Genes are individual segments of DNA and chromosomes are structures which contain many genes packed together. Each chromosome contains one DNA molecule and each DNA molecule contains several genes or individual strands.
A:Mitosis is important because it is essential for growth and repair in the body. Mitosis happens when a parent cell divides, creating two identical copies, referred to as daughter cells. During this process, it is essential that the daughter cells are exactly the same with the same copies of DNA.
A:Centrosomes are organelles responsible for the organization and nucleation of microtubules in animal cells and also regulate the cell cycle during cellular division. When the nuclear membrane breaks down during mitosis, the chromosomes interact with the centrosome nucleated microtubules to build the mitotic spindle. The centrosome plays a key role in efficient mitosis, but it is not considered essential.
A:Ethanol is used in DNA extraction to force the DNA to precipitate in a solution. In order to collect a DNA sample, cells are broken down through agitation, then mixed with water, salt and ethanol to create an aqueous solution. Ethanol and salt work to prevent the DNA from dissolving into the water, instead causing it to precipitate out so it can be separated and extracted using a centrifuge.
A:The lacZ gene is a gene present in E. coli that encodes the protein beta-galactosidase. Beta-galactosidase is an enzyme that is essential for the breakdown of lactose as it cleaves a bond between the two carbon rings in lactose to produce glucose and galactose.
A:Spermatozoa, also referred to as sperm, are male reproductive cells. Sperm occur in several different forms, and are essential components for reproduction. Sperm vary slightly in physical composition, but have distinct body shapes, characterized by heads and long singular tails.
A:Chromatin is made of nucleic acids, such as DNA or RNA, and proteins. During cell division, chromatin condenses to form chromosomes. Eukaryotic and prokaryotic cells differ in where chromatin is housed. In eukaryotes, it is located in the nucleus and in prokaryotes, it is located in the nucleoid.
A:DNA replicates to make copies of itself. This is an indispensable process that allows cells to divide for a living organism to grow or reproduce. Each new cell needs a DNA copy, which serves as instructions on how to function as a cell.
A:The simplest way to describe chromosome structure is as an X-shaped microscopic bit of genetic information that's part of DNA. However, this is not the only way that chromosomes can be structured, and new research that came out in 2013 calls the popularly accepted X-shape structure into question.
A:Catabolic pathways involve chemical reactions that convert complex organic molecules into simple substances, and they either store energy or release it as heat. Anabolic pathways involve chemical reactions that build novel molecules and make use of energy stored in the catabolic reactions.
A:The Hardy-Weinberg principle states that the genetic variation in a population stays constant over generations in the absence of disruptive factors. The concept predicts that when mating occurs randomly in a vast population, the allele and genotype frequencies remain consistent because they are in equilibrium.
A:Protein turnover refers to the degradation of proteins over time. It reflects the balance between a cells synthesis of protein and that proteins breakdown. This factor determines the concentration of a protein existing within a cell.
A:All carbohydrates are made from carbon, hydrogen and oxygen. They have twice as many hydrogen atoms as oxygen atoms. The word "carbohydrate" is a combination of the names of these elements and means "watered carbon." The presence of carbon makes carbohydrates organic, rather than inorganic, compounds.
A:The Golgi apparatus collects simple chemicals in the cell and assembles them into large, complex structures such as proteins. It also plays a role in the process of simple chemical secretion by forming closed vesicles around the substance to be transported. These vesicles then pinch off from the Golgi apparatus and drift to the cell's plasma membrane where the transported substance is released from the cell.
A:Nucleotides are held together by two types of bonds: phosphodiester bonds and hydrogen bonds. Education Portal describes phosphodiester bonds as bonds that link nucleotides into linear chains. According to Cambridge Physics, hydrogen bonds act as a bridge that connects two parallel rows of nucleotides. This connection aids in the formation of DNA's distinctive double-helix structure.
A:The NIH Genetics Home Reference Handbook explains that mutations are passed to offspring if these mutations are present in germ line (sperm or egg) cells. Germ line mutations can occur early in the parent's development so that they affect all of the cells in the parent's body, including eventual gametes. These mutations can also occur in gametes alone and therefore only affect offspring.
A:Gregor Mendel used pea plants in his research on heredity because they had characteristics that were consistent and easy to recognize. Pea plants had other qualities that also made them ideal for cross-pollination.
A:Criminal Justice Degree Schools define a crime laboratory analyst as a person who classifies and processes physical evidence gathered from crime scenes. His job is to help investigators determine methods used in crime and possible suspects on the basis of evidence.
A:Heredity refers to the passing of characteristics from parents to offspring. Genetics is the study of heredity, genes and variations in organisms. Heredity occurs in plants, animals, bacteria and fungi.