Biology

DNA and Genetics

985 Questions

DNA and genetics questions explore molecular biology, DNA replication, and genetic engineering techniques. These topics are essential for various competitive exams requiring a strong foundation in life sciences. Practice these questions to understand complex biological processes thoroughly.

DNA replication mechanismsGenetic engineering techniquesGene editing toolsPolymerase chain reactionDNA sequencing methods

DNA and Genetics Questions

Multiple choice

In which of the following cases, it is preferable to use BLASTX?

  1. If the input sequence is a protein-encoding DNA sequence.
  2. If one is looking for protein homologs encoded in newly sequenced genomes.
  3. If a DNA sequence is to be used as the query.

  1. Only 1 and 2

  2. Only 1 and 3

  3. Only 2 and 3

  4. All of these

  5. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Yes, both are correct. If the input sequence is a protein-encoding DNA sequence, it is preferable to use BLASTX, which translates it in six open reading frames before sequence comparisons are carried out. If a DNA sequence is to be used as the query, a protein-level comparison can be done with TBLASTX. However, both programs are very computationally intensive and the search process can be very slow.

Multiple choice

Which of the following statements is/are TRUE?

  1. Praline is more accurate than Clustal.
  2. Alignment at the protein level is more sensitive than at the DNA level.
  3. Sequence alignment at the protein level is much more informative for functional and evolutionary analysis.

  1. Only 1

  2. Only 2

  3. Only 3

  4. All of these

  5. None of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Yes, this is the correct answer. Praline is profile based and has the capacity to restrict alignment based on protein structure information, and is thus much more accurate than Clustal. Alignment at the protein level is more sensitive than at the DNA level. Sequence alignment directly at the DNA level can often result in frameshift errors because in DNA alignment gaps are introduced irrespective of codon boundaries. Sequence alignment at the protein level is much more informative for functional and evolutionary analysis.

Multiple choice

Which of the following are consensus-based gene prediction programs?

  1. GenomeScan
  2. EST2Genome
  3. SGP-1
  4. GeneComber
  5. DIGIT

  1. Only 1, 2 and 3

  2. Only 2 and 4

  3. Only 3 and 4

  4. Only 3, 4 and 5

  5. Only 4 and 5
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Consensus-based gene prediction programs Because different prediction programs have different levels of sensitivity and specificity, it makes sense to combine results of multiple programs based on consensus. GeneComber is a web server that combines HMMgene and GenScan prediction results. DIGIT is another consensus-based web server. It uses prediction from three ab initio programs – FGENESH, GENSCAN, and HMMgene.

Multiple choice

Which of the following statements is/are false?

  1. In sequence assembly, k-mers are normally used during the construction of De Bruijn graphs.
  2. The choice of the k-mer size has many different effects on the sequence assembly.
  3. A lower k-mer size will increase the amount of edges stored in the graphs and decrease the amount of space required to store DNA sequence.

  1. Only 1

  2. Only 2

  3. Only 3

  4. Only 1 and 2

  5. Only 2 and 3
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

This option is correct. A lower k-mer size will decrease the amount of edges stored in the graphs and decrease the amount of space required to store DNA sequence.

Multiple choice

Which of the following carries genetic information from one generation to the other?

  1. Triglyceride

  2. Steroids

  3. Nucleic acids

  4. Phospholipids
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Nucleic acids allow organisms to transfer genetic information from one generation to the next. There are two types of nucleic acids: deoxyribonucleic acid, known as DNA and ribonucleic acid, known as RNA. When a cell divides, its DNA is copied and passed from one cell generation to the next generation.

Multiple choice

A gene is a _____________.

  1. kind of vitamin

  2. type of body cell

  3. unit of heredity

  4. none of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A gene is a segment in a chromosome found inside the nucleus of a living cell. The traits of an individual, such as the appearance, nature of the voice, resistance to certain diseases etc, coming down from ones ancestry are chemically coded in the genes. They not only contain the recipes for the production of body tissues and enzymes required for respiration and digestion etc,  even the time and the duration for various actions such as growing a beard and producing milk after pregnancy are precisely programmed.