Test #1 Introduction and Mendelian Inheritance Flashcards
What is the Human Genome Project?
The Human Genome Project (HGP) was an international scientific research project that aimed to map and understand all the genes of the human species. It was initiated in 1990 and completed in 2003, involving collaboration among scientists from various countries. The primary goals of the Human Genome Project were to identify and map all the genes in human DNA, determine the sequences of the chemical base pairs that make up human DNA, store this information in databases, and develop tools for analyzing and interpreting the data.
How many nucleotides does the human genome have?
3.2 billion.
How many genes do we have?
There are 23,000 genes.
What is the fundamental unit of heredity that carries information for the development, functioning, and characteristics of living organisms, and is passed from one generation to the next through reproduction?
Genes.
What is the study of heredity?
Genetics
What does each cell contain?
Each cell contains 46 chromosomes into 23 pairs, 2 meters of DNA, approximately 3 billion DNA base pairs, and bases of A,T,C, and G.
What are some uses of gene cloning?
Insulin, growth hormones, vaccine production, gene therapy, cotton, soybean, and canola.
What is the first mammal to be cloned?
The first animal to be cloned is a sheep called Dolly in 1997.
What is gene cloning?
Cloning is a process that creates genetically identical copies of an organism or a group of cells.
What are stem cells?
Stem cells are undefined cells that reproduce continuously and can develop any type of cells or tissues.
Where are stem cells more easily obtained from?
Embryos and umbilical cords.
Where are adult stem cells found?
Adult stem cells are found in the bone marrow and skin.
What’s the Griffith Experiment?
Griffith sought to investigate whether the virulence of the bacteria was due to a heritable genetic trait. To do this, he conducted a series of experiments using mice and two strains of S. pneumoniae: a virulent strain (smooth colonies) and a non-virulent strain (rough colonies).
Experiment 1 - Live Virulent and Dead Non-Virulent Bacteria: Griffith injected mice with live virulent bacteria, which resulted in their death from pneumonia. He then injected mice with dead non-virulent bacteria, which did not cause pneumonia, and the mice survived.
Experiment 2 - Heat-Killed Virulent Bacteria and Live Non-Virulent Bacteria: In this experiment, Griffith heat-killed the virulent bacteria to render them non-viable and injected them into mice. Surprisingly, the mice injected with the heat-killed virulent bacteria did not develop pneumonia and survived.
Experiment 3 - Mixture of Heat-Killed Virulent and Live Non-Virulent Bacteria: Griffith then combined heat-killed virulent bacteria with live non-virulent bacteria and injected them into mice. Strikingly, the mice developed pneumonia and died, showing symptoms similar to those caused by the virulent strain.
Conclusion: Griffith concluded that something in the heat-killed virulent bacteria had transformed the live non-virulent bacteria into a virulent form. He termed this phenomenon “transformation” and suggested that the genetic material from the dead virulent bacteria was somehow taken up by the live non-virulent bacteria, allowing them to acquire the ability to cause disease.
Was it proteins, carbohydrates, lipids, nucleic acids or proteins found to be the cause within the R strain?
Nucleic acids.
What is the Hershey and Chase Experiment?
The Hershey and Chase experiment was conducted to prove if genes were made of proteins or DNA. In this experiment, two types of genetic material were tested. The S35 containing radioactive sulfur and P32 containing radioactive phosphorus. The proteins allowed for the phages to infect the bacteria. After infection, the empty phage protein coats were removed by agitating cells in a blender. The cells were recovered by centifruge.
The results of this study shows that most of 32P remained with the bacterial cells but S35 was found in the surrounding medium. This proved that DNA was the genetic material of bacteriophages.
Who found that DNA is a long, thin, helical molecule?
Rosalind Franklin used X-ray diffraction to discover the shape of DNA.
What is Chargaff’s Rule?
Chargaff’s Rule revealed that DNA from different cells of species contain the same percentage of the four bases, A,T,C, and G.
What does each nucleotides contain?
A five carbon sugar.
Phosphate group.
N containing aromatic base.
Purine(Adenine and Guanine)
Pyrimidines(Cytosine, Thymine and Uracil)
Describe the Double Helix Model.
The sugar phosphate backbones are on the outside of the helix with the bases on the inside. There are 10 pairs of nucleotide per complete turn and 0.34 nm per nucleotide pair. The diamter is 2 nm with enough to pair A=T and C=G. The two strands are held by hydrogen bonds.
What’s the difference between nucleoside and nucleotides?
Nucleoside only contains a base and sugar. Nucleotides contains a base, sugar, and a phosphate group.
What are some key differences between RNA and DNA?
DNA is double-stranded, forming a double helix, while RNA is usually single-stranded. The sugar in DNA is deoxyribose, whereas RNA contains ribose. Furthermore, DNA uses the bases adenine, thymine, cytosine, and guanine, while RNA uses adenine, uracil, cytosine, and guanine
What are the two types of DNA?
Naturally occurring right hand helix called B-DNA.
Left hand helix called Z-DNA.
What is the difference between eukaryotic and prokaryotics ribosomes?
- Eukaryotic ribsomomes(80S) are generally larger, while the prokaryotic ribosomes(70S) are smaller in size.
What is the central dogma of biology?
DNA serves as a template for the synthesis of an RNA molecule, which then directs the synthesis of a protein product.
Explain transcription.
Transcription is the first step in gene expression. It involves copying a gene’s DNA sequence to make an RNA molecule.
Transcription is performed by enzymes called RNA polymerases, which link nucleotides to form an RNA strand (using a DNA strand as a template).
Transcription has three stages: initiation(RNA polymerase binds to a region of genes called the promoter that signals DNA to unwind), elongation(the adding of nucleotides to the mRNA strand; RNA polymerase reads the unwound DNA strans and build the mRNA molecule) and termination(RNA polymerase crosses a stop(terminantion) sequence in the gene; mRNA strands detach from DNA).
Shorten: a segment of DNA(a gene) that directs the synthesis of a complementary molecule of messenger RNA.
Explain translation.
Translation, as related to genomics, is the process through which information encoded in messenger RNA (mRNA) directs the addition of amino acids during protein synthesis. Translation takes place on ribosomes in the cell cytoplasm, where mRNA is read and translated into the string of amino acid chains that make up the synthesized protein.
Shorten: a ribosome, a complex of ribosomal RNA and proteins, attaches to the mRNA to read the coded information, whereas transfer RNA(tRNA) molecules bring the correct amino acids to add to the polypeptide chain.
How does DNA convert into a single strand?
DNA convert into a single strand by breaking the hydrogen bond.
What are the different forms of coiling in DNA?
Relaxed: no twisting of the DNA.
Positive supercoil: the DNA is twisted farther in the same direction as the helix.
Negative supercoil: the DNA is twisted in the opposite direction as the helix; increases access to proteins involved in replication or transcription.
What are the two types of topoisomerases?
Type I: Introduce a single DNA break to release any tension on the DNA.
Type II: Introduce double stranded breaks.
Ex: DNA gyrase in bacteria.
What is the bacterial chromosome called?
The nucleoid. The nucleoid is when the larger DNA molecule is bound to a few non histone proteins. The nucleoid is negatively supercoiled and folded into loops.
What are the types of plasmids?
F(fertility) factors: involved in the process of conjugation.
R(resistance) factors: carry genes providing drug resistance to the bacterium.
Col(colinogenic) factors: allows bacteria to secrete colicins, compounds that kill nearby bacteria that lack the col factor.
Virulence factors: enhance the ability to cause disease by producing toxic proteins.
Metabolic plasmids: produce enzymes required for certain metabolic reactions.
Criptic plasmids: have unknown functions.
What is called when DNA is bound to proteins?
Chromatin.
Why is DNA negatively charged?
DNA is negatively charged because of the phosphate group.The phosphate group in DNA (deoxyribonucleic acid) contains a negatively charged oxygen atom.
What are the 5 different types of histones?
H1, H2A, H2B, H3, and H4.
Chromatin contains about the same amount of all histones except H1.
What helps cut DNA?
Nuclease.
What are histones?
Histones are a group of small basic proteins(positively charged) with high lysine and arginine content.
What is cytogenetics?
Cytogenetics is the field of genetics that involves the microscopic examination of chromosomes.
What is a karyotype?
A karyotype is a photographic representation of the chromosomes.
Who is the father of genetics?
Gregor Mendel.
Explain hybridization.
Hybridization is the crossing between two individuals of different species, producing a hybrid.
Why did Gregor Mendel choose peas to study?
Gregor Mendel chose to use peas because they have a varity with distinct characteristics and their structure allowed for easy crosses.
What’s a monohybrid cross?
A monohybrid cross is the study of two variants within one cross.
What did Mendel hypothesized?
Mendel hypothesized that a pea pant contains two discrete hereditary factors, one from each parents. The factors may be identical or different. The two factors of a single trait are different such as dominant and recessive. During gamete formation, the pair factors will segregate so half of the gametes will recieve one factor and the other will recieve another.
What is pedigree analysis used for?
Pedigree analysis are usually used for determining the inheritance pattern of human genetic diseases.
What is the sum rule?
The sum rule is the probablitity that one of two(or more) equally exclusive events will occur is the sum of their individual probabilities.
Keyword: All and Or
Ex: If you roll a dice, you have a 1/6 chance of getting any number.
Explain the law of assortment.
During gamete formation, different pais of alleles segregate independently.
