Chapter 5 · Condensation of DNA & Structure of Genome: practice questions

A chromosome is composed mainly of:

• AFats and carbohydrates
• BWater and salts
• CDNA and histones
• DRNA only

The complete set of genetic material (DNA) in a living organism is called the:

• AChromatid
• BNucleosome
• CGenome
• DGene

The form that DNA and histones take in a non-dividing cell (thin and long) is called:

• AThe nucleotide
• BChromatin
• CThe condensed chromosome
• DThe gene

When comparing chromatin and the chromosome:

• AThey are two completely different substances in composition and do not change into each other
• BChromatin is a thin, extended form and the chromosome is a condensed form during division
• CThe chromosome contains no DNA and is formed from RNA wrapped around histones
• DChromatin is found only in bacteria and is absent from the nucleus of human cells

A single nucleosome consists of DNA coiled around:

• AA group of histone molecules (eight)
• BA bacterial plasmid (a circular ring)
• CA single histone molecule (just one)
• DAn RNA molecule (a single mRNA strand)

Which of the following is described as 'non-coding'?

• AThe intron
• BThe protein-producing gene
• CThe exon
• DThe codon

A DNA molecule carries the instructions for making 3 different proteins. What is the minimum number of genes it carries?

• ASix genes
• BIt carries no genes
• COne gene
• DThree genes

Why does the human genome contain a large number of nucleotides even though only a small proportion codes for proteins?

• ABecause DNA is duplicated during translation, which doubles the number of nucleotides in every gene
• BBecause all nucleotides code for proteins (every region of the genome is made of exons)
• CBecause histones are made of DNA, so their nucleotides are added to the nucleotides of the genome
• DBecause a large part of the genome consists of non-coding regions (introns and regulatory regions)

What is the main difference in genome organization between prokaryotes and eukaryotes in terms of non-coding regions?

• AEukaryotes have no genes, while prokaryotes have many of them
• BEukaryotes have many introns, while prokaryotes rarely contain them
• CProkaryotes have more introns, while eukaryotes rarely contain them
• DBoth have no non-coding regions, as all their DNA codes for proteins

Before replication, one human chromosome carries about 2000 genes. Which description of this chromosome is correct?

• AAbout 2000 separate DNA molecules, one for each gene, held together by histones
• BOne DNA molecule whose genes are segments separated by non-coding DNA
• CTwo DNA molecules, each carrying 1000 of the genes, joined at the centromere
• DOne DNA molecule carrying one gene that is repeated about 2000 times