Term
| What are the 4 substrates used by DNA polymerase (deoxynucloside triphosphates)? |
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Definition
1) dATP
2) dCTP
3) dGTP
4) dTTP |
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Term
| Which direction does the DNA chain grow in during PCR? |
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Definition
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Term
| What are the 3 steps of the PCR cycle? |
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Definition
1) Denaturation of DNA via heating
2) Lowering the temperature of the process to allow the short DNA primer hybridization
3) DNA synthesis by a heat-stable DNA polymerase (derived from a thermophilic organism) |
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Term
The amount of target DNA doubles in each PCR cycle. So, for example:
After 1 PCR cycle, there are __________ copies of each initial target sequence.
After 10 cycles, there are __________ copies.
After 20 cycles, there are __________ copies.
After 30 cycles, there are __________ cycles.
Usually the PCR reaction plateaus after __________ cycles. |
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Definition
1) 2
2) 1,024
3) 1,000,000 (2^20)
4) 1,000,000,000 (2^30)
5) 30 |
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Term
| True or False: The PCR achieves in a few days what DNA cloning can do after a few hours or more of work. |
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Definition
| 1) FALSE: The PCR achieves in a few HOURS what DNA cloning can do after a few WEEKS or more of work. |
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Term
| What is one main prerequisite necessary for PCR to take place? |
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Definition
| 1) PCR requires two primer DNA chains that will hybridize to the 2 ends of the target DNA (this first requires that one first clone and sequence the target DNA). |
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Term
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Definition
| 1) Linearly arranged on a chromosome for many genes / chromosome. |
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Term
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Definition
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Term
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Definition
| 1) Each diploid individual has 2 copes of each chromosome (called homologous chromosomes), one from the mother and one from the father. |
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Term
| What is a genotype? A phenotype? |
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Definition
1) The genotype is the overall genetic blueprint of our genes.
2) A phenotype is the visible outcome derived from the genotype. The phenotype is determined by the interaction of the genotype and its environment. |
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Term
| What is homozygous? Heterozygous? Hemizygous? |
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Definition
1) In a diploid, 2 identical alleles of a gene in the 2 homologous chromosomes is said to be homozygous.
2) In a diploid, 2 different alleles of a gene in the 2 homologous chromosomes is said to be heterozygous.
3) In a diploid, if a copy of a gene is deleted, haploidy is caused and the result is said to be hemizygous. |
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Term
| What does it mean for a gene to be monomorphic? Polymorphic? |
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Definition
1) A gene is monomorphic when only one allele is known for a gene.
2) A gene is polymorphic when more than one allele are known for a gene. |
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Term
| True or False: Most of the DNA in a human genome does not code for genes. |
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Definition
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Term
| What are 2 methods for studying mutations? |
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Definition
1) DNA manipulation
2) Analysis methods |
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Term
| Describe a single nucleotide polymorphism (SNPs). |
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Definition
| 1) Two different humans have an average of one change for ~1,200 nucleotides. These changes can occur in any base pair and are randomly distributed in the genome. Descendants of an individual will inherit the sequence of the parent. Therefore, by DNA sequencing, one can follow such single nucleotide changes (SNPs). |
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Term
| Describe a restriction fragment length polymorphism (RFLPs). |
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Definition
| 1) Scattered within the genome are recognition sites for several hundred different known restriction endonucleases. A mutation in the recogniztion sequence leads to the loss of the cutting site; conversely, a change in a nucleotide can lead to the generation of a new cutting site. These variations in cutting sites are inherited by the descendants of an individual and can also be followed by DNA methodologies. Depending upon where the gain / loss of a restriction site has occurred relative to the hybridization probe, one may see a change in size of DNA bands in a southern blot or to the appearance / disappearance of DNA bands. |
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Term
| True or False: RFLPs are recessive. |
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Definition
| 1) FALSE: RFLPs are CODOMINANT |
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Term
| Describe simple sequence (tandem) repeat polymorphisms (SSRPs or STRPs). |
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Definition
| 1) There are tandemly repeated sequences scattered within our genome. Once class is called the variable number of tandem repeat sequences which are 10-60 nucleotide long sequences repeated several times. As always, different individuals have different numbers of repeats in a location and the number of location varies. This results in different numbers and size bands in southern blots. |
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Term
| What is microsatellite DNA? |
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Definition
| 1) Stretches of dinucleotide repeat sequences (such as GCGCGC). PCR amplification of these repeated sequences uses 2 primers that hybridize to flanking DNA also generate different size DNA bands in a gel. |
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Term
| What are copy-number polymorphisms (CNPs)? |
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Definition
| 1) In addition to SNPs and simple sequence repeat polymorphisms (SSRPs and VNTRs) there are much larger size variations (thousands to a few million base pairs) that have the potentiality to lead to a variety of hereditary diseases. |
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Term
| What are 3 uses for DNA markers? |
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Definition
1) Genetic mapping of genes in humans (for mapping of e.g. the disease genes in humans)
2) Evolutionary and anthropological genetics (ranging from SNPs to CNVs, DNA markers have been used to map genetic relatedness through evolutionary relationships).
3) Forensics, paternity testing, etc. (DNA markers can now be used to identify criminals [fingerprinting] and to identify the remains of accident victims [car accidents]). |
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