Topics-
Products +
     

DNA Questions and Answers (Q&A)

The correct answer to this question is – Yes. About 99.9% of human DNA is identical from one person to another. This makes a large portion of our DNA be the same repetitive sequences. The 0.1% left might sound insignificant to you, but the 0.1% makes the difference. It will amaze you to know that the human genome contains up to 3 billion base pairs.

This means 0.1% of the total human genome that is unique to a person is about 3 million base pairs. These three million base pairs, which make the difference, lies the genetic material that determines features unique to you. This includes your hair color, eye color, risk of certain diseases, risk of obesity, and so much more.

1 Answer

The correct answer to this question is option B – Every DNA nucleotide contains a sugar, a phosphate group, and a nitrogen base. DNA is the acronym for Deoxyribonucleic acid. It is the material that carries genetic information in living organisms. DNA is a double-helical structure. It is made of two strands that are tightly joined by hydrogen bonds. DNA nucleotides are made from deoxyribose sugar, a phosphate group, and one of the following nitrogenous bases - adenine, guanine, cytosine, and thymine.

DNA is held together by proteins called histones, and they are contained in chromosomes present inside the nucleus of a cell. Option A is incorrect because both short and long DNA is contained in chromosomes inside the nucleus. Option C is incorrect because DNA consists of two strands, not one strand, and they are joined by hydrogen bonds. Option D is incorrect because irrespective of the length of DNA, they are always twisted into a double helix.

1 Answer

Anticodon. The 3-antinucleotide code on tRNA is called anticodon. In the process of translation (protein synthesis), aside ribosome and mRNA, tRNA is also required to begin the process. Transfer RNAs commonly referred to as tRNAs are RNAs that bring amino acid to the ribosome. It works to match the codon on mRNA with the amino acids that it codes for. Each tRNA carries a set of 3 nucleotides referred to as anticodon.

Anticodons bind to specific codons on the mRNA. Aminoacyl-tRNA synthetase is the enzyme that functions to load tRNA with the amino acid sequence for the codon. In the first stage of translation (initiation), the subunits of the ribosome come together with mRNA along with the first tRNA to begin the process of translation. In the second stage (elongation), tRNA brings amino acid to the ribosome, and this begins to form chains. At the end-stage (termination), the polypeptide produced is release.

1 Answer

Codon. The 3-nucleotide code on mRNA is called codon. Codon represents a sequence of 3 nucleotides that is part of genetic code. They are often seen in mRNA. Messenger RNA is the type of RNA produced during transcription. It carries genetic information from DNA to the ribosome. There are 64 codons. Each codon contains three nucleotides.

Sixty-one of the code for amino acids and 3 of them are called stop codons because they terminate the process of translation when present. The three stop codons are UAA, UAG, and UGA. They do not code for any amino acid, and when present, the ribosomes stop and fall off the mRNA. Although we have 61 codons that code for amino acid, there are only 20 amino acids known. This means about 2 to 3 codons code for the same amino acid sequence.

1 Answer

RNA polymerase. The RNA polymerase is the enzyme that helps in transcription. It helps in the synthesis of mRNA, which basically copies DNA sequence into RNA sequence. RNA polymerase works from the 3’ end to the 5’ end of the template strand of DNA. This helps to create the new growing strand growing from 5’ to 3’ direction. In prokaryotes, RNA polymerase is made up of subunits, including a sigma factor but in eukaryotes.

There are 5 RNA polymerases. RNA polymerase I produce the largest amount of RNA. They synthesize ribosomal RNA, which forms most parts of ribosomes. RNA polymerase II functions in transcription. It is involved in the synthesis of mRNA. RNA polymerase III synthesizes transfer RNA. RNA polymerase IV and V are found only in plants.

1 Answer

The correct answer is option E – Permanent, heritable alterations in the base sequence of the DNA. A mutation refers to changes or alterations of the base-pair sequence in genetic material. These alterations are permanent and cannot be corrected. Mutation can be inherited or acquired as a result of environmental factors such as smoking and sunlight.

There are three types of mutations – silent, missense, and nonsense mutation. If the amino acid produced is different from the initial amino acid at the site of the change, a nonsense mutation or missense mutation has occurred. This will affect the function and structure of the protein produced. This mutation also causes premature signals to stop making protein resulting in a shortened protein that will not function properly.

1 Answer

DNA fingerprinting is used in many different ways for a variety of reasons. It can be used to study and potentially even cure diseases, to locate a relative or to prove that you are related, or to provide evidence if you committed a crime and left behind some DNA.

In order to do DNA fingerprinting, first you must collect a sample which can include blood, a hair, saliva, and even sweat. It is most commonly done with a blood test or by swabbing the inside of your cheeks. Then it is broken down chemically and dissolved in water. Once this is finished then they will take just a section of the DNA from the sample and study it.

1 Answer

The correct answer to this question is S phase. The cell cycle is the cycle that allows the growth and division of cells for the purpose of reproduction and repair of cells and tissue. DNA replication occurs during the S phase of the cell cycle. The cell cycle is divided into two parts – the interphase and mitotic phase. Interphase is further divided into G1, G2, and S phase. In interphase, the cell grows, and DNA is replicated before the mitotic phase occurs.

In this phase, materials of DNA are doubled before the cell cycle progresses to mitosis. The S phase is the synthesis phase when DNA is replicated. This phase occurs between G1 and G2 phases. In the mitotic phase, the daughter nuclei are formed by the segregation of the duplicated chromosome. The cytoplasm is also divided to form 2 daughter cells at the end of the cell cycle.

1 Answer

Something that codes for our characteristics

1 Answer

The correct answer is option B – Ligase. The enzyme that is mutant in the bacteria is ligase. Ligase is an enzyme that functions to join large molecules to form chemical bonds between them. Since the DNA molecules discovered after heating are numerous single-stranded DNA molecules, around 1000 nucleotides are found, it shows that the function of ligase is not present in the bacteria.

Option A is incorrect because DNA polymerase functions in DNA replication to synthesize new DNA. Option C is incorrect because helicase is an enzyme that functions to unwind DNA strands to begin the process of DNA replication. Option E is incorrect single-strand DNA binding is a protein that binds to the single strand regions of the DNA to maintain DNA metabolisms such as DNA replication, recombination, and DNA repair.

1 Answer

Loading, please wait...

Email Sent
We have sent an email to your address "" with instructions to reset your password.