Medical Genetics & Genomic Knowledge Flashcards

What is the function of a gene?

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.

Which of the following describes a mutation?

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.

What is the role of chromosomes in genetics?

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.

What does autosomal recessive inheritance mean?

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).

Which condition is commonly inherited in an autosomal dominant pattern?

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.

What is the human genome?

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.

Which organelle contains its own DNA?

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.

How many pairs of chromosomes are typically found in human cells?

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.

What is gene expression?

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.