1. Genetics

2. The two major groups of specialized cells in your body are _______ and ________.
Somatic cells and germ cells

3. ______ cells, also called body cells, make up most of your body tissues and organs.
Somatic cells

4. DNA is passed on to offspring by ____ ___.
Germ cells

5. Gametes are ____ cells.
sex

6. Each species has a characteristic number of ______ per cell.
chromosomes

7. Chromosome number does not seem to be related to the _______ of an organism.
complexity

8. Humans have ___ chromosomes in ___ pairs.
46, 23

9. Humans receive 23 chromosomes from the _____ and 23 from the _____.
Mother, father

10. In humans, each pair of chromosomes is referred to as a ________ ____.
Homologous pair

11. Homologous means…….
Having the same structure

12. A number has been assigned to each homologous pair, ordered from _____ to _____.
Largest to smallest

13. Chromosome pairs 1-22 make up your ______.
autosomes

14. These chromosomes are not directly related to the sex of an organism.
autosomes (1-22)

15. The two human sex chromosomes are __ and __.
x and y

16. An organism with two X chromosomes is _____.
female

17. An organism with one X chromosome and one Y chromosome is ____.
male

18. X and Y chromosomes are not _______.
homologous

19. The ____ chromosome is larger and contains numerous genes.X

20. ______ _______ involves the fusion of two gametes that results in offspring that are a genetic mixture of both parents.
Sexual reproduction

21. The actual fusion of an egg and sperm cell is called _______.
fertilization

22. When fertilization occurs, the nuclei of the egg and sperm cell fuse to form one _____.
nucleus

23. Egg and sperm cells only have half the usual number of ______.
chromosomes

24. Body cells are ____, meaning that a cell has two copies of each chromosome.
diploid

25. Gamete cells are _____, meaning that one cell has one copy of each chromosome.
haploid

26. The sex of an individual is determined by the _____.
Male (for humans)

27. Increasing the number of sets of chromosomes can give rise to a new _____.
species

28. 4 copies of each chromosome.
A condition called tetraploidy

29. Germ cells in human reproductive organs undergo _____ to form gametes.
meiosis

30. ______ is a form of nuclear division that divides a diploid cell into haploid cells.
meiosis

31. ______ is a type of cell division that occurs in body cells.
Mitosis

32. What are some of the differences between mitosis an meiosis?
In mitosis, DNA is copied once and divided once. In meiosis, DNA is copied once but divided twice.
In mitosis, daughter cells are genetically identical to the parent cell. Meiosis makes genetically unique haploid cells from a diploid cell.
Mitosis is used for growth, development, and repair. Takes place throughout life. Meiosis, however, takes place only at certain times.
Mitosis is involved in asexual reproduction, meiosis is involved in sexual reproduction.

33. Where are germ cells located in the human body?
Ovaries and testes
What is the difference between an autosome and a sex chromosome?
Autosomes, chromosomes 1-22, are not directly related to the sex of an organism.

34. Is the cell that results from fertilization a haploid or diploid cell
Is the cell that results from fertilization a haploid or diploid cell? Explain.
Each cell has only one copy of each chromosome. It takes the combination of an egg and sperm cell to make the 46 human chromosomes…..so haploid.

35. Does meiosis or mitosis occur more frequently in your body?
Mitosis, it is responsible for growth, development, and repair.
Meiosis is responsible for reproduction.

36. _______ is a form of nuclear division that creates four haploid cells from one diploid cell.
Meiosis
Meiosis _______ chromosome number and creates genetic _________.
reduces,diversity

37. Each half of a duplicated chromosome is called a ________.
Chromatid
______ ______ are the duplicated chromosomes that remain attached by the centromere.
Sister Chromatids

38. ______ ______ are divided during meiosis I.
____ ______ are not divided until meiosis II.
Homologous chromosomes
Sister chromatids

39. Before meiosis begins, _______ has already been copied.
DNA
What are the 4 stages of meiosis I?
Prophase I
Metaphase I
Anaphase I
Telophase I

40. Identify the phase in meiosis I.
The nuclear membrane breaks down centrosomes and centioles move to opposite sides of the cell. Spindle fibers assemble Homologous chromosomes pair up
Prophase I

41. Identify the phase in Meiosis I
Homologous chromosome pairs are randomly lined up along the middle of the cell by spindle fibers.
Metaphase I

42. Identify the phase in Meiosis I
Paired homologous chromosomes separate and move to opposite sides of the cell.
Anaphase I

43. Identify the phase in Meiosis I
The nuclear membrane forms, the spindle fibers disassemble, and the cell undergoes cytokinesis.
Telophase I

44. Identify the phase in Meiosis II
The nuclear membrane breaks down, centrosomes and centrioles move to opposite sides of the cell, spindle fibers assemble.
Prophase II

45. Identify the phase in Meiosis II
Spindle fibers align the 23 chromosomes at the cell equator
Metaphase II

46. Identify the phase in Meiosis II
The sister chromatids are pulled apart from each other and move to opposite sides of the cell.
Anaphase II

47. Identify the phase of Meiosis II
Nuclear membranes form around each set of chromosomes at opposite ends of the cell, spindle fibers break apart, the cell undergoes cytokinesis, and four haploid cells are produced.
Telophase II

48. What is the major difference between Metaphase I and Metaphase II?
In metaphase I, pairs of homologous chromosomes line up at the equator. In metaphase II, the chromosomes are not paired.

49. What is the major difference between Anaphase I and Anaphase II?
Sister chromatids remain together in Anaphase I but separate in Anaphase II.

50. ___________ is the production of gametes.
Gametogenesis

51. The sperm cell’s main contribution to an embryo is ____________.
DNA

52. Distinguishing characteristics that are inherited, such as eye color, leaf shape, and tail length.
Traits

53. The study of biological inheritance patterns and variation in organisms.
Genetics

54. The groundwork for genetics was laid in the middle 1800’s by an Austrian monk named ________ ________.
Gregor Mendel

55. What three key choices did Mendel make in his experiments that helped him develop his laws of inheritance?
Control over breeding
Use of purebred plants
Observation of “either-or” traits that appeared in only two alternate forms

56. Why did Mendel choose pea plants for his experiments?
They reproduce quickly and it is easy to control fertilization

57. Genetic Uniformity. The offspring inherit all of the parent organisms’ characteristics.
purebred

58. What seven traits for pea plants did Mendel observe?
Pea shape
Pea color
Pod shape
Pod color
Plant height
Flower color
Flower position

59. In genetics, the mating of two organisms is called a …
cross

60. Mendel called the very first purebred generation of pea plants the ________, or ________ generation.
Parental or P

61. Mendel called the offspring of the parental generation the ______ ______ generation.
First filial

62. Mendel called the generation after the first filial generation the ________ generation.

63. What happened with Mendel’s F₂ generation?
Plants were produced with both purple and white flowers, the entire F₁ generation produced purple flowers, the trait for white flowers had not disappeared; it had been masked.

64. What pattern did Mendel notice in the F2 generation?
Similar ratios were noticeable

65. What conclusions did Mendel draw from his observations?
Traits are inherited as discrete units.
Organisms inherit two copies of each gene, one from each parent.
Organisms donate only one copy of each gene in their gametes.

66. A piece of DNA that provides a set of instructions to a cell to make a certain protein.
Gene

67. Any of the alternative forms of a gene that may occur at a specific locus.
Allele

68. Your cells have ______ alleles for each gene.
Two

69. A term used to describe two of the same alleles at a specific locus.
Homozygous

70. A term used to describe two different alleles at a specific locus.
Heterozygous

71. All of an organism’s genetic material.
Genome

72. This term refers to the genetic makeup of a specific set of genes.
Genotype

73. The physical characteristics, or traits, of an individual make up its ________.
Phenotype

74. The allele that is expressed when two different alleles are present.
Dominant

75. The allele that is expressed when two copies are present.
Recessive

76. A grid system for predicting all possible genotypes resulting from a cross.
Punnett Square

77. What do the letters on the axes of the punnett square represent?
The condition of alleles from each parent.

78. A cross that examines the inheritance of only one specific trait.
Monohybrid crosses

79. FF
Homozygous Dominant

80. ff
Homozygous Recessive

81. Ff
Heterogygous Parent

82. A cross between an organism with an unknown genotype and an organism with the recessive phenotype.
Test-cross

83. From an FF x ff cross, what percent of offspring would have purple flowers? (Purple being dominant)
100% F f Ff

84. From an Ff x Ff cross, what percent of offspring would have purple flowers? (purple being dominant)
75% F f FF Ff

85. From an ff x Ff cross, what percent of offspring would have purple flowers? (purple being dominant)
50% f F Ff ff

86. Crosses that examine the inheritance of two different traits.
Dihybrid crosses

87. Allele pairs separate independently of each other during gamete formation, or meiosis. Different traits appear to be inherited separately.
The Law of Independent Assortment, The Second Law of Genetics

88. The likelihood that a particular event will happen
probability

89. Number of ways a specific even can occur Number of total possible outcomes
Probability

90. Why does the expected genotypic ratio often differ from the expected phenotypic ratio resulting from a monohybrid cross?
Multiple genotypes can cause the same phenotype. The homozygous dominant genotype and the heterozygous genotype yield the same phenotype in simple dominant-recessive cases

91. What is the major advantage of sexual reproduction?
It gives rise to a great deal of genetic variation

92. Genetic variation within species results largely from
The independent assortment of chromosomes during meiosis and the random fertilization of gametes

93. The exchange of chromosome segments between homologous chromosomes during prophase-I of meiosis-I
Crossing over

94. Any mixing of parental alleles
recombination

95. Genes located close together tend to be inherited together.
Genetic linkage

96. How does crossing over contribute to genetic diversity?
Crossing over makes new combinations of maternal and paternal genes

97. The word meiosis comes from a Greek word meaning “to diminish”, or make less. How does this word’s origin relate to its meaning?
Meiosis is a reductive process that diminishes, or reduces, the amount of DNA. It begins with a diploid cell and ends with haploid cells.

98. A fruit fly has diploid cells with 8 chromosomes
A fruit fly has diploid cells with 8 chromosomes. Explain how many chromosomes are in its haploid gametes
4 chromosomes, because meiosis results in haploid gamete cells, with only one set of chromosomes.

99. Many human genetic disorders are caused by _______ genes.
autosomal

100. For a genetic disorder to be caused by a recessive allele, ____ _______ must be present for a person to have the disorder.
Two copies

101. An individual who does not show disease symptoms but can pass on the disease causing allele to offspring.
Carrier

102. Genes located on the sex chromosome
Sex-linked genes

103. Males (XY) have only one copy of each type of sex chromosome
Males (XY) have only one copy of each type of sex chromosome. Because of this, males express ____ alleles on both chromosomes, even if all alleles are _______.
All, recessive

104. In female mammals, this is when one of the two X chromosomes is randomly turned off.
X-chromosome inactivation

105. Why are males more likely than females to have sex-linked genetic disorders?
All sex-linked genes, even recessive ones, are expressed in males.

106. How are autosomal traits, including recessive genetic disorders, related to Mendel’s observation of heredity?
Two copies of autosomal genes affect phenotype, as observed in all of Mendel’s crosses

107. How might a scientist determine whether a trait is sex-linked by observing the offspring of several genetic crosses?
If more males than females have a particular phenotype, the trait is probably sex-linked

108. Why are female calico cats white, black, and orange, while male calico cats are white and orange or white and black?
Males cats have only one X chromosome.

109. Does dominance mean that one allele defeats the other?
No. The dominant allele usually codes for a specific protein. The recessive allele codes for a variation of the protein that has little or no effect.

110. Neither allele is completely dominant or completely recessive.
Incomplete dominance

111. What are two examples of incomplete dominance?
The 4 o’clock plant. When plants that are homozygous for red flowers are crossed with plants that are homozygous for white flowers, the offspring have pink flowers.
The color of betta fish. When a green betta fish is crossed with a steel blue fish, the result is a royal blue betta fish.

112. The expression of both alleles of a gene
The expression of both alleles of a gene. Neither allele is dominant or recessive.
codominance

113. Provide an example of codominance.
A flower that has red and white splotches. The human ABO blood type.

114. Traits produced by two or more genes.
polygenic

115. A lack of pigment in skin
Albinism

116. In what ways may environment interact with genotype?
For sea turtles, eggs that mature in warmer temperature develop into females. Cooler temperatures result in males.
Amount of available nutrients during developmental stages of life may affect size

117. What two scientists first described gene linkage?
William Bateson and RC Punnett

118. Traits that are inherited together.
Linked traits or gene linkage