Exam 2 - Review Flashcards
What conclusions did Beadle and Tatum make pertaining to the gene-protein relation?
A single gene encodes a single enzyme
What is the region of repetitive nucleotide sequences at the end of chromosomes termed?
Telomeres
What is the region on the chromosome where there spindle fiber attaches via the kinetochore? Essential for chromosome separation.
Centromere structure
What is the funciton of telomeres?
Protects the end of the chromosome from deterioration or from fusion with neighboring chromosome
What biological outcomes are associated with shorter telomeres?
Shorter life span and increased incidence of disease
What complex of proteins assoicated with centromeres of a chromosome aloow the spindle to attach during cell division?
Kinitochore
Cylindrical cell organelle, located near the nucleus in the cytoplasm of most eukaryotic cells, that divides in perpendicular fashion during mitosis.
Centriole
If a chromosome where to break and one of the fragments did not have a centromere what would occur?
The fragment without the centromere would degrade
Enzyme responsible for adding and removing turns in the coil (i.e. DNA coil).
Topoisomerase
What permits the attaction of histones to DNA?
Histones are positively charged and DNA is negatively charged
Complex formed by DNA wrapped around eight histone proteins.
Nucleosome
What is the difference in chromatin condensation between euchromatin and heterochromatin?
Euchromatin is less condensed and heterochromatin is more condensed
DNase I sensitivity sites tend to be at accesible chromatin. What can this be used to determine?
Gene expression
By testing DNase I sensitivity throughout a embryo’s lifetime researchers were able to conclude what?
Chromatin structure changes in the course of transcription
A heritable alteration of phenotype because of altered chromatin structure without changing DNA sequence.
Epigenetics
Tract of tandemly repeated DNA motif that ranges in length from two to five nucleotides typically repeated 5-50 times.
Microsatellite DNA
What is the goal of amplifying microsatellite DNA sequences?
Can help determine a persons “DNA fingerprint” as well as DNA profiling in cancer diagnosis
What would occur if the positive charges on the histone proteins was neutralized?
They would separate from DNA and the would not be attracted to each other
Proposes that mitochondria and chloroplasts were once free-living bacteria.
Endosymbiotic theory
What evidence supports the endosymbiotic theory?
Mitochondria/Chloroplast are similiar to eubacteria (i.e. circulat DNA, no histones, 70s ribosomal subunit, and grow via binary fission)
What is a popular example of uniparental inheritance of organelle-encoded traits in mammals?
Mitochondrial DNA is nearly exclusively inherited from female parent
The presence of more than one type of organellar genome.
Heteroplasmy
Seperation of organlles in heteroplasmic cells is guided/random.
Random
What has a higher mutaiton rate in vertebrates mitochondrial DNA or nuclear DNA?
Mitochondrial DNA