Free CGC Medical Genetics & Genomic Knowledge Questions and Answers — Questions and Answers
Question 1: What is the function of a gene?
- Store calcium
- Regulate blood pressure
- Carry genetic instructions (Correct answer)
- Produce glucose
Correct answer: Carry genetic instructions
A gene is a fundamental unit of heredity that carries genetic instructions from parents to offspring. These instructions are encoded in DNA and dictate the synthesis of proteins or functional RNA molecules, which in turn control the development, function, and maintenance of an organism. Genes are essentially the blueprints for all cellular processes and traits.
Question 2: Which of the following describes a mutation?
- A protein made by the body
- A temporary fever
- A change in the DNA sequence (Correct answer)
- An immune response
Correct answer: A change in the DNA sequence
A mutation is defined as a change in the DNA sequence of an organism. These changes can range from a single nucleotide alteration to large-scale chromosomal rearrangements. Mutations can occur spontaneously or be induced by external factors, and they are the ultimate source of genetic variation, sometimes leading to disease or providing evolutionary advantage.
Question 3: What is the role of chromosomes in genetics?
- Store fat
- Regulate temperature
- Transmit DNA to new cells (Correct answer)
- Digest food
Correct answer: Transmit DNA to new cells
Chromosomes are thread-like structures located inside the nucleus of animal and plant cells, made of protein and a single molecule of DNA. Their primary role in genetics is to package and organize DNA, ensuring that genetic information is accurately transmitted to new cells during cell division and from one generation to the next. They carry the genes that determine an individual's traits.
Question 4: What does autosomal recessive inheritance mean?
- Only one copy of a gene causes disease
- Gene is located on a sex chromosome
- Two copies of a gene must be mutated (Correct answer)
- Only females are affected
Correct answer: Two copies of a gene must be mutated
Autosomal recessive inheritance means that an individual must inherit two copies of a mutated gene—one from each parent—to develop the associated disease. Individuals with only one mutated copy are typically carriers and do not show symptoms. The gene responsible is located on an autosome (a non-sex chromosome).
Question 5: Which condition is commonly inherited in an autosomal dominant pattern?
- Cystic fibrosis
- Marfan syndrome (Correct answer)
- Sickle cell anemia
- Phenylketonuria
Correct answer: Marfan syndrome
Marfan syndrome is a classic example of a condition inherited in an autosomal dominant pattern. This means that only one copy of the mutated gene (FBN1) is sufficient to cause the disorder. Affected individuals have a 50% chance of passing the condition to each of their children, regardless of the child's sex.
Question 6: What is the human genome?
- A medical textbook
- All the chromosomes in a human (Correct answer)
- A blood type classification
- An enzyme in digestion
Correct answer: All the chromosomes in a human
The human genome refers to the complete set of genetic instructions found in a human cell, encompassing all the DNA contained within the 23 pairs of chromosomes in the nucleus and the small circular DNA in the mitochondria. It contains all the information needed to build and maintain a human being. It is not a textbook, blood classification, or enzyme.
Question 7: Which organelle contains its own DNA?
- Ribosome
- Nucleus
- Mitochondrion (Correct answer)
- Endoplasmic reticulum
Correct answer: Mitochondrion
The mitochondrion is a unique organelle within eukaryotic cells that contains its own small, circular DNA molecule, separate from the nuclear DNA. This mitochondrial DNA (mtDNA) encodes for some proteins involved in cellular respiration and is inherited exclusively from the mother. The nucleus also contains DNA, but the question asks for an organelle that contains *its own* DNA, distinct from the main nuclear genome.
Question 8: How many pairs of chromosomes are typically found in human cells?
- 20
- 22
- 23 (Correct answer)
- 46
Correct answer: 23
Human cells typically contain 23 pairs of chromosomes, totaling 46 chromosomes. Of these, 22 pairs are autosomes (non-sex chromosomes), and one pair consists of sex chromosomes (XX for females, XY for males). This number is characteristic for the human species.
Question 9: What is gene expression?
- Gene duplication
- Turning genes into sugar
- Process of making protein from a gene (Correct answer)
- DNA packaging
Correct answer: Process of making protein from a gene
Gene expression is the fundamental process by which information from a gene is used in the synthesis of a functional gene product, such as a protein or a functional RNA molecule. This process involves transcription (DNA to RNA) and translation (RNA to protein), ultimately allowing the genetic instructions to manifest as observable traits or cellular functions.
Free CGC Medical Genetics & Genomic Knowledge Questions and Answers
What is the function of a gene?