Science

Saul G. (United States of America)
82 words 2 learners

Learn words with Flashcards and other activities

Definition First极速168赛车 377936e02ce27ce724b98272ce20c0e0
Print Flashcards极速168赛车 902a441ff479f3adacbe4135eb3a3334

Other learning activities

Answer a few questions about each word. Use this to prep for your next quiz! Compete with other teams in real time to see who answers the most questions correctly! Test your spelling acumen. Read the definition, listen to the word and try spelling it!

Teaching tools

Create and assign quizzes to your students to test their vocabulary. Assign learning activities including Practice, Vocabulary Jams and Spelling Bees to your students, and monitor their progress in real-time.

Full list of words from this list:

words only definitions & notes
  1. dominant allele
    an allele that produces the same phenotype whether its paired allele is identical or different
    The Nature of Alleles

    A dominant allele is an allele that is almost always expressed, even if only one copy is present.
  2. recessive allele
    an allele that produces its characteristic phenotype only when its paired allele is identical
    On the other hand, a recessive allele will be expressed only if there are two identical copies of that allele, or for a male, if one copy is present on the X chromosome.
  3. organelle
    a specialized part of a cell; analogous to an organ
    Organelle DNA

    Not all genetic information is found in nuclear DNA.
  4. coding DNA
    sequence of a gene's DNA that transcribes into protein structures
    Another class of non-coding DNA is the "pseudogene", so named because it is believed to be a remnant of a real gene that has suffered mutations and is no longer functional.
  5. linked genes
    any pair of genes that tend to be transmitted together
    There are at least a dozen Y-linked genes, in addition to those that code for masculine physical traits.
  6. mitochondrion
    part of a cell involved in energy production
    Both plants and animals have an organelle-a "little organ" within the cell- called the mitochondrion.
  7. eukaryote
    an organism of one or more cells with membrane-bound nuclei
    The location and base sequence of each promoter site vary for prokaryotes (bacteria) and eukaryotes (higher organisms), but they are both recognized by RNA polymerase, which can then grab hold of the sequence and drive the production of an mRNA.
  8. mRNA
    the template for protein synthesis
    Ribonucleic Acids
    In addition to mRNA, DNA codes for other forms of RNA, including ribosomal RNAs (rRNAs), transfer RNAs (tRNAs), and small nuclear RNAs (snRNAs). rRNAs and tRNAs participate in protein assembly whereas snRNAs aid in a process called splicing -the process of editing of mRNA before it can be used as a template for protein synthesis.
  9. allele
    any of the forms of a gene that can occupy the same locus
    Methylation also plays an important role in genomic imprinting, which occurs when both maternal and paternal alleles are present but only one allele is expressed while the other remains inactive.
  10. RNA polymerase
    the enzyme that copies DNA into RNA
    Transcription

    Transcription, the synthesis of an RNA copy from a sequence of DNA, is carried out by an enzyme called RNA polymerase.
  11. phenotype
    observable characteristics produced by genes and environment
    When two individuals display different phenotypes of the same trait, they are said to have two different alleles for the same gene.
  12. ribosome
    a particle in a cell that helps synthesize proteins
    Because mitochondria have their own DNA, RNA, and ribosomes, this scenario is quite possible.
  13. phenotypic
    of or relating to or constituting a phenotype
    These expressed, or phenotypic, traits are attributable to genotypic variation in a person's DNA sequence.
  14. genotypic
    of or relating to or constituting a genotype
    These expressed, or phenotypic, traits are attributable to genotypic variation in a person's DNA sequence.
  15. polymerase
    an enzyme that catalyzes the formation of new DNA and RNA from an existing strand of DNA or RNA
    Transcription

    Transcription, the synthesis of an RNA copy from a sequence of DNA, is carried out by an enzyme called RNA polymerase.
  16. meiosis
    cell division that produces reproductive cells
    Meiosis is the mode of cell replication for the formation of sperm and egg cells in plants, animals, and many other multicellular life forms.
  17. deoxyribose
    a sugar that is a constituent of nucleic acids
    In a DNA chain, every base is attached to a sugar molecule (deoxyribose) and a phosphate molecule, resulting in a nucleic acid or nucleotide.
  18. eukaryotic
    having cells with `good' or membrane-bound nuclei
    This theory is also supported by the existence of a eukaryotic organism, called the amoeba, which lacks mitochondria.
  19. gamete
    a mature sexual reproductive cell
    This is because mitochondria are only found in the female gametes or "eggs" of sexually reproducing animals, not in the male gamete, or sperm.
  20. nucleotide
    a phosphoric ester of a nucleoside
    In a DNA chain, every base is attached to a sugar molecule (deoxyribose) and a phosphate molecule, resulting in a nucleic acid or nucleotide.
  21. amino acid
    organic compounds containing an amino group and acid group
    Proteins are long chains containing as many as 20 different kinds of amino acids.
  22. chromosome
    a threadlike strand of DNA that carries genes
    In 1909, Danish botanist Wilhelm Johanssen coined the word gene for the hereditary unit found on a chromosome.
  23. mosaicism
    the condition in which an organism has two or more cell populations that differ in genetic makeup
    In this case, somatic mosaicism may be the culprit.
  24. RNA
    a nucleic acid that helps synthesize proteins and transmit genetic data
    Because mitochondria have their own DNA, RNA, and ribosomes, this scenario is quite possible.
  25. somatic cell
    a cell that does not participate in reproduction
    Mutations that occur in somatic cells-any cell in the body except gametes and their precursors-will not be passed on to the next generation.
  26. cytosine
    a base found in DNA and RNA and derived from pyrimidine
    A DNA chain is made up of four chemical bases: adenine (A) and guanine (G), which are called purines, and cytosine (C) and thymine (T), referred to as pyrimidines.
  27. diploid
    an organism or cell having the normal amount of DNA per cell
    The term diploid describes a state in which a cell has two sets of homologous chromosomes, or two chromosomes that are the same.
  28. X chromosome
    the sex chromosome that is present in both sexes: singly in males and doubly in females
    There are numerous forms of this "repetitive DNA", and a few have known functions, such as stabilizing the chromosome structure or inactivating one of the two X chromosomes in developing females, a process called X-inactivation.
  29. ribose
    a pentose sugar important as a component of ribonucleic acid
    However, the ribose sugar component of RNA is slightly different chemically than that of DNA.
  30. repressor
    an agent that represses
    Other regulatory sequences include activators, repressors, and enhancers.
  31. gene
    part of DNA controlling physical characteristics and growth
    The biological information contained in a genome is encoded in its deoxyribonucleic acid (DNA) and is divided into discrete units called genes.
  32. base pair
    one of the pairs of chemical bases joined by hydrogen bonds that connect the complementary strands of a DNA molecule or of an RNA molecule that has two strands; the base pairs are adenine with thymine and guanine with cytosine in DNA and adenine with uracil and guanine with cytosine in RNA
    Thus, A-T and G-C base pairs are said to be complementary.
  33. guanine
    a purine base found in DNA and RNA; pairs with cytosine
    A DNA chain is made up of four chemical bases: adenine (A) and guanine (G), which are called purines, and cytosine (C) and thymine (T), referred to as pyrimidines.
  34. centromere
    a specialized condensed region of each chromosome that appears during mitosis where the chromatids are held together to form an X shape
    The centromere, shown at the center of this chromosome, is a specialized structure that appears during cell division and ensures the correct distribution of duplicated chromosomes to daughter cells.
  35. recessive
    of or pertaining to a recession
    These factors each exhibit a characteristic dominant, co-dominant, or recessive expression, and those that are dominant will mask the expression of those that are recessive.
  36. gene expression
    conversion of the information encoded in a gene first into messenger RNA and then to a protein
    Genes code for proteins that attach to the genome at the appropriate positions and switch on a series of reactions called gene expression.
  37. serine
    a sweetish crystalline amino acid involved in the synthesis by the body of cysteine
    For example, the amino acid serine is encoded by UCU, UCC, UCA, and/or UCG.
  38. homozygous
    having identical alleles at corresponding chromosomal loci
    If both alleles are the same, the gene is said to be homozygous.
  39. DNA
    material that carries genetic information in a cell
    The biological information contained in a genome is encoded in its deoxyribonucleic acid (DNA) and is divided into discrete units called genes.
  40. telomere
    either (free) end of a eukaryotic chromosome
    These sequences are associated with chromosome structure and are found at the centromeres (or centers) and telomeres (ends) of chromosomes.
  41. dominant gene
    gene that produces the same phenotype in the organism whether or not its allele identical
    Just how the dominant allele overshadows the other allele depends on the gene, but in some cases the dominant gene produces a gene product that the other allele does not.
  42. adenine
    purine base found in DNA and RNA
    A DNA chain is made up of four chemical bases: adenine (A) and guanine (G), which are called purines, and cytosine (C) and thymine (T), referred to as pyrimidines.
  43. chloroplast
    organelle in which photosynthesis takes place
    Plants also have a second organelle, the chloroplast, which also has its own DNA.
  44. achondroplasia
    an inherited skeletal disorder beginning before birth
    Well-known dominant alleles occur in the human genes for Huntington disease, a form of dwarfism called achondroplasia, and polydactylism (extra fingers and toes).
  45. type B
    the blood group whose red cells carry the B antigen
    So, the possible allele combinations result in a particular blood type in this way:
    OO = blood type O
    AO = blood type A
    BO = blood type B
    AB = blood type AB
    AA = blood type A
    BB = blood type B

    You can see that a person with blood type B may have a B and an O allele, or they may have two B alleles.
  46. adenosine triphosphate
    a nucleotide derived from adenosine that occurs in muscle tissue; the major source of energy for cellular reactions
    This is because mitochondria are responsible for converting the energy stored in macromolecules into a form usable by the cell, namely, the adenosine triphosphate (ATP) molecule.
  47. haploid
    (genetics) an organism or cell having only one complete set of chromosomes
    Hence, gametes are said to be haploid-having only a single set of homologous chromosomes.
  48. junk DNA
    stretches of DNA that do not code for genes
    Structural Genes, Junk DNA, and Regulatory Sequences
    Over 98 percent of the genome is of unknown function.
  49. recombination
    the rearrangement of genes (by crossing over) in offspring
    It is still unclear what all the functions of introns are, but scientists believe that some serve as the site for recombination, the process by which progeny derive a combination of genes different from that of either parent, resulting in novel genes with new combinations of exons, the key to evolution.
  50. genetic code
    the ordering of nucleotides in DNA molecules that carries the genetic information in living cells
    The genetic code carried by DNA is what specifies the order and number of amino acids and, therefore, the shape and function of the protein.
  51. protein
    an organic compound essential to living cells
    Genes code for proteins that attach to the genome at the appropriate positions and switch on a series of reactions called gene expression.
  52. exon
    sequence of a gene's DNA that transcribes into protein structures
    The Core Gene Sequence: Introns and Exons

    Genes make up about 1 percent of the total DNA in our genome.
  53. genome
    the full DNA sequence of an organism
    WHAT IS A GENOME?
  54. coding
    act of writing in code or cipher
    In the human genome, the coding portions of a gene, called exons, are interrupted by intervening sequences, called introns.
  55. purine
    a colorless crystalline organic base containing nitrogen
    A DNA chain is made up of four chemical bases: adenine (A) and guanine (G), which are called purines, and cytosine (C) and thymine (T), referred to as pyrimidines.
  56. messenger RNA
    the template for protein synthesis
    For example, all genes that code for proteins are first made into an RNA strand in the nucleus called a messenger RNA (mRNA).
  57. ribonucleic acid
    a nucleic acid that helps synthesize proteins and transmit genetic data
    Just like DNA, ribonucleic acid (RNA) is a chain, or polymer, of nucleotides with the same 5' to 3' direction of its strands.
  58. transcription
    something written, copied from one medium to another
    Transferring the code from DNA to RNA is a fairly straightforward process called transcription.
  59. protein molecule
    any large molecule containing chains of amino acids linked by peptide bonds
    They perform such functions as transporting nutrients into the cell; synthesizing new DNA, RNA, and protein molecules; and transmitting chemical signals from outside to inside the cell, as well as throughout the cell-both critical to the process of making proteins.
  60. polymorphic
    having or occurring in several distinct forms
    This means that the gene's sequence is slightly different in the two individuals, and the gene is said to be polymorphic, "poly" meaning many and "morph" meaning shape or form.
  61. heme
    a complex red organic pigment containing iron and other atoms to which oxygen binds
    Globin is the protein that complexes with the iron-containing heme molecule to make hemoglobin.
  62. mitosis
    the process by which a cell divides into two new cells
    Cells that compose tissues in multicellular organisms typically replicate by organized duplication and spatial separation of their cellular genetic material, a process called mitosis.
  63. hydroxyl group
    the monovalent group -OH in such compounds as bases and some acids and alcohols
    The so-called 5' end terminates in a 5' phosphate group (-PO4); the 3' end terminates in a 3' hydroxyl group (-OH).
  64. adenosine
    a nucleoside that is a structural component of nucleic acids
    This is because mitochondria are responsible for converting the energy stored in macromolecules into a form usable by the cell, namely, the adenosine triphosphate (ATP) molecule.
  65. cell
    the basic structural and functional unit of all organisms
    Genes instruct each cell type- such as skin, brain, and liver-to make discrete sets of proteins at just the right times, and it is through this specificity that unique organisms arise.
  66. hemoglobin
    a red protein in blood that transports oxygen
    Globin is the protein that complexes with the iron-containing heme molecule to make hemoglobin.
  67. enzyme
    a complex protein produced by cells that acts as a catalyst
    Each cell contains thousands of different proteins: enzymes that make new molecules and catalyze nearly all chemical processes in cells; structural components that give cells their shape and help them move; hormones that transmit signals throughout the body; antibodies that recognize foreign molecules; and transport molecules that carry oxygen.
  68. genetic mutation
    any event that changes genetic structure
    Genetic mutations occur randomly, and the effect of a small number of mutations on a single gene may be minimal.
  69. cytoplasm
    the substance inside a cell, not including the nucleus
    The mRNA carries the information encoded in DNA out of the nucleus to the protein assembly machinery, called the ribosome, in the cytoplasm.
  70. duplex
    a house with two units sharing a common wall
    Recombination involves pairing between complementary strands of two parental duplex DNAs (top and middle panel).
  71. polymer
    a naturally occurring or synthetic compound
    Just like DNA, ribonucleic acid (RNA) is a chain, or polymer, of nucleotides with the same 5' to 3' direction of its strands.
  72. beta
    the second letter of the Greek alphabet
    To further complicate matters, globin is made from two different protein chains: an alpha-like chain coded for on chromosome 16; and a beta-like chain coded for on chromosome 11.
  73. methyl
    the univalent radical CH3- derived from methane
    One chemical modification of DNA, called methylation, involves the addition of a methyl group (-CH3).
  74. decode
    convert something hidden or secretive into ordinary language
    Here the mRNA is translated into protein by decoding the mRNA sequence in blocks of three RNA bases, called codons, where each codon specifies a particular amino acid.
  75. phosphate
    a salt of phosphoric acid
    In a DNA chain, every base is attached to a sugar molecule (deoxyribose) and a phosphate molecule, resulting in a nucleic acid or nucleotide.
  76. antibody
    a protein that produces an immune response
    Each cell contains thousands of different proteins: enzymes that make new molecules and catalyze nearly all chemical processes in cells; structural components that give cells their shape and help them move; hormones that transmit signals throughout the body; antibodies that recognize foreign molecules; and transport molecules that carry oxygen.
  77. ATP
    a nucleotide derived from adenosine that occurs in muscle tissue; the major source of energy for cellular reactions
    This is because mitochondria are responsible for converting the energy stored in macromolecules into a form usable by the cell, namely, the adenosine triphosphate (ATP) molecule.
  78. viral
    relating to or caused by a virus
    For example, some viral genes are known to have high mutation rates.
  79. theory of evolution
    (biology) a scientific theory of the origin of species of plants and animals
    Mutations are what lie behind the popular saying of "survival of the fittest", the basic theory of evolution proposed by Charles Darwin in 1859.
  80. immune system
    the cells in the body that work together to fight disease
    Mutations serve the virus well by enabling adaptive traits, such as changes in the outer protein coat so that it can escape detection and thereby destruction by the host's immune system.
  81. precursor
    something indicating the approach of something or someone
    Mutations that occur in somatic cells-any cell in the body except gametes and their precursors-will not be passed on to the next generation.
  82. feedback
    the process in which output of a system is returned to input
    At other levels, cells regulate gene expression through DNA folding, chemical modification of the nucleotide bases, and intricate "feedback mechanisms" in which some of the gene's own protein product directs the cell to cease further protein production.
Created on 五月 28, 2011

Sign up now (it’s free!)

Whether you’re a teacher or a learner 全国统一开奖网址, soonshin.com can put you or your class on the path to systematic vocabulary improvement.