section 10.1 - mendel’s law of...
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Ch 10: Mendel and Meiosis
Section 10.1 - Mendel’s Law of Heredity
Section 10.1
Who is Gregor Mendel
Mendel’s Crosses
Phenotypes and Genotypes
Probability in Genetics
Inside This Section...
Known as the father of _________ _________
Developed the principles of heredity by studying the variation and heredity of seven pairs of inherited characteristics in ______________.
The significance of his work was not recognized during his lifetime.
Who is Gregor Mendel?
Section 10.1
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Genetics is the branch of biology that studies _________
Heredity is the passing of __________________ from parents to offspring
_______ are inherited characteristics
Genetics
Section 10.1
_________ are the sex cells that allow an organism to reproduce
A _______ is the offspring of parents who have different traits
More Definitions
Section 10.1
Both male and female parts on the same flower
Male gamete is in the _______ ______
Female gamete is in the ______ (located in the pistil)
Reproduction in Peas
Section 10.1
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Pollination is the transfer of male pollen grains to the _____
______________ happens when the male and female gametes unite
Reproduction in Peas
Section 10.1
The Generations
Parental (P) Generation
F2 Generation
F1 Generation
Section 10.1
Each organism has _____ factors that control each trait
These factors are called genes and are found on the chromosomes and have ___________ forms
The different gene forms that control one trait are called ________
The Rule of Factors
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Alleles and Genes
Section 10.1
__________: The trait that is more expressive in alleles than other traits (represented by a capital letter)
___________: The trait that is submissive in the alleles to the other traits. (Represented by a lowercase letter)
If an organism contains a dominant and a recessive allele, the __________ trait will be expressed
The Rule of Dominance
TT or Tt tt
Section 10.1
____________ is the physical expression of an organism genes
___________ is the genetic makeup of an organism
The Rule of Dominance
TT or Tt tt
Section 10.1
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Alleles separate during ________
Each new cell gets one allele for each ______
The Law of Segregation
TT or Tt tt
Section 10.1
All traits are inherited ________________ from each other
The Law of Independent assortment
Section 10.1
______________ Cross: A cross in which ALL traits are identical except one
_________ Cross: A cross in which two traits differ between organisms
Two types of Crosses
Section 10.1
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Mendel’s Monohybrid Cross
P: Parental GenerationF1- All TallF2 - 3 tall : 1 short
When Mendel crossed tall pea plants with short ones, the first generation (F1) consisted of all _____ plants
When he crossed the F1 generation, ____ of the F2 generation were tall and _____ were short
Section 10.1
The Punnett Square
Named after Reginald Punnett
Useful for making offspring ______________
Alleles for 1 parent placed at the top and for the other at the left
Each box is filled with the _______ to the top and to the left
T
T t
t
TT
tt
TT tt
Section 10.1
Mendel’s Dihybrid CrossWhen Mendel crossed Round Yellow peas with wrinkled green peas, all of the F1 generation were _______________ Peas
In the F2 generation, the following ratios were found:
__ Round Yellow
__ Round Green
__ Wrinkled Yellow
__ Wrinkled Green
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Mendel’s Dihybrid CrossRrYy * RrYy
rryyrrYyRryyRrYy
rrYyrrYYRrYyRrYY
RryyRrYyRRyyRRYy
RrYyRrYYRRYyRRYY
RY Ry rY ry
RY
Ry
rY
ry
Probability & Genetics
Section 10.1
Who is Gregor Mendel
Mendel’s Crosses
Phenotypes and Genotypes
Probability in Genetics
In Review...
Section 10.1
Ch 9: Energy in a Cell
Section 10.2 - Meiosis
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The Two Types of Cells
Chromosomes and Genes
What is Meiosis?
Genetic Recombination
Inside This Section...
Section 10.2Section 10.2
Section 10.2
________: A cell with two of each kind of Chromosomes (both alleles for each gene)
We signify this by writing ”___”
All cells in the body except sex cells are diploid
Two Types of Cells_________: A cell with one of each kind of Chromosome (only one allele for each gene)
We signify this by writing ”__”
Sex cells are Haploid
Section 10.2
Chromosomes usually have about a thousand or more ______
Chromosomes occur in ________ (______________ chromosomes)
Each chromosome has one allele for a particular gene
Each species contains a characteristic number of _______________
Chromosomes and Genes
Section 10.2
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Number of Chromosomes
Chromosome Numbers of Some Common OrganismsChromosome Numbers of Some Common OrganismsChromosome Numbers of Some Common Organisms
Organism Body Cell (2n) Gamete (n)
Fruit fly 8 4
Garden pea 14 7
Corn 20 10
Tomato 24 12
Leopard frog 26 13
Apple 34 17
Human 46 23
Chimpanzee 48 24
Dog 78 39
Adder’s tongue fern 2360 630
Section 10.2
A Process of cell division that results in the production of sex cells (_________)
Consists of
_____________: Cell replicates chromosomes
___________: Results in 2 haploid cells
___________ (similar to mitosis): Results in 4 haploid cells
What is Meiosis?
Section 10.2
Meiosis
Section 10.2
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Prophase I
Homologous chromosomes come together and form a _______ (four-part structure)
Sometimes chromosomes exchange genetic material in a process called ___________ ________
Meiosis I
Section 10.2
Section 10.2
Crossing Over
Section 10.2
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Metaphase I
Spindle fibers cause Homologous Chromosomes to line up side by side at the equator (___________________)
Meiosis I
Section 10.2
Section 10.2
Anaphase I
Homologous chromosomes separate making each new cell _________
Meiosis I
Section 10.2
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Section 10.2
Telophase I
Reversal of Prophase I
Spindle breaks down, chromosomes uncoil, ____________ divides
Meiosis I
Section 10.2
Section 10.2
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Identical to Mitosis
Results in ___________ cells
Meiosis II
Section 10.2
Section 10.2
Genetic recombination is the source of variation. This is caused by the re-assortment or crossing over during meiosis
7 pairs of chromosomes = 27 = 128 combinations
Any egg can be fertilized by any sperm, so 128 x 128 = 16,384 possibilities
N=23, 223 = 8,388,608 possibilities
8,388,608 x 8,388,608 = 7 Trillion possibilities
Crossing over is the exchange of genetic material during prophase I, which results in new combinations of Alleles
Genetic Recombination
Section 10.2
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The Two Types of Cells
Chromosomes and Genes
What is Meiosis?
Genetic Recombination
In Review...
Section 10.2
Ch 9: Energy in a Cell
Section 10-3: Mistakes in meiosis
Section 10.3
Nondisjunction
Triploidy and Polyploidy
Inside This Section...
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When chromosomes fail to __________ during meiosis.
_________: When one gamete gets an extra chromosome, causing the other gamete to be short by one (e.g. Down’s syndrome - trisomy 21)
__________: When one gamete lacks one chromosome
Nondisjunction
Section 10.3
Triploid is a total lack of ______________ of homologous chromosomes.
Polyploids are organisms that have more than the normal amount of chromosomes
Rare in _________ usually causing death
Frequently occurs in _______ causing fruit and flowers to be larger
Triploidy and Polyploidy
Section 10.3
In Review...
Section 10.3
Nondisjunction
Triploidy and Polyploidy
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