"A chromosome is a long DNA molecule with part or all of the genetic material of an organism."
The structure and function of chromosomes, genes, and DNA as the genetic material that carries the instructions for the development and functioning of organisms.
DNA Structure: Understanding the structure of the molecule that makes up genetic material.
DNA Replication: Understanding the process of copying genetic material during cell division.
Gene Expression: Understanding how genetic information is used to produce proteins that determine the traits of an organism.
Mendelian Genetics: Understanding the basic principles of inheritance, including dominant and recessive traits.
Chromosome Structure: Understanding the organization of genetic material into chromosomes.
Genetic Variation: Understanding the different ways in which genetic information can vary within a population.
Genetic Mapping: Understanding the process of identifying the location of specific genes on a chromosome.
Genetic Engineering: Understanding the process of modifying genetic material for practical applications.
Human Genetics: Understanding the genetics of human traits, including health and disease.
Evolutionary Genetics: Understanding the role of genetic variation in evolutionary processes.
DNA (Deoxyribonucleic acid): The majority of genetic material in most organisms is DNA. It is composed of four bases: Adenine, Guanine, Thymine, and Cytosine. DNA is responsible for carrying genetic information from one generation to the next.
RNA (Ribonucleic acid): RNA is a single-stranded nucleic acid that contains the nitrogenous bases Adenine, Guanine, Cytosine, and Uracil. RNA plays a vital role in protein synthesis by carrying genetic information from DNA to ribosomes.
Mitochondrial DNA: Mitochondrial DNA is found in the mitochondria of cells and is inherited solely from the mother in most organisms. It plays an essential role in energy production within cells.
Autosomal chromosomes: Humans have 22 pairs of autosomes, which are not sex chromosomes. These chromosomes are responsible for carrying genetic information that determines various traits, such as eye color or height.
Sex chromosomes: Humans have one pair of sex chromosomes, with males having XY and females having XX. These chromosomes are responsible for determining an individual's sex.
Telocentric chromosomes: These chromosomes have a single centromere located at the end, giving them a "T" shape.
Acrocentric chromosomes: These chromosomes have a centromere near one end, causing them to have one long arm and one short arm.
Metacentric chromosomes: These chromosomes have a centromere located near the center, resulting in two equal arms of the chromosome.
Submetacentric chromosomes: These chromosomes have a centromere located near the center, resulting in one short arm and one long arm.
"In most chromosomes, the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells, the most important of these proteins are the histones."
"These proteins, aided by chaperone proteins, bind to and condense the DNA molecule to maintain its integrity."
"These chromosomes display a complex three-dimensional structure, which plays a significant role in transcriptional regulation."
"Chromosomes are normally visible under a light microscope only during the metaphase of cell division."
"Before this happens, each chromosome is duplicated (S phase), and both copies are joined by a centromere."
"The joined copies are now called sister chromatids."
"During metaphase, the X-shaped structure is called a metaphase chromosome, which is highly condensed and thus easiest to distinguish and study."
"In animal cells, chromosomes reach their highest compaction level in anaphase during chromosome segregation."
"Chromosomal recombination during meiosis and subsequent sexual reproduction play a significant role in genetic diversity."
"If these structures are manipulated incorrectly, through processes known as chromosomal instability and translocation, the cell may undergo mitotic catastrophe."
"Usually, this will make the cell initiate apoptosis leading to its own death."
"But sometimes mutations in the cell hamper this process and thus cause the progression of cancer."
"Some use the term chromosome in a wider sense, to refer to the individualized portions of chromatin in cells, either visible or not under light microscopy."
"Others use the concept in a narrower sense, to refer to the individualized portions of chromatin during cell division, visible under light microscopy due to high condensation."
"These packaging proteins... bind to and condense the DNA molecule to maintain its integrity."
"in eukaryotic cells, the most important of these proteins are the histones."
"The joined copies are now called sister chromatids."
"In animal cells, chromosomes reach their highest compaction level in anaphase during chromosome segregation."
"If these structures are manipulated incorrectly... the cell may undergo mitotic catastrophe."