Sickle Cell Disease Study Guide

Put the steps of translation in order as they happen; be sure to include RNA types, enzymes, organelles, and products.

1 Denaturation (95°C) enzyme dna replication 2 Annealing 50°C primer binds 3 Extension (72°C) makes double Dna strand

Explain the basic steps of genome editing.

1. generate CRISPRs made in the lab and CRISPRS are guide molecules 2.use cloning in bacteria or PCR to make normal genes. 3.. Add normal DNA pieces to cells along with CRISPR guides and Cas9 enzymes

If a DNA sequence is 16% guanine what percentage of the strand is adenine?

16% Thymine

Create a timeline that briefly outlines the key work on the path to describing the structure of the DNA molecule.

1940 Erwin Chargaff, identified the pattern of nucleotide base-pairing. 1950 james watson and francis crick build double helix structure. 1962 James watson and francis crick won nobel prize.

Explain the structure of hemoglobin.

A complex protein that consists of four polypeptide chains, called globins (two alpha and two beta globin genes), four heme groups (gives blood its red color), and four iron atoms.

Explain the purpose of meiosis.

A form of cell division that reduces the chromosome number by half and introduces variation into the daughter cells. The purpose of meiosis is to make an organism's offspring.

Define what a genetic disease is.

A genetic disease is caused by a mutation in the genetic information of an individual that can be passed from one generation to the next.

Know what a karyotype is and the basic concept behind FISH.

A karyotype is a laboratory-produced image of someone's chromosomes. Fluorescent In Situ Hybridization (FISH) takes short strands of lab-generated DNA and mixes them with chromosomes. The lab DNA binds with complementary DNA on chromosomes and antibodies with fluorescing molecules bind to the tags. This gives a karyotype that can easily allow detection of chromosomal abnormalities.

What are the genetic and physical characteristics of sickle-cell disease?

A single change or mutation in a gene causes sickle cell disease also referred to as sickle-cell anemia. The physical characteristics are a sickle-shape.

Explain how complementary base-pairing binds the DNA strands together.

Adenine and thymine bond

Explain: how are a person's alleles related to their physical appearance?

Alleles are different variations in a gene, which some genes affect a person's physical appearance, therefore making alleles important to different physical appearances.

Dominant

An allele or trait that masks the expression of another allele.

Recessive

An allele or trait whose expression is masked by a dominant allele.

Gene

Basic unit of inheritance

Explain four common uses of transgenic bacteria.

Biotechnology products: proteins and enzymes used as drugs or part of drug production. Insulin, hepatitis B vaccine, clotting proteins, etc. Biofuels: the conversion of biomass into liquid fuels, ethanol or biodiesel. Bioremediation: bacterial enzymes break down toxic chemicals, such as petroleum oil spills or mercury. To enhance crops: Bacterial cryoprotectants, chemicals that prevent freezing Bt, Bacillus thuringiensis, produces toxins that repel insects but are not toxic to humans.

Outline the pros and cons of the techniques used to extract DNA for testing.

Blood test: Hair: Amniocentesis: Explained above. Chorionic villus sampling: can be done at an earlier stage than Amniocentesis, but has the same possible side effects and can cause limb defects if done improperly. Circulating fetal cells: Non-invasive and can happen in a relatively sooner window, but will need further testing if abnormalities are seen as this method is not yet FDA approved.

Explain the two main methods to obtain cells from adults.

Blood test: specifically, the white blood cells. Hair: must contain the root as the shaft of the hair does not contain live cell

Describe how genome editing could be used to treat genetic diseases.

CRISPR targets certain cells can be used on incorrect cells close to a bounty board

Define gene editing.

Changing dna and is larger scale

Summarize the effects of sickle-cell anemia on the body.

Chronic and acute complications such as nerve organs, bones, ETC.

Define cloning and briefly explain the steps involved in the process of inserting a gene.

Cloning is copying biological material, either the whole organism or a piece (DNA). Step 1: Insert DNA/gene into a bacterial plasmid, creating a transgenic plasmid with recombinant DNA. Recombinant DNA: Has a gene from another organism. Transgenic: A organism with recombinant DNA. Step 2: Bacteria reproduce, many copies of the recombinant DNA form in the plasmid. Step 3: Gene expression in this transgenic bacteria will create the protein coded by the recombinant piece. Step 4: DNA sequencing then occurs.

What are the general patterns of inheritance? Can you determine the genotype of an individual that expresses a recessive trait?

Construct or analyze a pedigree to determine the inheritance pattern of a trait - recessive or dominant. Dominant genes are usually passed down to each generation, while recessive genes can skip generations before coming up again. Show incomplete dominance patterns.

Explain how gene therapy is being developed for sickle cells.

Correcting red bloods cells outside of the body and inputting correct ones into bone marrow

What is meant by the term semiconservative?

DNA contains one original and new strand.

Define the common abnormalities observed.

Deletions: portion(s) of a chromosome is lost. Results in Cri du chat, Prader-Willi syndrome, Williams syndrome, etc. Translocation: part of one chromosome accidentally crosses-over with a non-homologous chromosome. Causes several types of cancers. Duplications: a complete or partial duplication of a chromosome. Causes down syndrome (trisomy 21), Edward syndrome (trisomy 18), and Patau syndrome (trisomy 13).

Sex Chromosomes

Different in male and female. XX = female, XY = male.

Explain the difference between diploid (2n) and haploid (1n).

Diploid organisms have two copies of each chromosome, Haploid only have one copy of each chromosome.

Summarize the process of gene expression. Compare and contrast DNA to RNA.

Dna has instructions, Rna regulate proteins

Explain why DNA must be able to be copied (replicated).

Due to PCR

Explain how hemoglobin is able to carry and exchange gasses throughout the body.

Due to hemoglobin having four iron molecules, it can hold four oxygen molecules which then get exchanged during the circulatory system.

Compare the techniques of ex vivo and in vivo therapy.

Ex vivo is outside of the body and in vivo occurs on the inside

Explain why gametes contain half (n) the number of chromosomes as body cells.

Gametes contain half of the genetic material because when they combine, they will make a full chromosome set for the parent's offspring.

Explain: how are genes and chromosomes involved in inheritance?

Genes and chromosomes are involved in inheritance because we take half of the genes on the chromosomes of each of our parents to make full chromosomes for us.

Describe the function of a gene.

Genes are segments of DNA that contain instructions for the production of a protein.

How are genetic diseases different from communicable diseases like the flu?

Genetic diseases can be passed down through generations.

Heterozygous

Having different copies of alleles in an individual.

Homozygous

Having two copies of the same allele.

Be able to label the four bases, sugar, phosphate, and types of bonds found between each DNA molecule.

Hygrdeon bonds. 4 bases are A.C.G.U. Sugar=

Explain the future of genome editing and sickle-cell disease.

Ideal for gene editing due to a single mutation, additional work is happening, and use of crispers=40% repair on progenitor cells.

Generation

Identifies the number of generations following the parental (P) generation.

Explain how sickle-cell RBCs affect the spleen and gallbladder.

In SCD, red blood cells get trapped in the spleen, causing the spleen to grow which can be very painful. In SCD, the breakdown of hemoglobin increases the concentration of bilirubin in the gallbladder forming gallstones.

Trace the path of red blood cells in the body. Relate how gasses are exchanged in the circulatory system.

In the circulatory system, oxygen within the alveoli can diffuse into red blood cells. The red blood cells then go throughout the body then return to the circulatory system to get a refill on oxygen.

Explain the type of information that is stored in genes.

Instructions for the production of protein.

What organelle is responsible for making proteins?

Instructions within DNA found in genetic material

Relate how a change in the DNA code can result in a misshapen or malfunctioning protein.

It has instructions to make bad proteins instead of creating normal ones.

Identify the two challenges of gene expression and which steps in the process overcome these challenges.

Location and Language overcomes with translation

Explain what the different symbols on a pedigree mean.

Males = Square Females = Circle Shaded Circle or square = affect with trait of interest Line across square or circle = deceased Line between square and circle = union (ex: marriage) Vertical lines = inheritance Triangle = Miscarriage Circle or square with brackets = adopted

Explain the process of meiosis and major events that occur during meiosis I.

Meiosis follows the same series of steps as mitosis but goes through two rounds. The major events of meiosis I are: Prophase I: Crossing-over of chromosomes; Recombines the genetic information from the two homologous chromosomes, and produces new combinations of alleles not present in their original chromosomes. Metaphase I: Similar to mitosis, however, instead of all the chromosomes creating one vertical row, with chromosomes on top of each other, in metaphase I of meiosis homologous chromosomes pair next to each other. Anaphase I: Instead of sister chromatids pulling apart (like in mitosis), homologous chromosomes are pulled to opposite sides of the cell. Telophase I and all of Meiosis II are uneventful and similar to mitosis.

Briefly explain Mendel's experiment.

Mendel took a homozygous plant for green pea pods (GG) and crossed it with a homozygous plant for yellow pea pods (gg). The first generation (F1) produced plants with all green pea pods. However, when plants from the F1 generation were crossed with each other, the resulting F2 generation had a phenotypic ratio of 3 green plants to 1 yellow plant.

Circulating fetal cells

Non-invasive, performed during 10-22 weeks of pregnancy, blood is drawn from mother and the presence of genetic abnormalities often result in a follow-up using one of the two previously mentioned techniques.

Why don't all DNA mutations result in misshapen proteins?

Not all mutations change the shape of a cell.

Be able to explain how a person with AB blood type can't have a child with O blood type.

People with AB blood type don't have the i gene required to make a child with O-blood type.

Be able to explain Griffiths's experiment and what the conclusion of the experiment was.

Pneumonia bacteria and what was the factor for transformation. Conclusion R strain = live, S strain = Dead, heat killed s strain= live, heat killed s strain and live r strain = dead,

Explain the relationship between proteins, amino acids, and DNA.

Proteins are a combo of 20 different amino acids. Within dna it contains instructions to make proteins

Distinguish between recessive and dominant forms of inheritance.

Recessive: must have two of the allele to show genotype, the allele can be passed on through generation but be hidden. Dominant: Dominates recessive genes, passes through each generation.

Explain why red blood cells cannot be used for genetic testing.

Red blood cells do not have nuclei and therefore do not contain DNA, which means they can't be used for testing.

Explain how CRISPR has the potential to treat genetic diseases.

Replacing mutated cell genes

What is gene expression?

Takes info from DNA and turns it into RNA

Relate the structure of sickle cells to respiratory distress.

The blockage causes a condition known as acute chest syndrome. Characterized by pain and shortness of breath, and is often accompanied by a high fever.

Genotype

The combination of alleles in an individual.

Explain how the daughter cells are different from the starting parent cell.

The daughter cells have half of one cell's DNA and half of another cell's DNA, making the daughter cell genetically different from the starting parent cell(s).

Explain what causes the sickling of red blood cells in sickle-cell disease.

The mutation causes the shape of the beta globin protein to become misshapen causing the hemoglobin to clump and form long needle-like fibers.

Phenotype

The physical characteristics of the trait.

Explain how the shape of the sickle-cell RBCs causes problems within the circulatory system.

The shape of the sickle-cell RBC causes problems by blocking the capillary and restricting blood flow to the organs and tissues.

Formulate a definition and example of biological inheritance.

To be inheritable, a trait must be encoded in the genes of our DNA, and a copy of these genes must be able to be passed onto the next generation of individuals. An example of this for humans is sexual reproduction and the production of gametes.

Be able to explain the results of the Hershey-Chase experiment.

To prove DNA was heredity by tracking radioactive

Explain the goal of gene therapy.

To provide the cells correct copy of gene

Explain the function of hemoglobin in the circulatory system.

Transport O2

Determine the inheritance pattern of sickle-cell disease.

Two copies of the recessive allele that causes sickle-cell disease must be present for sickle-cell disease to occur. This means that sickle-cell disease is a recessive genetic disease, and while someone might not have sickle cell disease they can have offspring that does if they and their partner both have one of the alleles.

Explain what contributions Watson, Crick, and Franklin made to DNA structure.

Watson and Crick= yoinked franklin's work Franklin= X ray to see dna structure

Be able to explain Avery, Macleod, and McCarty's experiment. Why it was performed and what the conclusion of the experiment was.

Why to determine what was the killing factor. Conclusion nucleic acid dna; Dnases: phosphates, esterases, delpoyfoses.

Chorionic villus sampling

a suction tube is used to extract cells from the chorion, where the placenta will develop.

Allele

a variation of a gene, usually due to small changes in the nucleotide sequence within the gene.

Explain the components of the CRISPR-Cas9 system.

bacterial immune response to virus

Describe the relationship between mRNA, tRNA, and amino acids.

mRNA and tRNA= second anticodon and codon ribosome.amino acids= at the end of opposite side of tMRA

autosomes

the first 22 pairs of chromosomes, no differences between them in males and females.

Identify the key components involved in DNA replication.

the helicase enzyme breaks the hydrogen bonds, DNA polymerase enzyme begins to synthesize new strands of DNA, leading strand follows helicase enzyme, lagging strand makes short dna segments

Amniocentesis

uses a long needle to withdraw amniotic fluid, containing fetal cells. Requires a large amount, around 20ml (1/10 of the amniotic fluid), requiring the fetus to be 15 weeks old (3.5 months). Can cause 1/200 women to have a miscarriage and has a potential for infection.

Explain: how are vectors used in gene therapy?

virus vectors to deliver normal DNA to cells which are then place into a body with defective DNA