Across
- 1. a cross between the F1 hybrids (Bb x Bb); produces a 3:1 ratio
- 6. DNA found in the mitochondria or chloroplasts (in animals all mitochondrial DNA is maternally inherited in the egg; in plants mitochondrial and chloroplast traits inherited maternally in the ovule)
- 7. a gene located on either the X or Y chromosome
- 9. the probability that 2 or more independent events will occur together in some specific combination
- 12. homozygous dominant and heterozygous individuals ate phenotypically the same
- 13. the transmission of traits from one generation to the next
- 14. the effect of two or more genes acting on a single phenotype (height, human skin color)
- 16. the probability that two or more mutually exclusive events will occur
- 17. individuals with the same genotype exhibit different phenotypes in different environments
- 20. genes for one trait are not inherited with genes of another trait (only applies to genes on different chromosomes or genes located far apart on the same chromosome)
- 21. sex cells; haploid or n: one set of each chromosome (humans-sperm and egg: n=23)
- 23. pairs of homologs line up at the metaphase plate, with one chromosome facing each pole; independent orientation occurs
- 24. a pair of chromosomes (same size, length, centromere position) that carry the same genetic information; one from mom one from dad
- 27. alternate versions of a gene
- 31. family trees that give a visual of inheritance patterns of particular traits
- 32. the genetic makeup (alleles) of an organism
- 34. the study of heredity and hereditary variation
- 35. during fertilization when sperm fuse with an egg (both haploid) to create the ________ (diploid)
- 38. overpowers the recessive trait, therefore only needs one allele to be expressed
- 40. genes found specifically on the Y chromosome (very few _____ genes, so very few disorders)
- 44. genes located near each other on the same chromosome that tend to be inherited together; show parental phenotypes in offspring at higher than 50%
- 45. body cells; diploid, or 2n: two complete sets of each chromosome (humans: 2n=46)
- 47. formed when one of the 2 X chromosomes in each cell in a female is randomly inactivated during development
- 48. only source of variation in organisms with asexual reproduction
- 49. the phenotypic expression of a gene at one locus affects a gene at another locus (coat color in labs and some mice – one gene for pigment and second gene determines in the pigment is shown)
- 51. single individual, no fusions of gametes, offspring are clones (other than mutations), can produce asexually through mitosis
- 56. a process that creates haploid gamete cells in sexually reproducing diploid organisms; results in daughter cells with half the number of chromosomes as the parent cell; involves 2 rounds of division (Meiosis 1 and Meiosis 2)
- 59. true-breeding parental generation
- 60. X and Y (eggs: X, sperm X or Y)
- 62. offspring with phenotypes that are different from the parents
- 64. offspring with the parental phenotype (look like the parent)
- 65. genes found on the X chromosome (mothers can pass down to all children, fathers only pass onto their daughters)
- 66. two complete sets of each chromosome, 2n
- 67. (second filial) offspring of the F1 generation)
- 68. 2 parents, offspring are unique combinations of genes from parents, genetically varied from parents and siblings
- 69. made by two homologous chromosomes; a set of 4
- 70. nuclei and cytoplasm divide; there is now a haploid set of chromosomes in each daughter cell
Down
- 2. trait that is only shown when there are two alleles not being masked by the dominant trait
- 3. end product of 4 haploid cells; nuclei reappear; each daughter cell is genetically unique
- 4. neither allele is fully dominant (white x red = pink)
- 5. pairs of homologous chromosomes separate; sister chromatids are still attached
- 8. sequence of stages in the reproductive history of an organism from conception to its own reproduction; fertilization and meiosis alternate in sexual life cycles
- 10. organisms that produce offspring of the same variety over many generations of self-pollination
- 11. homologous chromosomes pair up and physically connect to each other forming a tetrad
- 15. cell goes through G1, S (DNA is copied) and G2
- 17. diagrams used to predict the allele combinations of offspring from a cross with known genetic compositions
- 18. an organism that has a pair of identical alleles for a character
- 19. (first filial) hybrid offspring of P generation)
- 20. 2 alleles for the same trait separate during gamete formation and end up in different gamete cells
- 22. offspring are exact copies of each other
- 25. any sperm can fertilize any egg
- 26. chromosomes line up at the metaphase plate; because of crossing over in Meiosis I, the chromatids are unique
- 28. produces recombinant chromosomes; they exchange genetic material
- 29. genetic map that is based on recombination frequencies; distance between genes are map units
- 30. a display of chromosome pairs ordered by size and length
- 33. chromosomes fail to separate properly in meiosis I or meiosis II; karyotyping can detect nondisjunction (ex. Down syndrome w/ 3 copies of chromosome 21)
- 36. refers to genes on the X chromosome of males, which is expressed whether dominant or recessive (the term homozygous does not apply)
- 37. results from the fertilization of gametes in which nondisjunction occurred; number of chromosomes a cell has doesn’t equal 46
- 39. genes that exist in forms with more than two alleles (human blood group: I^A, I^B, i)
- 41. chromosomes are randomly oriented along the metaphase plate during Metaphase I; each can orient with either the maternal or paternal chromosomes closer to a given pole
- 42. a cross between F1 dihybrids (YyRr x YyRr); produces a 9:3:3:1
- 43. (X^2) a form of statistical analysis used to compare the actual results (observed with the expected results); used to test the null hypothesis (X^2 = sum of (O-E)^2/E
- 46. a point of contact between chromosomes during meiosis where two chromatids interchange corresponding segments
- 50. synapsis (form a tetrad), crossing over (recombination)
- 52. sister chromatids separate and move towards opposite poles
- 53. no crossing over; spindle fibers form
- 54. an organism that has two different alleles for a gene
- 55. two alleles that affect phenotype are both expressed (type AB blood = A + B both expressed)
- 57. an organism’s appearance, which is determined by the genotype
- 58. segments of DNA that code for basic units of heredity
- 61. one set of each chromosome, n
- 63. chromosomes that do not determine sex (humans have 22 pair)