Chromosomes
Threadlike structures made of DNA molecules that contain the genes
Which cells must carry a mutation in order for it to be passed on to offspring?
Gametes
Central Dogma
Gene expression (transcription/translation) DNA-->RNA-->Protein-->trait
Proto-oncogenes
Genes code for proteins that help regulate cell growth. Can transform into a cancer cell
Genotype
Genetic makeup of an organism
How do genotype and phenotype relate to DNA and proteins?
Genotype are like DNA and phenotypes are like proteins.
Heterozygous
Genotype containing 2 different alleles of a gene, the dominant and recessive
Homozygote
Genotype containing identical alleles
Henrietta Lacks
Had cancer Cells were stolen Cancer killed her in 6 months Family did not know her cells were being used until years after
Sister-chromatids
Half of a duplicated chromosome. Identical copies of a chromosome connected by a centromere.
Ignoring crossing-over, the four cells produced after the second cell division in meiosis? Haploid daughter cells ready to combine with other
Haploid daughter cells ready to combine with other
Homozygous
Having identical pairs of genes
Sickle Cell Disease
Hereditary disease. blood disorder caused by a point mutation in the allele coding for the beta chain of hemoglobin
Model Building
How Watson and Crick helped discover the shape of DNA
Cell cycle
Interphase: consists of G1,S,G2. The cell is growing and replicating DNA. Mitosis and cytokinesis is where cell is dividing.
What is a DNA adduct?
Is a segment of DNA bound to a cancer-causing chemical. This process could be the start of a cancerous cell.
How does aflatoxin affect the protein coded for by the p53 gene?
It changes the G to a T when DNA coded.
What is the role of p53 mutations in liver cancer?
It results in the cells to divide uncontrollably.
Nitrogenous bases
A,U,G,T,C the building blocks of nucleic acids
Cancer
Abnormal cell division without control and can invade nearby tissues
Tumor
Abnormal mass of tissue Can be benign or malignant.
Polyp
Abnormal tissue growth on mucous membrane. Mostly benign and non cancerous but can increase chance of cancer
If there is an aflatoxin adduct in a single cell that then divides two times to produce four cells, how many of the cells produced will have an adduct?
Adduct is attached to single cell which contains double stranded DNA, the adduct or chemical changes how the single stranded DNA gets replicated. After a second division there would be 2 mutated cells with 1 adduct
How does a DNA adduct lead to a mutation?
Adducts change the DNA structure, affecting the ability of DNA-polymerase to translate the DNA.
What is aflatoxin?
Aflatoxin is present in moldy food such as grains and peanuts It has been associated with liver cancer
Cell Theory
All living things are made up of one or more cells. The cell is the structural and functional unit of all living things. Cells come from pre-existing cells through the process of division. All cells are the same in regard to chemical composition.
Base Pairing Rule
Amount of (G)uanine should be equaled to (C)ytocine and the amount of (A)denine should be equaled to (T)hymine. G-C , A-T. EXAMPLE: If G has 20%, C also has 20%
Chargaff's Rule
DNA from any cell of all organisms should have a 1:1 ratio (Base Pair Rule).
DNA Cloning
DNA polymerase creates the copy of the original DNA strand. Protein production = Central Dogma (DNA -> RNA -> Protein)
What are the differences and similarities between DNA replication and Central Dogma (transcription and translation)?
DNA replication and Central Dogma both involve copying DNA. DNA replication makes a copy of DNA and the Central Dogma copies DNA to make RNA.
What is a cell after DNA duplication of that one pair of homologous chromosomes, but twice the DNA and sister chromatids? (mitosis)
DNA replication doubles genetic info creating sister chromatids
What causes cancer?
Damage to genes the encode growth factors Mutation: caused damages to the genes Result of chemical, environmental or viral exposure
Mad Cow Disease
Degenerative disease in a cow's brain and spinal cord
Does the type of fruit in the first slot affect which fruits will show up in the other slots?
Each possibility is independent from each other.
DNA polymerase
Enzyme that replicates DNA
Somatic cells
Every cell in the body besides the gametes Have a full set a chromosomes Replicate through mitosis
Cell Membrane
Fatty biological membrane that separates the interior of all cells from the outside environment
Lipids
Fatty compound involved energy storage and the structural component of cell membrane
Ignoring crossing-over, the two cells produced after the first cell division in meiosis?
First division Diploid cells
If there is an aflatoxin adduct in a single cell that then divides seven times, how many cells total will be produced?
For mitosis, there are 2 cells produced at the end of each cycle. So, 2 daughter cells ^ 7 divisions = 128 cells.
Independent assortment
Formation of random combinations of chromosomes in meiosis and of genes on different pairs of homologous chromosomes, which are not dependent on each other
Aflatoxin
Formed through the FUNGI, Aspergillus flavus. They are in peanuts and formed under a warm, humid, hot environment.
Function
Function pertains to the reason in which an object or a process occurs in a system
Aspergillus
Fungus that can grow on nuts and corn in hot, humid weather.
How are these ideas used to help us understand and predict likely offspring (children) and their traits?
If one has an understanding of their own genes and alleles we can know what alleles could be potentially passed onto our children.
How might peanut cultivation for food be connected to liver cancer in Africa?
If peanuts are left out they can get Aspergillus fungus which causes liver cancer.
Dominant
If the dominant allele is present the dominant trait will always appear over the recessive
Cellulose
In plant cell walls Made chains of glucose monomers
What is the law of independent assortment, and how does it relate to how gametes are formed?
Independent assortment is when the maternal and paternal chromosomes move over during metaphase which mixes up the parents information.
X chromosome
Inherited from mother
How would you explain this difference between sporadic (new) and inherited mutations?
Inherited mutations rely on chance whether they are inherited or not while sporadic mutations are caused by a force.
Frameshift Mutation
Insertion or deletion of a nucleotide that causes the sequence to shift, changing the resulting protein.
If you know the phenotype of the offspring, how do you go about predicting the phenotype/genotype of the parents?
Knowing the phenotype tells you something about the alleles passed on by their parents.
Mitochondrion
Known as the powerhouses of the cell Performs cellular respiration
Rosalind Franklin
Known for her role in the discovery of the structure of DNA, and for her pioneering use of X-ray diffraction.
Polymer
Large molecule, or macromolecule, composed of many repeated subunits.
Proteins
Large molecules composed of one or more long chains of amino acids and are an essential part of all living organisms
Metastasis
Medical term for cancer that spreads to a different part of the body from where it started.
In what ways is meiosis like a slot machine?
Meiosis is like a slot machine because you always get different chromosomes.
In what ways are mitosis and meiosis similar?
Mitosis and Meiosis are similar because they both go through the first stages of mitosis and DNA replication occurs in both of them.
In what ways are mitosis and meiosis different?
Mitosis makes a copy of DNA for a cell and meiosis mixes two parents' genetic information.
M phase of cell cycle
Mitosis, where cell nucleus divides into two identical daughter cells.
Sucrose
Most common type of sugar and is made of monosaccharide chains of glucose and fructose
Genes
Sequence of DNA that codes for a protein and thus determines a trait
Germ line cells
Sequence of cells which develop into eggs and sperm
Nucleotides
Sequence of nucleotides in the DNA or RNA codes for the structure of proteins synthesized in the cell.
Gametes
Sex cells Contain half the number of chromosomes Produced through meiosis
Gametes
Sex cells Go through meiosis Only mutations in gametes can be passed on
Promoter
Site on DNA to which the enzyme RNA polymerase can bind to initiate the transcription of DNA into RNA
Ribosomes
Site where translation occurs RNA is coded into amino acids to make proteins Located in cytoplasm
Double Helix
Structure of DNA Sugar-phosphate backbone and nucleotide bases. Twisted in a ladder-like pattern
Carbohydrates
Sugars, starches, and celluloses
RNA Polymerase
Synthesizes (produce) RNA by following a strand of DNA
Are the cells before and after mitosis diploid or haploid?
The cells before mitosis are diploid and after are diploid.
Alleles
The different forms of a gene
What is the relationship between dominant/recessive alleles and gain-of-function/loss-of-function mutations?
The dominant gene is usually the gain-of-function and the recessive gene is usually the loss-of-function.
Dictionary of Genetic Code
The genetic code is based on an "alphabet" consisting of sixty-four triplets of nucleotides called codons. The four nucleotides that bond in a specific order are: Adenine, Cytosine, Guanine, and Thymine/Uracil.
What is the law of segregation, and how does it relate to how gametes are formed?
The law of segregation is when the maternal and paternal genetic information separate and end up in different gamete cells.
Nuclear Membrane
The lipid bilayer membrane which surrounds the genetic material and nucleolus in eukaryotic cells.
Meiosis
The part of gamete formation where DNA is doubled, then divided twice Slot machine; independent assortment
How is genotype manifested as phenotype?
The phenotype is the physical manifestation of an organism's genotypes.
How are traits (including predisposition to cancer) inherited?
Traits are inherited by your parents gametes.
Monogenic trait
Traits produced by a single gene/alleles
Polygenic trait
Traits produced by multiple genes/ alleles
p53
Tumor suppressor gene
What are the two cells produced after cell division in mitosis?
Two Diploid cells
U ABC IT
Use evidence Ask questions Be skeptical Cultivate wonder Identify confusions Think like a biologist
Glucose
Used for energy and fuel. Made of C6H12O6 (Carbon, hydrogen, oxygen atoms)
X-Ray Crystallography
Used to find the shape of DNA by Rosaline Franklin
Francis Crick
Using X-ray diffraction studies of DNA Constructed a molecular model of DNA, known as double helix.
Gregor Mendel
Usually considered to be the founder of modern genetics. Though farmers had known for centuries that crossbreeding of animals and plants could favor certain desirable traits
Law of segregation
When sperm and egg unite at fertilization, each contributes its allele, restoring the paired condition in the offspring.
Where in the body are inherited mutations found?
You can determine what caused the mutation by looking at the cells in which the mutation is found. Inherited mutations are found in all cells, and can be passed on (since found in gametes). Acquired mutations occur at the site of mutation. Newly acquired cancers that aren't in the gametes (like skin cancer) won't be passed on to kids.
How does this relate to independent assortment during meiosis?
You receive 23 slots called chromosomes from each parent totally 46 with two allele options for each chromosome.
S phase of cell cycle
part of interphase where DNA replication occurs
