2. Chapter 10 Sexual Reproduction
and Genetics
Section 1: Meiosis
Section 2: Mendelian Genetics
Section 3: Gene Linkage and Polyploidy

3. Vocabulary
*Gene - segments of DNA located on chromosomes that control inherited traits; passed on from one generation to another generation
Gene

4. *Chromosome - DNA containing structure that carries genetic material from one generation to another

5. Homologous chromosomes - One of two paired chromosomes, one from each parent, that carries genes for a specific trait at the same location

6. *Synapsis - the pairing of homologous chromosomes during meiosis

7. *Crossing over - Exchange of chromosomal segments between a pair of homologous chromosomes during prophase 1 of meiosis

8. *Gamete - A haploid sex cell, formed during meiosis, that can combine with another haploid sex cell and produce a diploid fertilized egg; egg or sperm *Haploid - Cell with half the number of chromosomes (n) as a diploid (2n) cell Cell with half the number of chromosomes (n) as a diploid (2n) cell n - Used to represent the number of chromosomes in a gamete; haploid

9. *Meiosis - Reduction division process, occurring only in reproductive cells, in which one diploid (2n) cell produces four haploid (n) cells that are not genetically identical

10. *Fertilization - Process by which haploid gametes combine, forming a diploid cell with 2n chromosomes, with n chromosomes from the female parent and n chromosomes from the male parent

11. *diploid - A cell that contains both sets of homologous chromosomes; represented by 2n
2n - Results after fertilization; n chromosomes from female parent and n chromosomes from the male parent; diploid

12. Asexual reproduction - Organism inherits all of its genes from a single parent

13. Genetic variation - Different form of a gene results in different expression in the form of genetic makeup and outward appearance

14. Sexual Reproduction - Organism inherits all of its genes from two parents

15. Chapter 10 section 1 Meiosis
Main Idea:
Meiosis produces haploid gametes.

16. Human body cells have 46 chromosomes.
2. Each parent contributes 23 chromosomes,
resulting in 23 pairs of
chromosomes.

17. Chapter 10
Sexual Reproduction and Genetics
10.1 Meiosis
3. The chromosomes that make up a pair, one chromosome from each parent, are called homologous chromosomes.
4. Homologous chromosomes in body cells have the same length and the same centromere position and they carry genes that control the same inherited traits.

18. 5. In order to maintain the same chromosome number from generation to generation, an organism produces gametes, which are sex cells that have half the number of chromosomes.

19. Meiosis Reduces the genetic material by half Why is this necessary?
from mother
from father
child
too
much!
meiosis reduces genetic content

20. Haploid and Diploid Cells
Chapter 10
Sexual Reproduction and Genetics
10.1 Meiosis
Haploid and Diploid Cells
6. In humans, each gamete contain 23 chromosomes.

21. ploidy - how many times each chromosome is present in a cell.
Diploid – 2 copies of each chromosome
Triploid – 3 copies of each chromosome
Haploid – half the number of each chromosome

22. 7. A cell with n chromosomes is called a haploid cell.
8. A cell that contains 2n chromosomes is called a diploid cell.

23. Chapter 10
Sexual Reproduction and Genetics
10.1 Meiosis
9. Gametes are formed during a process called meiosis, which is a type of cell division that reduces the number of chromosomes; therefore, it is referred to as reduction division.

24. 10. Meiosis occurs in the reproductive structures of organisms that reproduce sexually.

25. 11. Meiosis reduces the chromosome number by half through the separation of homologous chromosomes.

26. 12. A cell with 2n number of chromosomes will have gametes with n number of chromosomes after meiosis.
Fertilization-
Process by which one
Haploid gamete combines
With another haploid
gamete

27. 13. Meiosis involves two consecutive cell divisions called meiosis I and meiosis II.

28. 14. Mitosis consists of only one set of division phases and produces two identical diploid daughter cells. Meiosis consists of two sets of divisions and produces four haploid daughter cells that are not identical.

29. Meiosis is important because it results in genetic variation.

30. 16.Pair of homologous chromosomes line up at the equator during metaphase I. How the chromosomes line up is a random process that results in gametes with different combinations of chromosomes.

31. 17. Depending on how the chromosomes line up at the equator, four gametes with four different combinations of chromosomes can result.

32. 18. Genetic variation also is produced during crossing over and fertilization, when gametes randomly combine.

33. 19. During asexual reproduction, the organism inherits all of its chromosomes from a single parent. The new individual is genetically identical to its parent.

34. 10.2 Vocabulary Mendelian Genetics
True breeding - plant consistently produces offspring with only one form of a trait
Self fertilization - when a male gamete within a flower combines with a female gamete in the same flower
Cross pollination - transferring a male gamete from the flower of one pea plant to the female reproductive organ in a flower of another pea plant

35. Genetics - Science of heredity P generation - Parent generation; true breeding; Cross between parents with different forms of a trait F1 generation - The offspring of the P cross are called the first filial (F1) generation; filius is Latin for son F2 generation - The offspring of the f1 generation

36. Allele - Alternative form that a single gene may have for a particular trait *Traits - Characteristics that are inherited Dominant - Mendel’s name for a specific trait that appeared in the F1 generation Recessive - Mendel’s name for a specific trait hidden or masked in the F1 generation

37. Homozygous - Organism with two of the same alleles for a specific trait; YY or yy Heterozygous - Organism with two different alleles for a specific trait; Yy Hybrid - Organism heterozygous for a specific trait; Yy

38. Genotype - An organism’s allele pairs; genetic makeup; the letters that represent the genes Phenotype - Observable characteristic that is expressed as a result of an allele pair; physical appearance Law of Segregation - Mendelian law stating that two alleles for each trait separate during meiosis

39. Monohybrid cross - A cross between hybrids for a single trait; Yy x Yy; Dihybrid cross - A cross between hybrids for 2 traits; YyRr Law of Independent Assortment - Mendelian law stating that a random distribution of alleles occurs during gamete formation; demonstrated in the dihybrid cross by the equal chance that each pair of alleles

40. *FOIL Method - used to determine gametes in a dihybrid; Punnett Squares - Used to predict the possible ratios of offspring of a cross between two known genotypes; keeps track of possible genotypes involved in a cross *Probability - likelihood that a particular event will occur; helps to predict the average outcome of a large number of events

41. 10.2 Mendelian Genetics
Main Idea - Mendel explained how a dominant allele can mask (hide) the presence of a recessive allele.

42. Gregor Mendel
1866
Austrian monk
Plant breeder
Mendel was the first person to succeed in predicting how traits are transferred from one generation to the next.

43. Chapter 10
Sexual Reproduction and Genetics
10.2 Mendelian Genetics
How Genetics Began
The passing of traits to the next generation is called inheritance, or heredity.

44. 2. Mendel chose to study pea plants.
Contrasting characters- green & yellow
wrinkled & round
Reproduce sexually
Crosses can be controlled
Short life cycles
Produce large number of offspring

45. In nature the pea plants are true (pure) breeding.
True (pure) breeding means that the pea plant consistently produces offspring with only one form of a trait.
Self-fertilization occurs when a male gamete within a flower combines with a female gamete in the same flower.
Result: the plant will have characteristics only from 1 parent
Short pea plant
Tall pea plant

46. 5. Mendel performed cross pollination by transferring a male gamete from the flower of one pea plant to the female reproductive organ in a flower of another pea plant.

47. Section 10.1 Summary – pages 253-262
Mendel was a careful researcher
He studied only one trait at a time to control variables, and he analyzed his data mathematically.
The tall pea plants he worked with were from populations of plants that had been tall for many generations and had always produced tall offspring.
Section 10.1 Summary – pages

48. 6. Genetics is the scientific study of heredity.

49. 7. The parent generation is also known as the P generation.
Chapter 10
Sexual Reproduction and Genetics
10.2 Mendelian Genetics
7. The parent generation is also known as the P generation.
Cross between parents with different forms of a trait

50. Chapter 10
Sexual Reproduction and Genetics
10.2 Mendelian Genetics
8. The offspring of this P cross are called the first filial (F1) generation.
Filius-latin for son

51. Chapter 10
Sexual Reproduction and Genetics
10.2 Mendelian Genetics
9. The second filial (F2) generation is the offspring from the F1 cross.

52. 10. F2 generation plants from these crosses showed a 3:1 ratio.
How did green reoccur?

53. Section 10.1 Summary – pages 253-262
11.Mendel studied 7 different traits in the pea plants he bred.
Seed
shape
Seed
color
Flower
color
Flower
position
Pod
color
Pod
shape
Plant
height
Dominant
trait
axial
(side)
round
yellow
purple
green
inflated
tall
Recessive
trait
terminal
(tips)
wrinkled
green
white
yellow
constricted
short
Section 10.1 Summary – pages

54. Section 10.1 Summary – pages 253-262
The rule of unit factors
Mendel concluded that each organism has two factors that control each of its traits.
We now know that these factors are genes and that they are located on chromosomes.
12. Allele – an alternative form of a single gene passed from generation to generation. Ex. Pod color in peas – yellow or green
Section 10.1 Summary – pages

55. Section 10.1 Summary – pages 253-262
The rule of dominance
13. Dominant – a form of trait that can mask or hide another form of a same trait. Ex. In peas the color yellow pod is dominant—represented by capital letter for allele.
Section 10.1 Summary – pages

56. Recessive – a form of trait that can be masked or hidden by the dominant form- ex. In peas the color green pod is recessive—represented by lower case letter
Mendel concluded that the allele for yellow peas is dominant to the allele for green peas.

57. Section 10.1 Summary – pages 253-262
The rule of dominance
When recording the results of crosses, it is customary to use the same letter for different alleles of the same gene.
Tall plant
Short plant T T t t T t F1
All tall plants T t
Section 10.1 Summary – pages

58. Section 10.1 Summary – pages 253-262
Phenotypes and Genotypes
15.An organism with two of the same alleles for a particular trait is homozygous. (Ex. YY, yy or RR, rr)
16. An organism with two different alleles for a particular trait is heterozygous (ex. Yy or Rr). When alleles are present in a heterozygous state, the dominant trait will be observed
Section 10.1 Summary – pages

59. Section 10.1 Summary – pages 253-262
Phenotypes and Genotypes
17. An organism’s allele pairs are called its genotype.
18. The observable characteristics or outward expression of an allele pair is called the phenotype.
An organism’s genotype can’t always be known by its phenotype.
Section 10.1 Summary – pages

60. Chapter 10
Sexual Reproduction and Genetics
10.2 Mendelian Genetics
19. Mendel’s Law of Segregation states that two alleles for each trait separate during meiosis.

61. 20. During fertilization, two alleles for that trait unite.
Chapter 10
Sexual Reproduction and Genetics
10.2 Mendelian Genetics
20. During fertilization, two alleles for that trait unite.

62. 21. Heterozygous organisms are called hybrids.

63. 22. Crosses that study a single trait. Genotypic ratio 1:2:1
Chapter 10
Sexual Reproduction and Genetics
10.2 Mendelian Genetics
Monohybrid Cross
22. Crosses that study a single trait.
Genotypic ratio 1:2:1
Phenotypic ratio 3:1

64. Chapter 10
Sexual Reproduction and Genetics
10.2 Mendelian Genetics
Dihybrid Cross
23. Crosses that study two or more traits. These F1 generation plants are called dihybrids because they are heterozygous for each trait .

65. 24. Law of Independent Assortment states that a
Chapter 10
Sexual Reproduction and Genetics
10.2 Mendelian Genetics
24. Law of Independent Assortment states that a
random distribution of alleles occurs during gamete formation. This result in the formation of 4 gametes.
25. Genes on separate chromosomes sort independently during meiosis.
26. Each allele combination is equally likely to occur.
27. These results represent a 9:3:3:1 phenotypic ratio.

66. Equal chance that each pair of alleles can randomly combine with each other
Possible allele
combinations in
gametes
Alleles in parental cell
Gamete formation YR Y y R r Yr yR yr

67. Section 10.1 Summary – pages 253-262
Punnett Squares
In 1905, Reginald Punnett, an English biologist, devised a shorthand way of finding the expected proportions of possible genotypes in the offspring of a cross.
This method is called a Punnett squares.
28. Punnett Squares predict the possible offspring or results of a cross between two known genotypes.
Section 10.1 Summary – pages

68. Predict the possible offspring of a cross between two known genotypes
Chapter 10
Sexual Reproduction and Genetics
10.2 Mendelian Genetics
Punnett Squares
Predict the possible offspring of a cross between two known genotypes
Punnett Squares

69. Section 10.1 Summary – pages 253-262
Probability
29. The principles of probability can be used to predict the outcomes of genetic crosses.
Section 10.1 Summary – pages

70. Section 10.1 Summary – pages 253-262
Probability R r
The Punnett square shows three plants with round seeds out of four total plants, so the probability is 3/4. RR Rr R Rr rr r
Section 10.1 Summary – pages

71. Punnett Square—Dihybrid Cross
Chapter 10
Sexual Reproduction and Genetics
10.2 Mendelian Genetics
Punnett Square—Dihybrid Cross
Four types of alleles from the male gametes and four types of alleles from the female gametes can be produced.
The resulting phenotypic ratio is 9:3:3:1.

72. “FOIL” Method used to determine gametes in a dihybrid
F = first of each pair
O = outer two
I = inner two
L = last of each pair
BbTt = gametes would be BT,Bt,bT,bt
Remember to keep homologous pairs of chromosomes together when combining gametes to form offspring.
BbTt NOT BTbt
Always place the dominant allele first in a homologous pair of chromosomes.
BbTt NOT bBtT

73. P =
Phenotype ratio __________________________

74. Dihybrid Cross

75. 10.3 Gene Linkage and Polyploidy
Objectives:
Summarize how the process of meiosis produces genetic variation.
Explain how gene linkage can be used to create chromosome maps.
Analyze why polyploidy is important to the field of agriculture.

76. Chapter 10
Sexual Reproduction and Genetics
10.3 Gene Linkage and Polyploidy
1. Genetic Recombination is the new combination of genes produced by crossing over and independent assortment
2. Combinations of genes due to independent assortment can be calculated using the formula 2n, where n is the number of chromosome pairs.

78. 3. Genes that are located close together on the same chromosome are said to be linked and usually travel together during gamete formation.

79. 10.3 Gene Linkage and Polyploidy
Chapter 10
Sexual Reproduction and Genetics
10.3 Gene Linkage and Polyploidy
Gene Linkage
4. The linkage of genes on a chromosome results in an exception to Mendel’s law of independent assortment because linked genes usually do not segregate independently.

80. Crossing over occurs more frequently between genes that are far apart than those that are close together.
1st chromosome maps were constructed on data from fruit fly crosses.

81. 7. Chromosome map percentages represent relative positions on the genes. 8. The higher the crossover frequency, the farther apart the two genes are.

83. 1. Polyploidy is the occurrence of one or more extra sets of all
Chapter 10
Sexual Reproduction and Genetics
10.3 Gene Linkage and Polyploidy
Polyploidy
1. Polyploidy is the occurrence of one or more extra
sets of all
chromosomes
in an organism.
2.A triploid organism, for instance, would be designated 3n,
which means that
it has 3 complete sets of chromosomes.

84. 3. Polyploidy rarely occurs in animals
3. Polyploidy rarely occurs in animals. In humans, polyploidy is always lethal. 4. Roughly one in three species of known flowering plants are polyploidy. Often they have increased vigor and size. Vigor -active healthy well-balanced growth especially of plants

85. Chapter Resource Menu Chapter Diagnostic Questions
Sexual Reproduction and Genetics
Chapter Resource Menu
Chapter Diagnostic Questions
Formative Test Questions
Chapter Assessment Questions
Standardized Test Practice
biologygmh.com
Glencoe Biology Transparencies
Image Bank
Vocabulary
Animation
Click on a hyperlink to view the corresponding lesson.

86. Chromosomes replicate.
Chapter 10
Sexual Reproduction and Genetics
10.1 Meiosis
Meiosis I
Interphase
Chromosomes replicate.
Chromatin condenses.
Interphase

87. Pairing of homologous chromosomes occurs.
Chapter 10
Sexual Reproduction and Genetics
10.1 Meiosis
Meiosis I
Prophase I
Pairing of homologous chromosomes occurs.
Each chromosome consists of two chromatids.
Prophase I
The nuclear envelope breaks down.
Spindles form.

88. Crossing over produces exchange of genetic information.
Chapter 10
Sexual Reproduction and Genetics
10.1 Meiosis
Meiosis I
Prophase I
Crossing over produces exchange of genetic information.
Crossing over—chromosomal segments are exchanged between a pair of homologous chromosomes.

89. Chromosome centromeres attach to spindle fibers.
Chapter 10
Sexual Reproduction and Genetics
10.1 Meiosis
Meiosis I
Metaphase I
Chromosome centromeres attach to spindle fibers.
Metaphase I
Homologous chromosomes line up at the equator.

90. Homologous chromosomes separate and move
Chapter 10
Sexual Reproduction and Genetics
10.1 Meiosis
Meiosis I
Anaphase I
Homologous chromosomes separate and move
to opposite poles of the cell.
Anaphase I

91. The spindles break down.
Chapter 10
Sexual Reproduction and Genetics
10.1 Meiosis
Meiosis I
Telophase I
The spindles break down.
Telophase I
Chromosomes uncoil and form two nuclei.
The cell divides.

92. A second set of phases begins
Chapter 10
Sexual Reproduction and Genetics
10.1 Meiosis
Meiosis II
Prophase II
A second set of phases begins
as the spindle apparatus forms and the
chromosomes condense.
Prophase II

93. A haploid number of chromosomes
Chapter 10
Sexual Reproduction and Genetics
10.1 Meiosis
Meiosis II
Metaphase II
A haploid number of chromosomes
line up at the equator.
Metaphase II

94. The sister chromatids are
Chapter 10
Sexual Reproduction and Genetics
10.1 Meiosis
Meiosis II
Anaphase II
The sister chromatids are
pulled apart at the centromere by spindle
fibers and move toward the opposite poles
of the cell.
Anaphase II

95. The chromosomes reach the poles, and
Chapter 10
Sexual Reproduction and Genetics
10.1 Meiosis
Meiosis II
Telophase II
The chromosomes reach the poles, and
the nuclear membrane and nuclei reform.
Telophase II

96. Chapter 10
Sexual Reproduction and Genetics
10.1 Meiosis
Meiosis II
Cytokinesis results in four haploid cells, each with n number of chromosomes.
Cytokinesis
Visualizing Meiosis I and Meiosis II

97. 1. Which symbol is used to represent the
Chapter 10
Sexual Reproduction and Genetics
Chapter Diagnostic Questions
1. Which symbol is used to represent the
number of chromosomes in a gamete? # x r n

98. 2. Segments of DNA that control the
Chapter 10
Sexual Reproduction and Genetics
10.1 Formative Questions
2. Segments of DNA that control the
production of proteins are called _______.
chromatids
chromosomes
genes
traits

99. Chapter 10
Sexual Reproduction and Genetics
10.1 Formative Questions
3. What is the term for a pair of chromosomes that have the same length, same centromere position, and carry genes that control the same traits?
diploid
heterozygous
homozygous
homologous

100. A. Gametes have 1/4 the number of chromosomes.
Chapter 10
Sexual Reproduction and Genetics
10.1 Formative Questions
4. How does the number of chromosomes in gametes compare with the number of chromosomes in body cells?
A. Gametes have 1/4 the number of chromosomes.
B. Gametes have 1/2 the number of chromosomes.
C. Gametes have the same number of chromosomes.
D. Gametes have twice as many chromosomes

101. 5. Which stage of meiosis is illustrated?
Chapter 10
Sexual Reproduction and Genetics
Chapter Assessment Questions
5. Which stage of meiosis is illustrated?
prophase I
interphase
anaphase I
anaphase II

102. 6. What is the next step for the chromosomes illustrated?
Chapter 10
Sexual Reproduction and Genetics
Chapter Assessment Questions
6. What is the next step for the
chromosomes illustrated?
Chromosomes replicate.
Chromosomes move to opposite poles.
Chromosomes uncoil and form two nuclei.
Chromosomes line up at the equator.

103. 7. Before meiosis I, the sister chromatids
Chapter 10
Sexual Reproduction and Genetics
Standardized Test Practice
7. Before meiosis I, the sister chromatids
of this chromosome were identical.
What process caused a change in a
section of one chromatid?
DNA replication
crossing over
synapsis
telophase

104. 8. At what stage is the chromosome number reduced from 2n to n?
Chapter 10
Sexual Reproduction and Genetics
Standardized Test Practice
8. At what stage is the chromosome
number reduced from 2n to n?
prophase I
metaphase I
anaphase I
meiosis II

105. 9. What is this process called?
Chapter 10
Sexual Reproduction and Genetics
Standardized Test Practice
9. What is this process called?
fertilization
gamete formation
inheritance
reproduction

106. 10. How many chromosomes would a cell
Chapter 10
Sexual Reproduction and Genetics
Chapter Assessment Questions
10. How many chromosomes would a cell
have during metaphase I of meiosis if it
has 12 chromosomes during interphase? 6 12 24 36

107. Chapter 10
Sexual Reproduction and Genetics
10.3 Formative Questions
True or False
11. Two genes on the same chromosome may become separated during meiosis.

108. 12. What type of organisms only reproduce asexually?
Chapter 10
Sexual Reproduction and Genetics
10.1 Formative Questions
12. What type of organisms only reproduce asexually?
bacteria
protists
plants
simple animals

109. 13. Name the person known as the father of genetics.
Chapter 10
Sexual Reproduction and Genetics
10.2
13. Name the person known as the father
of genetics.
Felix Mendelssohn
Gregor Mendel
Dr. Reginald Punnett
Albert Einstein

110. 14. Which term refers to the outward expression of an allele pair?
Chapter 10
Sexual Reproduction and Genetics
Chapter Diagnostic Questions
14. Which term refers to the outward
expression of an allele pair?
gamete
hybrid
phenotype
genotype

111. Chapter 10
Sexual Reproduction and Genetics
10.2 Formative Questions
15. What is the name for different forms of a single gene that are passed from generation to generation?
alleles
genotypes
phenotypes
traits

112. 16. Which pair of alleles is heterozygous?
Chapter 10
Sexual Reproduction and Genetics
10.2 Formative Questions
16. Which pair of alleles is heterozygous? RR Rr rr yR

113. To which step in this process does the law of segregation apply?
Chapter 10
Sexual Reproduction and Genetics
To which step in this process does the law of segregation apply?
grows into plant
gamete formation
fertilization
seed development

114. 1/4 1/2 1 18. For human eye color, brown is dominant and
Chapter 10
Sexual Reproduction and Genetics
Standardized Test Practice
18. For human eye color, brown is dominant and
blue is recessive. If a husband is
heterozygous and his wife has blue eyes,
what is the probability that their child will
have blue eyes?
1/4
1/2 1

115. Chapter 10
Sexual Reproduction and Genetics
10.2 Formative Questions
19.. In rabbits, gray fur (G) is dominant to black fur (g). If a heterozygous male is crossed with a heterozygous female, What is the phenotypic ratio of the possible offspring?
1:1
1:2:1
2:1
3:1

116. genetic recombination independent segregation
Chapter 10
Sexual Reproduction and Genetics
10.3
20. Which explains how the shuffling of genes during meiosis results in billions of possible combinations?
crossing over
gene linkage
genetic recombination
independent segregation

117. Chapter 10
Sexual Reproduction and Genetics
10.3 Formative Questions
21. What is the term for an organism that has one or more sets of extra chromosomes in its cells?
diploid
gamete
hybrid
polyploid

118. Glencoe Biology Transparencies
Chapter 10
Sexual Reproduction and Genetics
Glencoe Biology Transparencies

119. Chapter 10
Sexual Reproduction and Genetics
Image Bank

120. Chapter 10
Sexual Reproduction and Genetics
Image Bank

121. Section 1 Vocabulary gene homologous chromosome gamete haploid
Chapter 10
Sexual Reproduction and Genetics
Vocabulary
Section 1
gene
homologous chromosome
gamete
haploid
fertilization
diploid
meiosis
crossing over

122. Section 2 Vocabulary genetics allele dominant recessive homozygous
Chapter 10
Sexual Reproduction and Genetics
Vocabulary
Section 2
genetics
allele
dominant
recessive
homozygous
heterozygous
genotype
phenotype
law of segregation
hybrid
law of independent assortment

123. Section 3 Vocabulary genetic recombination polyploidy Chapter 10
Sexual Reproduction and Genetics
Vocabulary
Section 3
genetic recombination
polyploidy

124. Visualizing Meiosis I and Meiosis II Generations
Chapter 10
Sexual Reproduction and Genetics
Animation
Visualizing Meiosis I and Meiosis II
Generations