Chapter 15: Genetic Variation Flashcards
What is the definition of Genetic Variation?
Genetic differences that exist among individuals in a population at a particular point in time
What is the difference between a Genotype and a Phenotype?
Genotype: the genetic makeup of a cell or organism
Phenotype: an individual’s observable characteristics (i.e., height, eye color, weight, color blindness, etc.)
Who was Gregor Mendel was and what did he accomplish in his studies? What are his 3 Fundamental Laws of Inheritance?
“THE FATHER OF GENETICS”
Through his work on pea plants, discovered the 3 Fundamental Laws of Inheritance:
1- Lawof Segregation: when gametes form, alleles are separated so that each gamete carries only one allele for each gene
2- Lawof Independent Assortment: the segregation of alleles for one gene occurs independently to that of any other gene
3- Law of Dominance: recessive alleles will be masked by dominant alleles
What is a Punnett Square? Know how to use one.
A chart that allows you to determine the expected percentages of different genotypes in the offspring of two parents. A Punnett square allows the prediction of the percentages of phenotypes in the offspring of a cross from known genotypes.
What are VNTR and RFLP? How are they are accomplished?
VNTR: Variable Number of Tandem Repeats
- because the # of repeats of a certain DNA sequence between individuals varies, we need to determine how many repeats are present
(# of repeats = VNTR weight/sequence weight)
RFLP: Restriction Fragment Length Polymorphism
- technique using restriction enzymes to identify variations in homologous DNA sequences
What are SNPs?
Single Nucleotide Polymorphisms:
Locations within the human genome where the type of nucleotide present (A,T,G, or C) can differ between individuals.
- SNPs are the most common type of genetic variation found among people.
- At least 1% of a population must contain the same nucleotide variation for it to be considered a SNP.
What is the process of DNA fingerprinting?
Running DNA (VNTRs, RFLPs, SNPs) through gel electrophoresis to determine DNA similarity/differences between individuals
What is CNV genotyping?
Copy Number Variations (CNVs) are genomic alterations that result in an abnormal number of copies of one or more genes. Structural genomic rearrangements such as duplications, deletions, translocations, and inversions can cause CNVs.
- During CNV, researchers look for the intensity of fluorescence in addition to what spots on the microarray fluoresce.
- Copy number variation can be detected by the intensity of hybridization or fluorescence on a DNA microarray.
What is one diseases that results from the lack of a sex chromosome?
Turner Syndrome: a condition that affects only females, results when one of the X chromosomes (sex chromosomes) is missing or partially missing. T- causes a variety of medical and developmental problems, including short height, failure of the ovaries to develop and heart defects.
What is one disease that results from an additional sex chromosome?
Klinefelter syndrome: adversely affects testicular growth, resulting in smaller than normal testicles, which can lead to lower production of testosterone. The syndrome may also cause reduced muscle mass, reduced body and facial hair, and enlarged breast tissue.
