Q21. Which disorder is characterized by the inability to produce melanin?
a) Albinism
b) Hemophilia
c) Sickle cell anemia
d) Tay-Sachs disease
Show Answer
Correct Answer: a) Albinism
Explanation: Albinism is a group of inherited disorders characterized by little or no melanin production. Melanin is the pigment responsible for the color of the skin, hair, and eyes. People with albinism typically have light skin, white or pale hair, and visual problems.
Q22. What is the purpose of a genetic map?
a) To determine the exact location of genes on a chromosome
b) To show the sequence of proteins in a gene
c) To trace the inheritance patterns of traits
d) To compare the genomes of different species
Show Answer
Correct Answer: a) To determine the exact location of genes on a chromosome
Explanation: A genetic map, also known as a linkage map, is used to determine the position and relative distances between genes on a chromosome. These maps are crucial for understanding gene linkage and are used in various genetic research and testing.
Q23. What is the term for the complete loss of function in one copy of a gene?
a) Haploinsufficiency
b) Null mutation
c) Dominant negative mutation
d) Loss of heterozygosity
Show Answer
Correct Answer: a) Haploinsufficiency
Explanation: Haploinsufficiency occurs when a person has only one functional copy of a gene, and this single copy is not enough to support normal function. This can lead to diseases or disorders, especially if the gene is involved in critical functions or development.
Q24. What does ‘polygenic’ mean in genetics?
a) Caused by multiple genes
b) Caused by a single gene
c) Caused by a mutation in a gene
d) Caused by a deletion of a gene
Show Answer
Correct Answer: a) Caused by multiple genes
Explanation: Polygenic refers to a trait or disorder that is influenced by several genes. Polygenic traits do not follow simple Mendelian inheritance patterns and often show a continuous distribution, such as height or skin color in humans.
Q25. Which process describes the ‘reading’ of mRNA to build a protein?
a) Replication
b) Transcription
c) Translation
d) Mutation
Show Answer
Correct Answer: c) Translation
Explanation: Translation is the process in which the sequence of the mRNA molecule is ‘read’ by the ribosome and the corresponding amino acids are linked together to form a protein. It is the step following transcription in protein synthesis.
Q26. Which disorder results from the inheritance of a defective gene on the X chromosome in males?
a) Turner Syndrome
b) Klinefelter Syndrome
c) Color blindness
d) Cystic Fibrosis
Show Answer
Correct Answer: c) Color blindness
Explanation: Color blindness, particularly red-green color blindness, is an example of an X-linked disorder predominantly affecting males. Since males have only one X chromosome, the inheritance of a defective gene on this chromosome results in the manifestation of the disorder.
Q27. Which term refers to organisms that have two different alleles for a particular trait?
a) Homozygous
b) Heterozygous
c) Hemizygous
d) Homologous
Show Answer
Correct Answer: b) Heterozygous
Explanation: Heterozygous refers to having two different alleles for a specific trait. One allele is inherited from each parent. In a heterozygous genotype, the two alleles differ, which can result in varying dominance and recessiveness patterns for a particular trait.
Q28. What is the primary function of mRNA in the cell?
a) To replicate DNA
b) To repair DNA
c) To carry genetic information from DNA to the ribosome
d) To produce ribosomal subunits
Show Answer
Correct Answer: c) To carry genetic information from DNA to the ribosome
Explanation: The primary function of mRNA (messenger RNA) is to carry genetic information transcribed from DNA to the ribosome, where it can be translated into proteins. It acts as a messenger between the genetic information in the DNA and the protein synthesis machinery of the cell.
Q29. What is the significance of the Human Genome Project?
a) It was a project to create an artificial human genome
b) It discovered the structure of DNA
c) It was an international effort to map all the genes of the human genome
d) It was the first project to clone a human gene
Show Answer
Correct Answer: c) It was an international effort to map all the genes of the human genome
Explanation: The Human Genome Project was an international scientific research project with the goal of determining the base pairs that make up human DNA, and of identifying and mapping all of the genes of the human genome. It was a milestone in genetics and has had significant impacts on medicine, biotechnology, and the life sciences.
Q30. What causes Down Syndrome?
a) A mutation in the DNA sequence
b) Inheritance of a dominant gene
c) Trisomy of chromosome 21
d) Deficiency of a vital protein
Show Answer
Correct Answer: c) Trisomy of chromosome 21
Explanation: Down Syndrome is caused by trisomy of chromosome 21, which means that each cell in the body has three copies of chromosome 21 instead of the usual two copies. This extra genetic material affects the development and causes the characteristics associated with Down Syndrome.