Cross In a cross need to know first the terms used. Terms in the crosses can you understand the following description. Parietal (P), meaning the parent or parents. Filial (F), means descent. ☯ first offspring (F1) = Child ☯ second offspring (F2) = grandchildren Genotype is the properties of decline that is not visible from the outside, is symbolized by a couple of letters.
Example: AA, Aa, aa, AABB, and the AABB. Gametes are sex cells and derived from genotype. Example: genotype Aa, gametnya A and a. Phenotype is characteristic decreases visible from the outside.
Example: large fruit, small fruit, sweetness, sourness, tall stem and short stem. Dominant traits or genes that always seem to appear, symbolized by capital letters. Example: AA, BB, and CC. Gene is recessive gene traits that are not always apparent when the newly emerged together another recessive gene, symbolized by small letters.
Examples: aa, bb, and cc. Is homozygous gene pair of the same nature. Example: AA, AA, BB, bb, CC, and cc. Heterozygous is not the same gene pair. Example: Aa, Bb, and Cc.
Monohibrid
Monohybrid cross is a cross between two conspecifics by observing a different nature.
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| Monohibrid |
Crosses between each other can be depicted in diagrammatic form. The diagram is known as a Punnett diagram.
Do you know the shape of the diagram punnet?
Diagram punnet rhombic or may be horizontal as Figure beside.
You may notice the following example to better understand it.
Example
Large mango fruit with genotype Bb crossed with a small fruiting mango bb genotype. Great fruit dominant over smaller fruit.
Determine the ratio of genotype and phenotype F1 F1.
Given: P (parietal) = Bb and bb
B = Great Fruit
b = small fruit
Asked: F1 genotype and phenotype F1.
answer
P (parent): Bb x bb
Great fruit small fruit
Gamet: b, b b
F1 (offspring to-1):
Phenotype F2: Round seed And Brass colored, round green beans, yellow-colored beans shriveled, wrinkled green seeds.
You may notice the following example to better understand it.
Example
Large mango fruit with genotype Bb crossed with a small fruiting mango bb genotype. Great fruit dominant over smaller fruit.
Determine the ratio of genotype and phenotype F1 F1.
Given: P (parietal) = Bb and bb
B = Great Fruit
b = small fruit
Asked: F1 genotype and phenotype F1.
answer
P (parent): Bb x bb
Great fruit small fruit
Gamet: b, b b
F1 (offspring to-1):
B
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b
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b
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Bb
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bb
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F1 (offspring to-1):
Comparison of genotype F1 = Bb: bb 1: 1
In monohybrid cross there is a test cross and nature of the intermediates. What do you know about the test cross and nature of the intermediates? You may notice the following descriptions to understand it more.
a. Test Cross
Test cross is the crossing of individuals who want to know the genotype with a homozygous recessive genotype individuals. The result of this cross has two possibilities as follows.
1) If the plant is crossed with a plant of genotype BB bb genotype (homozygous recessive), it will produce offspring genotype Bb everything. With B = round, b = wrinkles. So, all the offspring had round seeds.
P (parent): × BB bb
Garmet: B and B
F1 (offspring to-1)
B
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b
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Bb
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Genotype F1: Bb
Thus, the resulting offspring Bb.
2) If the plant is crossed with a plant of genotype Bb bb genotype (homozygous recessive), it will produce offspring genotype Bb and bb. Try to note the decrease in the nature of heredity below.
P (parent): Bb x bb
Garmet: B, B and B
F1 (offspring to-1)
Genotype F1: Bb and bb
So, there is unanimous and there are seed plants seed plants wrinkled.
Based on tests conducted by Mendel cross, you can know that the spherical nature of (B) is dominant over the nature of wrinkles (b) so that individuals of genotype Bb has a rounded phenotype and genotype individuals berfenotipe round is BB and Bb.
b. nature of intermediates
Intermediates nature is influenced by a dominant gene that is not saturated. As performed by Mendel on the red flowering plants Antirrhinum wise pure lines (MM) crossed with white magi Antirrhinum pure strain (mm).
The results obtained by Mendel descendant is wise that berfenotipe Antirrhinum pink, not red though genotype Mm. Try to note the decrease in properties below.
P (parent): MM × mm
Gametes: M and m
F1 (offspring to-1)
M
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m
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Mm
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Genotype F1: Mm
If F1 were crossed with each other it is obtained:
P (parent): Mm Mm ×
Gamet: M, M and M, m
F2 (offspring 2nd)
M
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Mm
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M
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MM
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Mm
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m
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Mm
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mm
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F1 genotypes: MM, 2 Mm, mm
Phenotype: Red, pink, white
In the previous description, it appears that plants with flowers in pink, mated with tanamanbunga white, will produce one plant with flowers in pink without bringing whiteness, two plants with flowers in pink, but bring whiteness, and one plant color white.
dihybrid cross
You learn about monohybrid cross, whether monohybrid cross together with dihybrid? What do you know about dihybrid cross? Try to learn the following explanation.
Dihybrid cross is a cross of two conspecifics by observing two different properties. Mendel has experimented with crossing peas pure strains that have two different properties, namely the pea seed in round yellow (BBKK) with wrinkled pea seed in green (BBKK). Both the nut has two different properties, namely the shape and color of seeds.
Can you determine the result of a cross of these two peas? Try to learn a decrease in the nature of pea seed in round yellow (BBKK) with wrinkled pea seed in green (BBKK) below.
P (parent): BBKK × BBKK
Gametes: BK and bk
F1 (offspring to-1)
Genotype F1: BBKK
Phenotype F1: Seeds are round and yellow
If the genotype of F1 crossed each other, the result is:
P (parent): BBKK × BBKK
Gamet: BK, Bk, bK, bk and BK, Bk, bK, bk
F2 (offspring 2nd)
Genotipe F2: BBK, BBK, BBK, BBK, 2BBKk, 2BbKK, 4BbKk, 2Bbkk, 2bbKk
Phenotype F2: Round seed And Brass colored, round green beans, yellow-colored beans shriveled, wrinkled green seeds.
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