In Lathyrus odoratus , what does the F 1 ratio of 9 : 7 represent in phenotypes in flower colours?

Complementary genes are a type of gene interaction between two alleles (or gene versions) of two different genes that work together to create a specific phenotype or visible trait. For example, complementary genes help control the colour of the flower in sweet pea plants ( Lathyrus odoratus ). In case of Lathyrus odoratus the phenotypic ratio is 9 : 7 instead of 9:3:3:1. 9 represents purple flowers and 7 represents white flowers.

In Lathyrus odoratus , what does the F 1 ratio of 9 : 7 represent in phenotypes in flower colours?

Complementary genes are a type of gene interaction between two alleles (or gene versions) of two different genes that work together to create a specific phenotype or visible trait. For example, complementary genes help control the colour of the flower in sweet pea plants ( Lathyrus odoratus ). In case of Lathyrus odoratus the phenotypic ratio is 9 : 7 instead of 9:3:3:1. 9 represents purple flowers and 7 represents white flowers.

Match the genetic phenomena with their respective ratios a Inhibitory gene ratio 1 9 : 3 : 4 b Complementary gene ratio 2 1 : 1 : 1 : 1 c Recessive epistasis ratio 3 12 : 3 : 1 d Dihybrid test cross ratio 4 13 : 3 e Dominant epistasis ratio 5 9 : 7 *Note: The question has been modified here as it was incorrect in book.

a - 4 , b - 5 , c - 1 , d - 2 , e - 3

a - 5 , b - 4 , c - 3 , d - 2 , e - 1

a - 1 , b - 2 , c - 4 , d - 3 , e - 5

a - 2 , b - 1 , c - 4 , d - 5 , e - 3

Identify the correct match in column I and column II: Column I Column II A Dominant epistasis i 9 : 3 : 4 B Recessive epistasis ii 15 : 1 C Complementary genes iii 12 : 3 : 1 D Duplicate genes iv 9 : 7

A → ( iii ) , B → ( i ) , C → ( iv ) , D → ( ii )

A → ( iii ) , B → ( ii ) , C → ( i ) , D → ( iv )

A → ( iii ) , B → ( iv ) , C → ( i ) , D → ( ii )

A → ( ii ) , B → ( iii ) , C → ( iv ) , D → ( i )

Match Column I and Column II: Column I Column II A Dominant epistasis i 9 : 3 : 4 B Recessive epistasis ii 15 : 1 C Complementary genes iii 12 : 3 : 1 D Duplicate genes iv 9 : 7

A → ( iii ) , B → ( i ) , C → ( iv ) , D → ( ii )

A → ( iii ) , B → ( ii ) , C → ( i ) , D → ( iv )

A → ( iii ) , B → ( iv ) , C → ( i ) , D → ( ii )

A → ( ii ) , B → ( iii ) , C → ( iv ) , D → ( i )

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In Lathyrus odoratus, what does the F₁ratio of 9 : 7 represent in phenotypes in flower colours?

Important Questions on Principles of Inheritance and Variation

EASY

Biology>Genetics and Evolution>Principles of Inheritance and Variation>Deviations from Mendelism

In a diploid organism, when the locus X is inactivated by locus Y, transcription of the locus Y is triggered. Based on this observation, which one of the following statements is CORRECT?

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Biology>Genetics and Evolution>Principles of Inheritance and Variation>Deviations from Mendelism

Define polygenic inheritance.

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Biology>Genetics and Evolution>Principles of Inheritance and Variation>Deviations from Mendelism

A woman with blood group O married a man with blood group AB. Show the possible blood groups of the progeny. List the alleles involved in this inheritance.

EASY

Biology>Genetics and Evolution>Principles of Inheritance and Variation>Deviations from Mendelism

In a diploid organism, when the locus

X

is inactivated, transcription of the locus

Y

is triggered. Based on observation. Which one of the following statements is CORRECT?

MEDIUM

Biology>Genetics and Evolution>Principles of Inheritance and Variation>Deviations from Mendelism

Match the genetic phenomena with their respective ratios

$a$	Inhibitory gene ratio	$1$	$9 : 3 : 4$
$b$	Complementary gene ratio	$2$	$1 : 1 : 1 : 1$
$c$	Recessive epistasis ratio	$3$	$12 : 3 : 1$
$d$	Dihybrid test cross ratio	$4$	$13 : 3$
$e$	Dominant epistasis ratio	$5$	$9 : 7$

*Note: The question has been modified here as it was incorrect in book.

MEDIUM

Biology>Genetics and Evolution>Principles of Inheritance and Variation>Deviations from Mendelism

Which option is correct for this matching?

Column I	Column II
I. Supplementary gene	A. The gene which suppresses genes the expression of a non-allelic
II. Complementary genes	B. Gene controlling the expression of two or more characters in a dominant state
III. Epistatic gene	C. Pair of non-allelic genes where only one is able to express its effect independently in a dominant state
IV. Pleiotropic gene	D. Pair of non-allelic genes, both of which independently express similar phenotypes

MEDIUM

Biology>Genetics and Evolution>Principles of Inheritance and Variation>Deviations from Mendelism

Which of the following genotype of sweet pea plant is related with the production of purple coloured flowers?

EASY

Biology>Genetics and Evolution>Principles of Inheritance and Variation>Deviations from Mendelism

If dominant alleles of two gene loci produce the same phenotype whether inherit separately or together, it will be

EASY

Biology>Genetics and Evolution>Principles of Inheritance and Variation>Deviations from Mendelism

In a cross between white-flowered parents, F₁ progeny was uniformly purple-flowered. The F₂progeny showed a phenotypic ratio 9 : 7 between purple-flowered and white-flowered plants. The above result indicates that the flower colour is controlled by:

MEDIUM

Biology>Genetics and Evolution>Principles of Inheritance and Variation>Deviations from Mendelism

Identify the correct match in column I and column II:

Column I		Column II
A	Dominant epistasis	i	$9 : 3 : 4$
B	Recessive epistasis	ii	$15 : 1$
C	Complementary genes	iii	$12 : 3 : 1$
D	Duplicate genes	iv	$9 : 7$

MEDIUM

Biology>Genetics and Evolution>Principles of Inheritance and Variation>Deviations from Mendelism

Gene which suppresses other gene's activity but does not lie on the same locus is called as

MEDIUM

Biology>Genetics and Evolution>Principles of Inheritance and Variation>Deviations from Mendelism

Lathyrus odoratus is an example of which of the following genes

MEDIUM

Biology>Genetics and Evolution>Principles of Inheritance and Variation>Deviations from Mendelism

Genes that are similar in phenotypic effect when present separately, but together interact to produce a different trait give a ratio of

9 : 7

in the

F_{2}

generation. What are such genes known as?

MEDIUM

Biology>Genetics and Evolution>Principles of Inheritance and Variation>Deviations from Mendelism

Statement-1: An example of intergenic inheritance is recessive epistasis.
Statement-2: Coat colour in mouse develops due to intergenic interaction.

EASY

Biology>Genetics and Evolution>Principles of Inheritance and Variation>Deviations from Mendelism

In Cucurbita,

W

is epistatic over

Y

and

y

gene normally responsible for yellow and green colour fruits. It produces white fruits. What is the ratio of fruits in the progeny of cross

Ww Yy \times wwYy ?

HARD

Biology>Genetics and Evolution>Principles of Inheritance and Variation>Deviations from Mendelism

In sweet peas, genes C and P are necessary for colour in flowers. The flowers are white in the absence of either or both the genes. What will be the percentage of coloured flowers in the offspring of the cross Ccpp × ccPp?

HARD

Biology>Genetics and Evolution>Principles of Inheritance and Variation>Deviations from Mendelism

A gene has two alleles B and b. B is responsible for the expression of character x. b is responsible for the expression of character y. B is completely dominant over b. Another gene A is epistatic on gene B. When A is in the dominant condition it suppresses the expression of B and b and gives rise to character z. In recessive condition (allele a) allows expression of B and b. When an organism with genotype AaBb is crossed with another organism with genotype AbBb, the ratio of characters x, y and z seen in its offsprings is

HARD

Biology>Genetics and Evolution>Principles of Inheritance and Variation>Deviations from Mendelism

Match Column I and Column II:

Column I		Column II
A	Dominant epistasis	i	$9 : 3 : 4$
B	Recessive epistasis	ii	$15 : 1$
C	Complementary genes	iii	$12 : 3 : 1$
D	Duplicate genes	iv	$9 : 7$

HARD

Biology>Genetics and Evolution>Principles of Inheritance and Variation>Deviations from Mendelism

Match the following Column I with Column II.

Column – I	Column – II
A. Complementary ratio	1. 9 : 7
B. Supplementary ratio	2. 9 : 3 : 4
C. Epistatic ratio (Masking)	3. 12 : 3 : 1
D. Inhibitory ratio	4. 13 : 3

MEDIUM

Biology>Genetics and Evolution>Principles of Inheritance and Variation>Deviations from Mendelism

The gene which increases the frequency of mutation in other gene is referred to as

In Lathyrus odoratus, what does the F1 ratio of 9 : 7 represent in phenotypes in flower colours?

Important Questions on Principles of Inheritance and Variation

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In Lathyrus odoratus, what does the F₁ratio of 9 : 7 represent in phenotypes in flower colours?