1. autosomes and sex chromosomes
2. X and Y: An XX combination will create a female, an XY combination will create a male.
3.Autosomes are chromosomes that do not determine gender. There are 22 pairs (44) autosomes.
4.Homologous chromosomes are similar chromosomes. One has been donated from the mother and one from the father. Homologues contain the same genes but they may have different variations. For example: each chromosome may code for hair color, but one codes for black hair and one codes for red hair.
5. Diploid cells contain 2 copies of every gene whereas haploid cells only contain 1.
6. All somatic (body) cells in humans are diploid. The only two cells in humans that are haploid are gametes (sperm and ova [eggs]).
7. Diploid: 2n Haploid: n
8. meiosis and mitosis
9. somatic (body) cells
10. Meiosis reduces the amount of chromosomes in a cell by half.
11. Cells produced by meiosis are gametes. When two gametes fuse during fertilization they create a zygote (a fertilized egg) with two copies of every gene.
12. prophase, metaphase, anaphase, and telophase
13. Mitosis is division of the nucleus while cytokinesis is the division of the cytoplasm.
14. The 2 daughter cells created in mitosis will be identical in size with the identical number of chromosomes as was in the parent cell.
15. Meiosis is a form of nuclear division that divides a diploid cell into a haploid cell.
16. Germ cells that are made into gametes.
17. Meiosis produces sex cells called gametes (sperm and ova [eggs])
18. sperm and ova (eggs) / each have 23 chromosomes
19. 23 pairs (46)
20. The fertilization of a sperm and an ovum (egg) produces a zygote with 46 (2n) chromosome number.
21. twice
22. prophase I, metaphase I, Anaphase I, Telophase I, Prophase II, Metaphase II, Anaphase II, Telophase II
23. a. sister chromatids do not appear until meiosis II and they are separated during anaphase II
b. spindle forms during prophase I and breaks down during telophase I
c. nucleus divides
d. pair up in prophase I, separate during anaphase I
24. homologous chromosomes pair up (2 chromosomes, 4 chromatids)
25. segments of DNA exchange between the two homologous chromosomes
26.
27. DNA
28. variation
29. nuclear envelope reforms, spindle breaks down and cytoplasm divides to form 2 daughter cells
30. 2 (4 chromatids)
31. no
32. 4, 2 chromatids
33. production of mobile sperm, testes
34. male sex cells, 4 are produced
35. production of eggs, ovaries
36. the cytoplasm, organelles and dna are given by the egg cell, so the remainder stuff is left as polar bodies which are waste
37. polar bodies
38. genetically identical
39. genetically different
40. genetic variation allows for the possible adaptation of some organisms in a population in a changing environment
41. Deoxyribonucleic acid
42. store and carry genetic information
43. phosphate, deoxyribose sugar, nitrogen containing base
44. adenine, guanine, thymine, cytosine
45. purine-double ring, pyrimidine-single ring
46. adenine and guanine
47. cytosine and thymine
48. Watson and Crick- 1953
49. alternating sugars and phosphates held together by covalent bonds
50. nitrogen bases held together by hydrogen bonds
51. x ray crystallography to see the helix structure of DNA and that the steps were of approximately the same width.
52. hydrogen-weak
53. alternating phosphates and deoxyribose sugar held together by covalent bonds
54. adenine/thymine and guanine/cytosine
55. A always bond with T, C always bonds with G always have equal amounts of pyrimidines with purines.