Molecular Biology & DNA

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Chromatin and chromosomes are both structures of DNA, but chromosomes are condensed chromatin. DNA exists as chromatin a majority of the time so that the DNA is accessible to proteins for transcription and proteins can be made during the process of translation. Chromatin is condensed into chromosomes during mitosis to ensure that replicated genetic information is divided equally between the two resulting daughter cells.

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  • Does baldness come from your mother's father?

    Q: Does baldness come from your mother's father?

    A: Some scientists have concluded that male pattern baldness is handed down via a faulty gene through the male's maternal line. In other words, a man can get an idea of how his hair loss is likely to proceed from the appearance of men in his mother's family. The suspicious gene is in the X chromosome, which men inherit from their mothers.
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  • How rare are gray eyes?

    Q: How rare are gray eyes?

    A: After green eyes, gray and silver eye color are among the rarer shades. The only eye colors more rare in humans are the honey-gold amber eye color and red eyes.
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  • What is RNA primase?

    Q: What is RNA primase?

    A: According to Scitable, RNA primase is an enzyme involved in the replication of DNA strands during cell division. It goes over a single DNA strand and creates RNA sequences called primers, which transcribe DNA into RNA. These short sequences of RNA are complementary to the DNA strand they were hovering over, and serve as a template for a new strand of DNA.
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  • What is the chemical composition of carbohydrates?

    Q: What is the chemical composition of carbohydrates?

    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.
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  • What is the Hardy-Weinberg principle?

    Q: What is the Hardy-Weinberg principle?

    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.
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  • What is spermatozoa?

    Q: What is spermatozoa?

    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.
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  • How does DNA determine the traits of an organism?

    Q: How does DNA determine the traits of an organism?

    A: The pattern of base pairs in the DNA double helix encodes the instructions for building the proteins necessary to construct an entire organism. DNA, or deoxyribonucleic acid, is found within most cells of an organism, and most organisms have their own unique DNA code. One exception to this is cloned organisms, which have the same exact DNA code as their parents do.
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  • What happens during protein synthesis?

    Q: What happens during protein synthesis?

    A: Protein synthesis is the process of converting the DNA sequence to a sequence of amino acids to form a specific protein. It involves three main steps: transcription of mRNA from the DNA sequence, initiation of the translation of the mRNA sequence to an amino acid sequence and elongation of the protein chain as the mRNA codes for additional amino acids to be added to the growing chain.
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  • Why did Gregor Mendel use pea plants in his research?

    Q: Why did Gregor Mendel use pea plants in his research?

    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.
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  • Are freckles hereditary?

    Q: Are freckles hereditary?

    A: Freckles can be related to a dominant receptor gene for melanocortin-1, but they can also be the result of skin that is more sensitive to light. The skin cells that produce the pigment melanin are called melanocytes. They will produce melanin to protect the skin from sun damage, and when that pigment is transferred to the cells that make up the outer layer of skin, it shows as freckles.
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  • How are mutations passed on to offspring?

    Q: How are mutations passed on to offspring?

    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.
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  • Why must DNA be able to make copies of itself?

    Q: Why must DNA be able to make copies of itself?

    A: The University of Illinois at Chicago explains that DNA must replicate itself so that during cell division, both daughter cells receive the same genetic information. DNA replication is necessary during the process by which somatic cells divide, called mitosis, as well as during meiosis, the process by which organisms produce gametes, or sex cells.
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  • Why does DNA need to replicate?

    Q: Why does DNA need to replicate?

    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.
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  • Why did Mendel choose peas for his experiments?

    Q: Why did Mendel choose peas for his experiments?

    A: Gregor Mendel, a monk and teacher from Central Europe, chose common garden peas, or Pisum sativum, for his experiments in genetics because peas are easily grown in numbers large enough to be useful for his experiments and their reproduction can be altered. Pollen could be transferred from one pea flower to another with a paintbrush.
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  • What is a crime laboratory analyst?

    Q: What is a crime laboratory analyst?

    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.
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  • What do hox genes do?

    Q: What do hox genes do?

    A: Hox genes control the development of an organism. Specifically, they are a set of transcription factor genes that determine the anterior-posterior axis and the segments of an organism's body.
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  • What holds the nucleotides in one strand of DNA together?

    Q: What holds the nucleotides in one strand of DNA together?

    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.
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  • What makes up the backbone of the DNA molecule?

    Q: What makes up the backbone of the DNA molecule?

    A: Two components make the backbone in DNA, being the deoxy-ribose and phosphate molecules. These molecules link together in a staggered pattern where the deoxy-ribose and phosphate molecules follow one another, like the backbone of a zipper. Deoxy-ribose is a type of sugar molecule where the adenine, guanine, cytosine and thymine molecules attach a covalent bond. The phosphate molecules bond with the deoxy-ribose molecule acting like anchors in DNA.
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  • What makes up the rungs of the DNA molecule?

    Q: What makes up the rungs of the DNA molecule?

    A: As shown on the NIH Genetics Home Reference site, when DNA molecules are represented as ladders, the rungs represent the base pairs of the DNA. The bases in DNA are often represented as G, A, T and C, which stand for guanine, adenine, thymine and cytosine. When two strands of DNA form a double-strand helix, the bases pair up in the middle of the molecule.
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  • What is genetic splicing?

    Q: What is genetic splicing?

    A: Genetic splicing is the process in which an organism's DNA is cut and another gene is added. It is used so single-celled organisms can produce certain products, such as insulin, and produces genetically altered organisms.
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  • What is the difference between heredity and genetics?

    Q: What is the difference between heredity and genetics?

    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.
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