Question

Choose (True) or (False) for the next questions. (1 point each):-

- The size of nucleosome is constant (?200 bp) in all organisms. ..………

- The length of linker of the nucleosome will affect the length of loop of chromatin. ..………

- Point mutation which cause inhibition of transcription in operon. ..………

- Transcription of operon lead to form polycistronic mRNA. ..………

- Open reading frame is region between the start and stop codon. ..………

- Satellites act as functional role in stability of DNA. ..………

- DNA is coiled around histone core to produce 1.8 turns with ?200 bp. ..………

- The lac operon transcribed, if both lactose and glucose are present. ..………

- Ribose sugar in RNA is more stable than deoxyribose in sugar. ..………

- - Chargaff rules concluded that the percent composition of adenine is the same for all species. ..………

Answer 1

Answer 1) false, the length of linker of nucleosome is not constant in all organisms. because Linker DNA length ranges between ~20–90 bp and varies among different species, tissues, and even fluctuates within a single cellular genome.

Answer 2) True,, as size of linker DNA varies from species to species chromatin remodeling and modifying mechanisms target these regions of the nucleosome to reposition nucleosomes, disassemble nucleosomes and exchange variant histones.

Answer 3)False, because different type of mutation can alter the function of lac operon.

Answer 4) false. expression of prokaryotic operons leads to the generation of polycistronic mRNAs, while eukaryotic operons lead to monocistronic mRNAs.

Answer 5) true, open reading frame is a region between start and stop codon.

Answer 6) true, satellites provide stability to DNA.

Answer 7)false

Answer 8) false, lac operon transcribed lactose, when glucose is not present.

Answer 9) true.

Answer 10) false, adnine percentage is different in all species.