Biology

Molecular Biology and Genetics

985 Questions

Molecular biology and genetics explore the structure and function of DNA, RNA, genetic mutations, and heredity. Understanding these building blocks of life is essential for most biology examinations. Review these practice questions to test your molecular genetics knowledge.

DNA structure and basesGenetic mutationsNucleic acids compositionDNA sequencing and replication

Molecular Biology and Genetics Questions

Multiple choice biochemical polymers polymerisation chemistry

A nucleotide consists of

  1. carbon sugar

  2. nitrogen containing base

  3. phosphoric acid

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A nucleotide is made up of the following
Sugar ring, base (adenine, guanine, cytosine, thymine/uracil), phosphate molecule.
The sugar ring is made up of carbon atoms. The bases are nitrogenous. So, all of these are true.

Multiple choice biochemical polymers polymerisation chemistry

Which among the following sequence defines Ribonucleotide?

  1. Ribose sugar $+$ Nitrogenous base
  2. Ribose sugar $+$ Protein
  3. Ribose sugar $+$ Phosphoric acid
  4. Ribonucleoside $+$ Phosphate group
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A ribonucleotide consists of a ribonucleoside plus a phosphate group attached to it. A ribonucleoside itself is made of a ribose sugar and a nitrogenous base.

Multiple choice biochemical polymers polymerisation chemistry

A nucleotide is made up of:

  1. a base and sugar

  2. a base and phosphate unit

  3. a sugar and phosphate unit

  4. a sugar, a base and a phosphate unit
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Sugar + Base + a phosphate unit constitute one nucleotide.
This is the definition of a nucleotide.

Multiple choice biochemical polymers polymerisation chemistry

The sequence between nucleotide triplets and the amino acids is called

  1. transcription

  2. duplication

  3. genetic code

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

Genetic code is the sequence between nucleotide triplets and the amino acids. The whole phenomenon is called as Central Dogma. It's a really important phenomenon and a lot of cell organelles are involved : DNA, mRNA, Ribosomes, etc.

Multiple choice biochemical polymers polymerisation chemistry

The genetic language of nucleotides translates into language of:

  1. carboxylic acids

  2. amino acids

  3. ketones

  4. aldehydes
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

During protein synthesis, the following process occurs:
The information stored in DNA is coded in the form of RNA in a process called transcription.
Next, the RNA code is processed in ribosomes and ultimately proteins (made of amino acids) are made. So, B is correct.

Multiple choice biochemical polymers polymerisation chemistry

Which of the following is not present in nucleotide?

  1. guanine

  2. cytosine

  3. adenine

  4. tyroxine
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Tyroxine is not present in nucleotide. Nucleotide consists of adenine, guanine, cytosine, thymine, uracil, molecule of sugar and one of phosphoric acid.

Multiple choice biochemical polymers polymerisation chemistry

The relationship between the nucleotide triplets and the amino acids is called:

  1. translation

  2. transcription

  3. replication

  4. a genetic code
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The relationship between the nucleotide triplets and the amino acids is called a genetic code.
This determines the sequence of amino acids in the proteins that are synthesized.

Multiple choice biochemical polymers polymerisation chemistry

When adenine is attached to ribose sugar, it is called adenosine. To make a nucleotide from it, it would require?

  1. Oxygenation

  2. Addition of a base

  3. Addition of phosphate

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

Answer:- (C) addition of phosphate

Adenine forms adenosine, a nucleoside, when attached to ribose. It forms adenosine triphosphate (ATP), a nucleotide, when three phosphate groups are added to adenosine.

Multiple choice botany biotechnology and its applications biopiracy biotechnological regulations principles and process of biotechnology

Genetic material with potential value is

  1. DNA

  2. Genetic resources

  3. RNA

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

Genetic resources are the genes found in plants and animals that are of actual or potential value to people. Through the use of new biotechnologies, genes from any organism can be transferred to another. Plant and animal breeders, for example, use genes found in wild species, and genetically engineered organisms are now being used for new industrial applications such as mining, wastewater treatment, etc. Thus option B is the correct answer. 

Multiple choice biology constitutes of diet need for nutrients nutrients needed by the body balanced diet and malnutrition

Which of the following is not the molecule of information :

  1. Protien

  2. DNA

  3. RNA

  4. Deoxyribose
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

DNA contains the genetic information necessary for the synthesis of RNA and thereby all proteins necessary for the cell to function. RNA is a sequence of nucleotides that contain information for the synthesis of proteins. Deoxyribose is a sugar present in the nucleotides of DNA. Proteins are also provide  information. 

So, the correct option is  'Deoxyribose'

Multiple choice botany option b: biotechnology and bioinformatics insertion and ligation of dna cutting, insertion and ligation of dna biotechnology in agriculture

In which of the following combinations, the compounds in ascending order based on their molecular weights are arranged

  1. DNA, RNA, AMP, ADP, ATP

  2. DNA, RNA, ATP, ADP, AMP

  3. AMP, ADP, ATP, RNA, DNA

  4. AMP, ATP, ADP, DNA, RNA
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The arrangement of compounds in ascending order according to their molecular weight is AMP, ADP, ATP, RNA, DNA.

Multiple choice botany option b: biotechnology and bioinformatics insertion and ligation of dna cutting, insertion and ligation of dna biotechnology in agriculture

In E.coli, a finished polypeptide has $162$ amino acids of which the first amino acid is not methionine compound. How many nucleotides of DNA are required to code this polypeptide?

  1. $486$
  2. $54$
  3. $489$
  4. $492$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A polypeptide of 162 amino acids requires 162 codons. Each codon consists of 3 nucleotides. 162 * 3 = 486 nucleotides.

Multiple choice botany option b: biotechnology and bioinformatics insertion and ligation of dna cutting, insertion and ligation of dna biotechnology in agriculture

When E coli with DNA $^{15}N ^{15}N $ is allowed to grow in a medium containing $^{14}N$ the number of DNA strands with $^{15}N$ after five generations is: 

  1. 1

  2. 2

  3. 8

  4. 16

  5. 30
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

DNA replication is semi-conservative. Starting with one fully heavy DNA molecule containing two N-15 strands, after 5 generations (32 total DNA molecules), only the two original strands from the parent molecule retain N-15, each ending up in a separate hybrid DNA molecule.

Multiple choice biology structure and functions of living organisms -ii dental care, eye care and hair care dental care and dental diseases salivary glands

In salivary gland chromosomes/polytene chromosomes, pairing is?

  1. Absent

  2. Occasional

  3. Formed between non-homologous chromosomes

  4. Formed between homologous chromosomes
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Polytene chromosomes found in the salivary glands of dipteran insects undergo somatic pairing, where homologous chromosomes closely pair up side by side throughout their length.