QB_D - BIO320 Question bank D; lectures 21-23. Eukaryotic...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
BIO320 – Question bank D; lectures 21-23. Eukaryotic chromosomes, chromatin & gene expression 1. To study how retrotransposons are copied to new sites in the genome, an intron was placed experimentally into a cloned yeast retrotransposon, Ty1, and the modified Ty1 DNA was inserted into a yeast chromosome. Further transpositions of this Ty1 element into other chromosomal sites were found to be missing the intron. This experiment showed that: A. Yeast cells excise introns from their chromosomal DNA. B. Ty1 transposition involves an RNA intermediate that can undergo splicing. C. The Ty1 transposase has spliceosome activity. D. Yeast cells lack a splicing mechanism. E. Ty1 transposition involves a DNA intermediate that can undergo splicing. 2. A non-autonomous DNA transposon is no longer independently mobile because it has. .. A. ...lost its terminal repeat sequences but retained its transposase gene function. B. ...been inserted into a gene. C. ...lost its transposase gene function but retained its terminal repeat sequences. D. ...been inserted close to an enhancer. E. ...become integrated into a chromosome. 3. These are various substructures in the arrangement of eukaryotic DNA. Number them in order of increasing size (i.e. diameter or thickness): DNA helix, chromatid, 30nm fiber, nucleosome, chromosome, histone octamer. 4. The total length of the DNA in a diploid set of human chromosomes is about 2 meters, yet this DNA must fit into a nucleus that is less than 10 mM (10 -5 m) in diameter. This is accomplished by: A. Removal by splicing of the introns and other non-coding regions that make up the bulk of the DNA. B. Several levels of coiling and looping, beginning with the coiling of DNA into nucleosomes. C. Cutting the DNA into short lengths by DNAse I and other endonucleases. D. Hyperacetylation of histone proteins. E. Inactivation and condensation of one homolog from each chromosome pair. 5. Which of the following statements about the histones and nucleosomes in eukaryotic chromatin is FALSE: A. Nucleosomes recognize and bind to specific DNA base sequences. B. The core nucleosome comprises two copies each of four histone proteins. C. The DNA helix is wound around the outside of each nucleosome. D. Modification of histones can affect chromatin structure and gene expression. E. Histones are basic proteins with positively charged residues that interact with the negatively charged phosphate groups on DNA 6. Which of the following structures enables separation of sister chromatids by spindle microtubules at mitosis? A) centromeres B) telomeres C) origins of replication D) nucleosomes E) DNAse hypersensitive sites 7. Which of the following statements about histones is FALSE A) Positively charged amino acids on histones contact the negatively charged phosphates on the DNA backbone. B) Adding acetyl groups to specific amino acids on histones can change the condensation state of chromatin.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 04/21/2010 for the course BIO 89329 taught by Professor Hollingsworth during the Spring '10 term at SUNY Stony Brook.

Page1 / 14

QB_D - BIO320 Question bank D; lectures 21-23. Eukaryotic...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online