Chromosome organization and molecular structure

Which of the following supports the argument that viruses are nonliving?

• Their DNA does not encode proteins

• They have RNA rather than DNA

• They are not cellular

• They do not evolve

What kind of genetic material can be found in viruses?

• dsDNA

• RNA

• ssDNA

• All of the above

Viruses _____.

• use the host cell to copy themselves and then viruses to synthesize their own proteins

• metabolize food to produce their own ATP

• use the host cell to copy themselves and make viral proteins

• manufacture their own ATP, proteins, and nucleic acids

Which of the following features would characterize a lytic cycle of viral infection?

• it endows the host bacterium with the ability to cause disease

• it always leads to lyses of the host cell

• it is seen only with viruses that infect bacteria

• it is seen only with viruses that infect plants

Which statement is incorrect about bacterial chromosomes

• Are circular in shape

• There can be multiple copies of chromosomes in a bacterial cell

• Consist of only structural genes

• There is a single origin of replication

How are circular bacterial chromosomes compacted to fit a bacteria cell?

• First the circular chromosome get folded into loop domains then further supercoiled

• First the circular chromosome get supercoiled then further folded into loop domains

• First the circular chromosome enters the cell and produces copies of itself with the host material

• First the circular chromosome become uncoiled then cut using enzymes

Negative supercoiling is mediated by DNA Gyrase to introduce twists in the circular chromosome

• True

• False

Positive supercoiling relaxes the twisting of the chromosome back into circular shape and is mediated by Topoisomerase I

• True

• False

Why is the genome size not an indicator of the number of genes

• The big size can be due to multiple genes that encode proteins

• The big size can be due to accumulation of repetitive sequences

• The big size can be due to the size of the organism itself is big

• The big size can be due to genotypic variation and environment

In eukaryotic chromosomes, what are required for chromosomal replication and segregation.

• Origins of replication

• Centromeres

• Telomeres

• All of the above