Genetics 1-7

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Genetics 1-7
2011-05-09 17:43:52
genetics vocab

genetics vocab ch. 1 - 7
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  1. Genetics
    The scientific study of heredity
  2. Trait
    Any observable property of an organism
  3. Gene
    • The fundamental unit of heredity and the basic structural and functional unit of genetics
    • -composed of DNA
    • -direct the formation of proteins
  4. DNA
    A helical molecule consisting of two strands of nucleotides that is the primary carrier of genetic informationDeoxyribose Nucleotide subunitsAdenine, thymine, guanine, or Cytosine
  5. Transmission genetics
    the branch of genetics concerned with the mechanisms by which genes are transferred from parent to offspring
  6. Pedigree analysis
    the construction of family trees and their use to follow the transmission of genetic traits in humans
  7. cytogenetics
    the branch of genetics that studies the organization and arrangement of genes and chromosomes by using the techniques of microscopy
  8. Karyotype
    a complete set of chromosomes from a cell that has been photographed during cell division and arranged in a standard sequence (chart arranged in order of size and centromere position)
  9. molecular genetics
    the study of genetic events at the biochemical level-uses recombinant DNA technology to identify, isolate, clone, and analyze genes-tremendous impact in last 40 years-debate over social, legal, and ethical issues
  10. recombinant DNA technology
    a series of techniques in which DNA fragments from an organism are linked to self-replicating vectors to create recombinant DNA molecules, which are replicated or cloned in a host cell
  11. Clones
    genetically identical molecules, cells, or organisms, all derived from a single ancestor
  12. Genome
    the set of DNA sequences carried my an individual (all the genes present in an organism plut other DNA sequences that do not encode genes)
  13. genomics
    the study of the organization, function, and evolution of genomes
  14. Gene therapy
    procedure in which normal genes are transplanted into humans carrying defective copies, as a means of treating genetic diseases
  15. population genetics
    the branch of genetics that studies inherited variation in populations of individuals and the forces that alter gene frequency
  16. eugenics
    the attempt to improve the human species by selective breeding
  17. hereditarianism
    the mistaken idea that human traits are determined solely by genetic inheritance, ignoring the contribution of the environment
  18. Single nucleotide polymorphism (SNP)
    single nucleotide differences between and among individuals in a population or species
  19. Haplotype
    a set of genetic markers located close together on a single chromosome or chromosome region
  20. Genome-wide association study
    Analysis of genetic variation across an entire genome searching for associations (linkages) between variations in DNA sequence and a genome region encoding a specific phenotype
  21. Biotechnology
    The use of recombinant DNA technology to produce commercial goods and services
  22. macromolecules
    large cellular polymers assembled by chemically linking monomers together
  23. Carbohydrates
    macromolecules including sugars, glycogen, and starches composed of sugar monomers linked and cross-linked (energy)
  24. Lipids
    A class of cellular macromolecules including fats and oils that are insoluble in water (membranes)
  25. Proteins
    A class of cellular macromolecules composed of amino acid monomers linked together and folded into a three-dimensional shape (structures & enzymes)
  26. Nucleic Acids
    A class of cellular macromolecules composed of nucleotide monomers linked together. there are two types- DNA and RNA, which differ in the structure of the monomers (genetic materials)
  27. molecules
    structures composed of two or more atoms held together by chemical bonds
  28. organelles
    cytoplasmic structures that have a specialized function
  29. Endoplasmic Reticulum
    a system of cytoplasmic membranes arranged into sheets and channels whose function it is to synthesize and transport gene products
  30. ribosomes
    Cytoplasmic particles that aid in the production of proteins
  31. golgi complex
    Membranous organelles composed of a series of flattened sacs. They sort, modify, and package proteins synthesized in the ER-final protein folding; stores secreted material; forms sugars, glycoproteins and glycolipids; vesicles of material are released
  32. Lysosomes
    Membrane-enclosed organelles in eukaryotic cells that contain digestive enzymes (Tay-sacs = lysosome disorder)
  33. Mitochondria
    membrane-bound organelles, present in the cytoplasm of all eukaryotic cells, that are the sites of energy (ATP) production-has its own circular DNA, inherited from mother
  34. Nucleus
    The (double-layered nuclear membrane) membrane-bound organelle in eukaryotic cells that contains the chromosomes
  35. nucleolus
    a nuclear region that functions in the synthesis of ribosomes
  36. chromatin
    The DNA and protein components of chromosomes, visible as clumps or threads in nuclei
  37. Chromosomes
    the threadlike structures in the nucleus that carry genetic information
  38. sex chromosomes
    in humans, the X and Y chromosomes that are involved in sex determination
  39. Autosomes
    Chromosomes other than the sex chromosomes. In humans, chromosomes 1-22 are autosomes
  40. cell cycle
    the sequence of events that takes place between successive mitotic divisions
  41. Interphase
    the period of time in the cell cycle between mitotic divisions-prepare for cell division; replicates DNA; composed of G1, S, G2; Cells may progress to mitosis or enter G0; quiescent phase
  42. mitosis
    form of cell division that produces two cells, each of which has the same complement of chromosomes as the parent cell
  43. cytokinesis
    the process of cytoplasmic division that accompanies cell division
  44. Prophase
    A stage in mitosis during which the chromosomes become visible and contain sister chromatids joined at the centromere
  45. Centromere
    a region of a chromosome to which spindle fibers attach during cell division. the location of a centromere gives a chromosome its characteristic shape
  46. sister chromatids
    Two chromatids joined by a common centromere. each chromatid carries identical genetic information
  47. Metaphase
    a stage in mitosis during which the chromosomes become arrange near the middle of the cell
  48. anaphase
    a stage in mitosis during which the centromeres split and the daughter chromosomes begin to seperate
  49. Telophase
    The last stage of mitosis, during which the chromosomes of the daughter cells decondense and the nucleus re-forms, spindle disappears
  50. Meiosis
    The process of cell division during which one cycle of chromosomal replication is followed by two successive cell divisions to produce four haploid cells
  51. diploid (2n)
    The condition in which each chromosome is represented twice as a member of a homologous pair
  52. Haploid (n)
    The condition in which each chromosome is represented once in an unpaired condition
  53. Homologous Chromosomes
    Chromosomes that physically associate (pair) during meiosis. Homologous chromosomes have identical gene loci
  54. Assortment
    the result of meiosis I that puts random combinations of maternal and paternal chromosomes into gametes
  55. Crossing over
    A process in which chromosomes physically exchange parts
  56. allele
    One of the possible alternative forms of a gene, usually distinguished from other alleles by its phenotypic effects-different alleles result from mutations
  57. spermatogonia
    mitotically active cells in the gonads of males that give rise to primary spermatocytes
  58. spermatids
    the four haploid cells produced by meiotic division of a primary spermatocyte
  59. oogonia
    mitotically active cells that produce primary oocytes
  60. secondary oocyte
    the large cell produced by the first meiotic division
  61. oocyte
    a cell from which and ovum develops by meiosis
  62. ovum
    haploid cell produced by meiosis that becomes the functional gamete
  63. polar bodies
    Cells produced in the first and second meiotic division in female meiosis that contain little cytoplasm and will not function as gametes
  64. dominant trait
    the trait expressed in the F1 (or heterozygous) condition
  65. recessive trait
    the trait unexpressed in the F1 but re-expressed in some members of the F2 generation.
  66. Phenotype
    the observable properties of an organism
  67. genotype
    the specific genetic constitution of an organism
  68. segregation
    the separation of members of a gene pair from each other during gamete formation
  69. homozygous
    having identical alleles for one or more genes
  70. heterozygous
    carrying two different alleles for one or more genes
  71. independent assortment
    the random distribution of alleles into gametes during meiosis
  72. locus
    the position occupied by a gene on a chromosome
  73. pedigree construction
    use of family history to determine how a trait is inherited and to estimate risk factors for family members
  74. pedigree
    a diagram listing the members and ancestral relationships in a family; used in the study of human heredity
  75. proband
    first affected family member who seeks medical attention for a genetic disorder
  76. incomplete dominance
    expression of a phenotype that is intermediate to those of the parents
  77. codominance
    full phenotypic expression of both members of a gene pair in the heterozygous condition
  78. multiple alleles
    genes that have more than two alleles
  79. Epistasis
    the interaction of two or more non-allelic genes to control a single phenotype
  80. population
    a group of interbreeding individuals who possess a particular collection of alleles or gene pool
  81. human genome
    3 billion base pairs of DNA28,000 to 34,000 genesorganized as 23 pairs of chromosomes (22+ X&Y)
  82. mutations
    changes on the DNA
  83. somatic cells
    majority of an individual's body, make proteins using different subsets of genes
  84. Germline cells
    within the testis or ovary produce gametes (sperm or ovum)
  85. prokaryotic cells
    lack a nucleus
  86. eukaryotic cells
    contain a nucleus and complex organelles
  87. Human cells
    >260 cellsFour catergories:Epithelial, muscle, nerve, conncetive
  88. peroxisomes
    contain several types of enzymes; break down lipids and rare biochemicals; synthesize bile acids; detoxify compounds from free radicals; abundunt in liver and kidney cells; Adrenoleukodystrophy (ALD)= inherited trait of a peroxisome enzyme transport protein
  89. plasma membrane
    double layered, dynamic and active, selectively permeable, regulates exchange of materials, contains molecules important in identity
  90. S phase
    DNA synthesis
  91. G phase
    gap for growth
  92. G naught/ G0
    cell stops dividing
  93. apoptosis
    cell death that is part of normal development
  94. necrosis
    cell death in response to injury
  95. telomeres
    located at the end of chromosomes, contain 100s to 1000s of six nucleotide repeats, lose 50-200 repeats after each division, signal cell to stop dividing after about 50 divisions
  96. telomerase
    produced by sperm, eggs, bone marrow, and cancer cells; prevents shortening of telomeres
  97. Autosomal dominant inheritance
    -heterozygotes exhibit the affected phenotype; males and females are equally affected and may transmit the trait; affected phenotype does not skip generations
  98. autosomal recessive inheritance
    heterozygotes carry the recessive allele but exhibit the wildtype phenotype; males and females are equally affected and may transmit the trait; may skip generations
  99. X- linked traits
    males are hemizygous, have trait or do not because they only have one X chromosomeFemales can be heterozygotes and inherit x chromosomes from both parents
  100. X-linked recessive traits
    always expressed in males, female homozygotes show the trait but heterozygotes do not
  101. cystic fibrosis
    an often fatal recessive genetic disorder associated with abnormal secretions of the exocrine glands
  102. x-linked
    the pattern of inheritance that results from genes located on the X-chromosome
  103. Y-linked
    the pattern of inheritance that results from genes located on the Y-chromosomes
  104. Hemizygous
    a gene present on the x chromosome that is expressed in males in both the recessive and the dominant conditions
  105. Color blindness
    Defective color vision caused by reduction or absence of visual pigments. There are three forms: red, green, and blue blindness
  106. Muscular dystrophy
    A group of genetic diseases associated with progressive degeneration of muscles. Two of these, Duchenne and Becker muscular dystrophy, are inherited as X-linked allelic recessive traits
  107. Huntington Disease
    An autosomal dominant disorder associated with progressive neural degeneration and dementia. Adult onset is followed by death 10-15 years after symptoms appear
  108. Penetrance
    The probability that a disease phenotype will appear when a disease-related genotype is present.
  109. Expressivity
    the range of phenotypes resulting from a given genotype
  110. Campotdactyly
    a dominant human genetic trait that is expressed as immobile, bent, little fingers
  111. Discontinuous variation
    phenotypes that fall into two or more distinct nonoverlapping classes
  112. continuous variation
    a distribution of phenotypic characters that is distributed from one extreme to another in an overlapping, or continuous, fashion
  113. Complex traits
    traits controlled by multiple genes, the interaction of genes with each other, and with environmental factors where the contributions of genes and environment are undefined
  114. polygenic traits
    traits controlled by two or more genes
  115. multifactorial traits
    traits controlled by two or more genes
  116. genetic variance
    the phenotypic variance of a trait in a population that is attributed to genotypic differences
  117. Heritability
    An expression of how much the observed variation in a phenotype is due to differences in genotype
  118. correlation coefficients
    An expression of how much the observed variation in a phenotype is due to differences in genotype
  119. correlation coefficients
    Measures the degree of interdependene of two or more variables
  120. monozygotic
    twins derived from a single fertilization involving one egg and one sperm, such twins are genetically identical
  121. Dizygotic
    twins derived from two separate and nearly simultaneous fertilizations, each involving one egg and one sperm. Such twins share, on average, 50% of their genes
  122. concordance
    agreement between traits exhibited by both twins
  123. leptin
    a hormone produced by fat cells that signals the brain and ovary. As fat levels become depleted, secretion of leptin slows and eventually stops
  124. Intelligence quotient (IQ)
    A score derived from standardized test that is calculated by dividing the individual's mental age (determined by the test) by his or her chronological age and multiplying the quotient by 100
  125. General cognitive ability
    Characteristics that include verbal and spatial abilities, memory, speed of perception, and reasoning
  126. metacentric
    describes a chromosome that has a centrally placed centromere
  127. submetacentric
    describes a chromosome whose centromere is placed closer to one end than the other
  128. acrocentric
    describes a chromosome whose centromere is placed very close to, but not at, one end
  129. amniocentesis
    a method of sampling the fluid surrounding the developing fetus by inserting a hollow needle and withdrawing suspended fetal cells and fluid; used in diagnosing fetal genetic and developmental disorders; usually performed in the sixteenth week of pregnancy
  130. chronic villus sampling (CVS)
    A method of sampling fetal chorionic cells by inserting a catheter through the vagina or abdominal wall into the uterus. Used in diagnosing biochemical and cytogenetic defects in the embryo. Usually performed in the eighth or ninth week of pregnancy
  131. polyploidy
    a chromosomal number that is a multiple of the normal haploid chromosomal set
  132. Aneuploidy
    a chromosomal number that is not an exact multiple of the haploid set
  133. monsomy
    a condition in which one member of a chromosomal pair is missing; having one less than the diploid number
  134. trisomy
    a condition in which one chromosome is present in three copies, whiereas all others are diploid; having one more than the diploid number
  135. triploidy
    a chromosomal number that is three times the haploid number, having three copies of all autosomes and three sex chromosomes
  136. Tetraploidy
    a chromosomal number that is four times the haploid number, having four copies of all autosomes and four sex chromosomes
  137. nondisjunction
    The failure of homologous chromosomes to separate properly during meiosis or mitosis
  138. Trisomy 21
    Aneuploidy involving the presence of an extra copy of chromosome 21, resulting in down syndrome
  139. Turner Syndrome
    A Monosomy of the x chromosome (45,x) that results in female sterility
  140. Klinefelter syndrome
    aneuploidy of the sex chromosomes involving an xxy chromosomal consitution
  141. XXY karyotype
    Aneuploidy of the sex chromosomes involving an xxy chromosomal condition
  142. cri du chat syndrome
    a deletion of the short arm of chromosome 5 associated with an array of congenital malformations, the most characteristic of which is an infant cry that resembles a meowing cat
  143. Uniparental disomy (UPD)
    a condition in which both copies of a chromosome are inherited from one parent
  144. copy number variation
    A dna segment at least 1000 base pairs long with a variable copy number in the genome
  145. Fragile X syndrome
    An X chromosome that carries a gap, or break, at band q27; associated with mental retardation in males
  146. Zygote
    the fertilized egg that develops into a new individual
  147. gametes
    unfertilized germ cells
  148. gonads
    organs where gametes are produced
  149. testes
    male gonads that produce spermatozoa and sex hormones
  150. ovaries
    female gonads that produce oocytes and female sex hormones
  151. scrotum
    a pouch of skin outside the male body that contains the testes
  152. seminiferous tubules
    small, tightly coiled tubes inside the testes where sperm are produced
  153. spermatogenesis
    the process of sperm production
  154. epididymis
    a part of the male reproductive system where sperm are stored
  155. vas deferens
    a duct connected to the epididymis which sperm travels through
  156. ejaculatory duct
    in males, a short connector from the vas deferens to the urethra
  157. urethra
    a tube that passes from the bladder and opens to the outside. It functions in urine transport and, in males, also carries sperm
  158. seminal vesicles
    Glands in males that secrete fructose and prostaglandins into the semen
  159. Prostaglandins
    locally acting chemical messengers that stimulate contraction of the female reproductive system to assist in sperm movement
  160. prostate gland
    a gland that secretes a milky, alkaline fluid that neutralizes acidic vaginal secretions and enhances sperm viability
  161. bulbourethral glands
    glands in the male that secret a mucus-like substance that provides lubrication for intercourse
  162. semen
    a mixture of sperm and various glandular secretions containing 5% spermatozoa
  163. Follicle
    developing egg surrounded by an outer layer of follicle cells, contained in the ovary
  164. oviduct
    a duct with fingerlike projections partially surrounding the ovary and connecting to the uterus. Also called the fallopian, or uterine, tube
  165. uterus
    a hollow pear-shaped muscular organ where an early embryo will implant and develop throughout pregnancy
  166. endometrium
    the inner lining of the uterus that is shed at menstruation if fertiliztion has not occured
  167. cervix
    the lower neck of the uterus, opening into the vagina
  168. vagina
    that opening that receives the penis during intercourse and also serves as the birth canal
  169. Oogenesis
    the process of oocyte production
  170. oogonia
    cells that produce primary oocytes by mitotic division
  171. chorion
    a two layered structure formed during embryonic development from the trophoblast
  172. Teratogen
    any physical or chemical agent that brigns about an increase in congenital malformations
  173. fetal alcohol syndrome
    constellation of birth defects caused by maternal alcohol consumption during pregnancy
  174. sex ratio
    the proportion of male to females, which changes throughout the life cycle. The ratio is close to 1:1 at fertilization, but the ratio of females to males increases as population ages
  175. SRY
    A gene, called the sex-determining region of the Y, located near the short arm or the y chromosome that plays a major role in causing the undifferentiated gonad to develop into a testis
  176. testosterone
    A steroid hormone produced by the testis; the male sex hormone
  177. Anti-mullerian hormone (AMH)
    A hormone produced by the devloping testis that causes the breakdown of the mullerian ducts in the embryo
  178. complete androgen insensitivity
    an x linked genetic trait that causes XY individuals to develop into phenotypic females
  179. pseudohermaphroditism
    an autosomal genetic condition that causes xy individuals to develop the phenotypic sex of females
  180. Dosage compensation
    a mechanism that regulates the expression of sex linked genes
  181. barr body
    a densely staining mass in teh somatic nuclei of mammalian females; an inactivated x chromosome
  182. lyon hypothesis
    the proposal that dosage compensation in mammalian females is accomplished by partially and randomly inactivating one of the two x chromosomes
  183. X inactivation center
    a region on the x chromosome where inactivation begins
  184. sex-influenced traits
    traits controlled by autosomal genes that are usually dominant in one sex but recessive in the other sex
  185. pattern baldness
    a sex influenced trait that acts like an autosomal dominant trait in males and an autosomal recessive trait in females
  186. sex-limited genes
    loci that produce a phenotype in only one sex
  187. imprinting
    a phenomenon in which expression of a gene depends on whether it is inherited from the mother of the father