Genome Biology - Unit 1.1 + 1.2 MCQ's

Can you guess which one of the cell types below does not contain any DNA and would not be useful for extracting a DNA sample for DNA sequencing?

Red blood cell

In which of these eukaryotic cellular organelles is DNA found?

Nucleus & Mitochondria

If DNA is represented as twisted ladder, sides of the ladder are ______

Sugar-phosphates

If DNA is represented as a twisted ladder, the rungs/ steps of the ladder are ______

Base pairs

Chose the correct (true) statements from the following list (more than one answer is correct):

• The DNA in the genomes of humans, mice, fruit flies, and bacteria obeys Erwin Chagraff's base pairing rules.

• The number of Cytosine bases always equals the number of Guanine bases in a short piece of DNA (150 base pairs in length).

• The number of Adenine bases always equals the number of Thymine bases in a long piece of DNA (1,500,000 base pairs in length).

• The balance (proportion) of A=T and G=C pairs is the same in the genomes of humans, mice, and fruit flies.

• Thermus thermophilus bacteria have a G=C content of 69% in their genomes, that implies that its genome has 31% A=T content.

• The DNA in the genomes of humans, mice, fruit flies, and bacteria obeys Erwin Chagraff's base pairing rules.

• The number of Cytosine bases always equals the number of Guanine bases in a short piece of DNA (150 base pairs in length).

• The number of Adenine bases always equals the number of Thymine bases in a long piece of DNA (1,500,000 base pairs in length).

• Thermus thermophilus bacteria have a G=C content of 69% in their genomes, that implies that its genome has 31% A=T content.

Enter the complementary strand sequence for the single DNA strand sequence shown here

GCCGTAGCATACTC

Which of the following scientists can we confidently say contributed to the discovery of DNA. (more than one answer is correct):

• Watson & Crick

• Franklin & Wilkins

• Linus Pauling

• Erwin Chargaff

• Watson & Crick

• Franklin & Wilkins

• Erwin Chargaff

Before the discovery of DNA, biologists reasoned that there must be some kind of molecule that enables traits (features of organisms) to be passed on from one generation to the next. But such a molecule would have to have some very important features, these are: (more than one answer is correct):

• Stability over long periods of time

• Mutability

• Made of proteins

• Made of nucleic acids

• Stability over long periods of time

• Mutability

Match each terms with its correct explanation:

1. Mutation

2. Replication

3. Chargaff’s Rules

• In any DNA molecule, the amount of A bases is always equal to the amount of T bases and the amount of G bases is always equal to the amount of C bases.

• Cells can readily make exact copies of their DNA.

• A change in a DNA base sequence that can happen naturally and can sometimes cause differences in traits or lead to diseases.

1. Mutation - A change in a DNA base sequence that can happen naturally and can sometimes cause differences in traits or lead to diseases.

2. Replication - Cells can readily make exact copies of their DNA.

3. Chargaff’s Rules - In any DNA molecule, the amount of A bases is always equal to the amount of T bases and the amount of G bases is always equal to the amount of C bases.

   
   

Choose the one correct statement from the list below.

DNA is composed of long chains of molecules called nucleotides.

In the context of non-Mendelian inheritance, how might a geneticist explain the variation in skin color among humans, considering the influence of multiple genes and environmental factors?

Deoxyribose

Choose the correct response below to fill in the blank.

The phosphate group helps to form the backbone of a DNA strand by linking a carbon (3') of one deoxyribose to the another carbon (5') of the next deoxyribose through _____________ bonds.

Phosphodiester

Choose the correct response below to fill in the blank.

In nucleotides, the nitrogenous bases are connected to the deoxyribose sugar at the the 1' carbon position through _____________ bonds

Glycosidic

DNA is found in the nucleus of all cells

False

DNA is usually found in cells in the double stranded form, i.e., dsDNA

True

The sugar-phosphate backbone of DNA is of no importance to the biology of DNA.

False

Pieces of DNA are measured using the numbers of base pairs (bp) present in them.

True

Prokaryotic DNA is found in a region of the cell known as the

Nucleoid

The nitrogenous base Adenine (A) always pairs with which other base?

Thymine

In eukaryotic cells, cell division known as mitosis occurs after which one of the following events?

Replication of DNA in S phase of the cell cycle

A gene is known to code for a protein that contains 10 amino acids. How many codons are in this gene?

10

A gene is known to code for a protein that contains 10 amino acids. How many nitrogenous bases in total are in the codons of this gene?

30

A molecular biologist is working with a piece of dsDNA that measures 10bp. Which of the following statements is correct? Note: more than one answer is correct:

• This piece of DNA contains 10 bases in total

• This piece of DNA contains 20 bases in total.

• This piece of DNA contains 10 base pairs in total.

• This piece of DNA contains 10 deoxyribose sugars.

• This piece of DNA contains 20 deoxyribose sugars.

• This piece of DNA contains 10 nucleotides

• This piece of DNA contains 20 nucleotides

• This piece of DNA contains 20 bases in total.

• This piece of DNA contains 10 base pairs in total.

• This piece of DNA contains 20 deoxyribose sugars.

• This piece of DNA contains 20 nucleotides

Choose the one correct statement from the list below.

DNA in eukaryotes is wrapped around histones forming nucleosomes which then combine to form chromatin which then coils up to form chromosomes.