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2011-09-30 21:17:40
vet tech theriogenology chapter Genetic Material definitions set

vet tech theriogenology chapter 1 Genetic Material and definitions set
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  1. Theriogenology
    • branch of veterinary science which comprises the study of the normal physiology and anatomy, and the
    • pathology and diseases of the male and female reproductive tracts of animals
  2. Cell
    the basic unit of structure and function of all living things
  3. Somatic cells
    cells of the body other than germ cells
  4. Germ cells (gonocytes)
    sex cells
  5. Deoxyribonucleic acid (DNA)
    • the genetic material in the nucleus of a cell.
    • The DNA is looped and curled to form the chromosome.
  6. Cell cycle
    the cell must synthesize new DNA before it divides causing a cycle of events in the life of a cell
  7. Meiosis
    • 1. cell division that takes place in the gonads (sex glands - ovaries and testes) to produce ova ond spermatozoa (gametes)
    • 2. process of cell division by which reproductive cells (gametes) are formed
  8. Chromosome
    • carry the genes
    • present in a fixed number for each species
    • in all the cell nuclei of plants, animals, and humans
  9. Gene
    the unit or element of a chromosome that carries and transfers an inherited characteristic from parent to offspring and determines the development of some particular character or trait in the offspring
  10. Diploid
    normal amount of DNA
  11. Haploid
    half the normal amount of DNA
  12. Congenital
    present at birth
  13. Phenotype
    outward appearance of an animal
  14. Genotype
    genetic makeup of an individual (inherited factors)
  15. Mitosis
    ordinary process of cell division, body replaces dead cells
  16. Centromere
    constriction or narrow point on the chromosome where it attaches to the cell spindle during cell division
  17. Cell spindle
    formed during metaphase (mitosis), microtubules radiating from the centrioles and connecting to the chromosomes of their centromeres
  18. Centriole
    • located in the centrosome
    • migrate to opposite poles of the cell during cell division and serve to organize the spindles
  19. Centrosome
    a specialized area of cytoplasm containing the centrioles
  20. Synaptonemal complex
    • protein structure that binds the two homologous chromosomes together along their long axis during meiosis
    • helps in pairing or "synapsis"
  21. Crossing over
    • homologous chromosomes line up next to each other and fuse at the chiasmata
    • genetic material is exchanged
    • importance of crossing over is that it produces new combinations of genes on the chromosomes
  22. Chiasmata
    point at which homologous chromosomes fuse for crossing over
  23. Inherited characteristics
    • come from ancestors (related animals), eg eye color, coat color
    • not always present at birth, may develop as animal matures eg spots on a dalmatian, color points, some diseases
  24. Acquired characteristics
    • caused by environment
    • appear in unrelated animals kept in the same manner of subjected to the same circumstances
    • eg unsocial feral cats
  25. Genetics
    • science that differentiates between inherited and acquired characteristics
    • provides an understanding of how characteristics are inherited
  26. Congenital
    • characteristic present at birth
    • not all congenital charateristics are inherited, eg injury in vivo
  27. Greg Mendel
    • science of genetics, mid-19th century, principls of heredity
    • 1900 biologists test and confirm Mendel's theory
    • 1944 discovery that genetic information stored in DNA
    • 1953 Watson and Crick (actually Rosalind Franklin) describe the double-helix structure of DNA
  28. Study of genetics divided into
    • Mendelian genetics
    • population genetics
    • Molecular genetics
    • cytogenetics
  29. Mendelian genetics
    • genetics of individuals and their families
    • characteristics governed by a single gene or just a few genes
    • describes how genes are passed from one generation to another
  30. Population genetics
    • studies genetic makeup of a larger group
    • characteristics governed by many genes
  31. Molecular genetics
    study of DNA and gene activity at the molecular level
  32. Cytogenetics
    study of chromosomes
  33. DNA molecule
    • consists of two parallel chains of atoms joined by cross links
    • chains are the same on both sides
    • - consist of a sugar molecule (deoxyribose) and a phosphate molecule
    • cross links are formed by pairs of the four bases
    • - adenine (A) with thymine (T) or
    • - guanine (G) with cytosine (C)
    • replicates and produces new molecules exactly the same as the first by breaking the link between the bases, then adding new units
    • can "store" genetic material because of its structure
    • not all DNA codes for something - most is "rubbish"
  34. Complimentary
    sequence of bases on one side determines the sequence of bases on the other
  35. Genetic code
    lies in the sequence of bases that form the DNA molecule
  36. Exons
    part of the DNA molecule that codes
  37. Introns
    non-coding bits of DNA
  38. Basic cell biology
    • two kinds of organisms - prokaryotes and eukaryotes
    • two basic varieties of cells - Somatic cells and germ cells
  39. Prokaryotes
    • no cell nucleus
    • DNA floats loosely in center of cell
    • eg bacteria
  40. Eukaryotes
    • have a well-defined nucleus to house and protect DNA
    • eg simple one-celled animals and plants, complex multicellular organisms (people and animals)
  41. Somatic cells
    • body cells
    • produced by mitosis
  42. Germ cells
    • sex cells
    • produced by meiosis
  43. Chromatin
    • formed in the nucleus from molecules of DNA coiled around protein, coiled again to form loops, loops coiled again
    • two types - euchromatin, heterochromatin
  44. Euchromatin
    chromatin that contains most of the functional genes
  45. Heterochromatin
    contains few functional genes ("rubbish")
  46. Chromosomes
    • separate units of chromatin
    • each species has a specific number of chromosomes
    • - cat 38 (19 pairs)
    • - dog 78 (39 pairs)
    • - horses 64 (32 pairs)
    • - humans 46 (23 pairs)
    • half of the chromosomes (one of each pair) comes from mother, other half from father
  47. Homologous chromosomes
    paired chromosomes are identcal to one another (according to which genes they carry)
  48. Sex chromosomes
    one pair of chromosomes that do not match each other morphologically and do not carry the same genes (X & Y)
  49. Autosomes
    • non-sex chromosomes
    • any chromosome other than the X & Y
  50. Normal cell life
    chromosomes elongated and distributed throughout the nucleus
  51. Replication of cell
    chromosomes condense and disentangle into separate entities
  52. Centromere
    constriction on the chromosome where it attached to the cell spindle during cell division
  53. Telomere
    • end of a chromosome
    • made of densely packed DNA
    • serves to protect the DNA message that chromosomes carry
  54. Centromere position and arm length
    • metacentric - centromere is in the middle
    • submetacentric - centromere is near the center on one side
    • acrocentric - centromere is on one side, closer to the end than the middle
    • telocentric - centromere is at the end
  55. Cell cycle and division
    • cell must synthesize new DNA before it can divide
    • four phases in division - S phase, Lag or G2 phase, M phase, G1 phase
  56. S phase
    DNA synthesis stage
  57. Lag or G2 phase
    • rest phase; second growth phase
    • growth and preparation for division
  58. M phase
    • division of the nucleus and cytoplasm
    • divided into subphases - PMAT - prophase, metaphase, anaphase, telophase
  59. G1 phase
    • daily work
    • growth and normal metabolic roles
  60. Interphase
    • G1, S, and Lag or G2 phases
    • everything but M phase
  61. Mitosis
    • replication or multiplication division
    • when cell divides, it produces two new cells which are exact copies of the original
    • has diploid amount of DNA
    • process of dividing up the newly copied chroosomes to make certain that the new cells each get a full set
  62. Meiosis
    • reduction division
    • gametes (sperm and ova) each have only half the amount of DNA
    • has haploid amount of DNA