Genetics Practice Exam - FMG Fall 2024 - PDF

a condition caused by a combination of multiple genes and environmental factors....

a condition caused by a combination of multiple genes and environmental factors. Examples include heart disease, diabetes, and some types of cancer. These disorders don't come from just one gene mutation, but rather a complex interaction of several genes and external factors. Mitochondrial diseases are inherited through the mother because mitochondria (the energy- producing structures in cells) are passed down only through the egg cell, not the sperm. This means the mother’s mitochondrial DNA is inherited by all of her children, regardless of their single-gene disorders sex. (e.g., cystic brosis or sickle cell anemia) a condition caused by the combined e ects of Examples of Polygenic Disorders: Heart disease multiple genes rather Diabetes than a single gene Hypertension (high blood pressure) mutation. Alzheimer’s disease Schizophrenia Chromatin is the way DNA is Some cancers packaged inside a cell's nucleus. A nucleosome is the basic unit of chromatin structure. Nucleosomes help package and organize DNA within the nucleus, making it more compact and accessible for processes like replication and transcription. The 5' region of human genes contains promoters and enhancers, which are regulatory sequences that control gene expression. Promoters → Regions where RNA polymerase binds to start transcription. Enhancers → Sequences that boost gene transcription by interacting with transcription factors. RNA has a mRNA, rRNA, tRNA  A gene family is a group of genes that are similar because they come from a common ancestor gene. Gene families arise primarily Transcription is the process of making RNA through gene duplication, where from DNA, not a mechanism for creating gene a gene is copied within the families. genome Recombination can shu e gene sequences but does not create entirely new gene copies. -DNA that look like functional genes but don't actually work. They are often considered "broken" genes because they may have lost the ability to produce proteins, which is the usual job of a gene is a process where the activity of a gene is reduced or turned o. Normally, Think of it like a book that’s when a gene is "turned on," it gets read by the cell to make a protein. R supposed to be read out loud, but someone puts a lock on it so no one can read it -is a process where tiny chemical tags, called "methyl groups," attach to the DNA. These tags can a ect how genes work. When a methyl group is added to a gene, it can "turn o " that gene, stopping it from being used to make proteins. -instead of having the usual two copies of a gene (one from each parent), a person might have more or fewer copies of that gene or DNA segment In routine karyotyping, cells are arrested in metaphase because this is when chromosomes are most condensed and visible under a microscope. Chromosomal aneuploidy means having the Chromosomal nondisjunction is the wrong number of chromosomes in a cell. most common cause of chromosomal Normally, humans have 46 chromosomes, but in aneuploidy. It occurs when aneuploidy, a person may have too many or too chromosomes fail to separate properly few chromosomes. during cell division (either meiosis I or meiosis II). This results in one cell with an extra chromosome and one cell missing a chromosome.