Biology

Molecular Biology and Genetics

717 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 zoology molecular basis of inheritance genome projects human genome project human genome project and dna fingerprinting

Lily has .......... more DNA than human genome.

  1. 10 times

  2. 4 times

  3. 20 times

  4. 18 times
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The main aim of the Human Genome Project was to determine the sequence of 3.2 billion base pairs of Human Genome and to identify their functions.

It was found that Human Genome contains around 30,000 jeans and 99.9% of nucleotide bases and all human beings are same.
The amount of genes present in Lily is 18 times more than the Human Genome.

So, the correct option is '18times'.

Multiple choice zoology molecular basis of inheritance genome projects human genome project human genome project and dna fingerprinting

Human genome contains base pairs

  1. 2.5 million

  2. 25 million

  3. 27.2 million

  4. 3.2 billion
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

There are four bases adenine (A), thymine (T), guanine (G) and cytosine (C) present in humans. Bases on opposite strands pair specifically as an A always pairs with a T, and a C always with a G. The human genome contains approximately 3.2 billion of these base pairs, which reside in the 23 pairs of chromosomes within the nucleus of all our cells.

So, the correct option is '3.2 billion'.

Multiple choice zoology molecular basis of inheritance genome projects human genome project human genome project and dna fingerprinting

A ribotide is made of

  1. Adenine + Deoxyribose + Phosphate

  2. Uracil + Ribose + Phosphate

  3. Thymine + Ribose + Phosphate

  4. Uracil + Deoxyribose + Phosphate
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A ribotide (ribonucleotide) consists of a nitrogenous base (like Uracil in RNA), a ribose sugar, and a phosphate group. Deoxyribose is found in DNA, not RNA.

Multiple choice zoology molecular basis of inheritance genome projects human genome project human genome project and dna fingerprinting

Which ones are degenerate codons ?

  1. UAA, UAG and UGA

  2. GUA, GUG, GCA, GCG and GAA

  3. UUC, UUG, CCU, CAA and CUA

  4. UUA, UUG, CUU, CUC, CUA and CUG

  5. AAC, AAG, GAC and CGG
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Degeneracy means that multiple codons can code for the same amino acid. The set UUA, UUG, CUU, CUC, CUA, and CUG all code for the amino acid Leucine.

Multiple choice zoology molecular basis of inheritance genome projects human genome project human genome project and dna fingerprinting

As per latest information human genome has

  1. $3,00,000$ genes
  2. $20,000$ genes
  3. $3,000$ genes
  4. $300$ genes
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
There are an estimated 19,000-20,000 human protein-coding genes. The estimate of the number of human genes has been repeatedly revised down from initial predictions of 100,000 or more as genome sequence quality and gene finding methods have improved and could continue to drop further.
So, the correct answer is '20,000 genes'.
Multiple choice zoology molecular basis of inheritance genome projects human genome project human genome project and dna fingerprinting

The human genome contains (a) billion nucleotide bases. The average gene consists of (b) bases. Which option is correct for a & b?

  1. $a = 3, b = 3000$
  2. $a = 5, b = 3000$
  3. $a = 3, b = 2000$
  4. $a = 4, b = 3000$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The human genome contains approximately 3 billion base pairs, and the average gene size is estimated to be around 3000 base pairs.

Multiple choice bio-chemistry nucleic acids central dogma transcription and gene expression molecular biology

Find out the correct answers out of the following discoveries
1. Griffith-Transformation
2. Gamow-Triplet code
3. Miescher-Nucieic acid

  1. 1, 2 and 3 correct

  2. 1 and 2 correct, 3 false

  3. 1 correct, 2 and 3 false

  4. 1 and 3 correct, 2 false
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Griffith discovered transformation, Gamow proposed the triplet nature of the genetic code, and Miescher first isolated nucleic acids (nuclein). All are correct.

Multiple choice bio-chemistry nucleic acids central dogma transcription and gene expression molecular biology

In a 3.2K bp long piece of DNA, 820 adenine bases were found. What would be the number of cytosine bases

  1. 1480

  2. 740

  3. 560

  4. 780
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In double-stranded DNA, A pairs with T and G pairs with C. If there are 820 adenine bases, there must be 820 thymine bases, totaling 1640 bases. The remaining bases are 3200 - 1640 = 1560, which are split equally between G and C, so 1560 / 2 = 780 cytosine bases.

Multiple choice bio-chemistry nucleic acids central dogma transcription and gene expression molecular biology

Teminism is

  1. Central dogma reverse

  2. Central dogma of molecular biology

  3. Circular flow of hereditary information

  4. Effect of cytoplasm on functioning of DNA
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Teminism refers to the reverse of the central dogma - the flow of information from RNA back to DNA via reverse transcription. Howard Temin's work on retroviruses showed that the dogma was not unidirectional. Option B is the standard central dogma, C refers to something else, and D is unrelated.