Principles of Inheritance and Variation

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Mendel's Laws of Inheritance

$(1/2T + 1/2t)^2 = 1/4 TT + 1/2 Tt + 1/4 tt$

This formula represents the genotypic ratio in a monohybrid cross.

Terms:

Dominant allele for tallness

Recessive allele for dwarfness

Mendel's laws include the Law of Dominance, Law of Segregation, and Law of Independent Assortment, which explain how traits are inherited through generations.

Common Use:

Used to predict the outcome of genetic crosses.

Practice Related Questions

Genetics

Inheritance

Mendel

1 of 5.

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Practice Questions

NEET Questions

1. Fruit colour in squash is an example of

2. A man whose father was color blind marries a woman who had a color-blind mother and normal father. What percentage of their male children will be color-blind?

3. In a population of 1000 individuals, 360 belong to genotype AA, 480 to Aa, and the remaining 160 to aa. Based on this data, the frequency of allele A in the population is

4. A human female with Turner’s syndrome

5. A man with blood group ‘A’ marries a woman with blood group ‘B’. What are all the possible blood groups of their offspring?

6. How many pairs of contrasting characters in pea plants were studied by Mendel in his experiments?

7. The movement of a gene from one linkage group to another is called

8. Multiple alleles are present

9. Which is the most common mechanism of genetic variation in the population of a sexually reproducing organism?

10. A somatic cell that has just completed the S phase of its cell cycle, as compared to a gamete of the same species, has

11. Alleles are

12. An abnormal human baby with ‘XXX’ sex chromosomes was born due to

13.

In context of amniocentesis, which of the following statement is incorrect?

14.

A tall true breeding garden pea plant is crossed with a dwarf true breeding garden pea plant. When the F₁ plants were selfed, the resulting genotypes were in the ratio of

15. Match the terms in Column I with their description in Column II and choose the correct option.

16.

Pick out the correct statements $\\ (a)$ Haemophilia is a sex-linked recessive disease. $\\ (b)$ Down’s syndrome is due to aneuploidy. $\\ (c)$ Phenylketonuria is an autosomal recessive gene disorder. $\\ (d)$ Sickle cell anaemia is an X-linked recessive gene disorder.

17.

In a testcross involving F $_1$ dihybrid flies, more parental-type offspring were produced than the recombinant-type offspring. This indicates

18.

Which of the following most appropriately describes haemophilia?

19. Among the following characters, which one was not considered by Mendel in his experiments on pea?

20. Homozygous purelines in cattle can be obtained by

21. A disease caused by an autosomal primary non-disjunction is

22. Thalassemia and sickle cell anemia are caused due to a problem in globin molecule synthesis. Select the correct statement.

23.

The genotypes of a husband and wife are $I^{A}I^{B} and I^{A}i.$ Among the blood type of their children, how many different genotypes and phenotypes are possible?

24. Which one from those given below is the period for Mendel’s hybridization experiments?

25.

Select the correct match:

26.

Which of the following pairs is wrongly matched?

27.

Select the correct statement:

28.

Select the correct match:

29.

Which of the following features is used to identify a male cockroach from a female cockroach?

30.

A woman has an X-linked condition on one of her X chromosomes. This chromosome can be inherited by

31.

Select the incorrect match:

32.

Which of the following characteristics represent ‘Inheritance of blood groups’ in humans? $\newline$ a. Dominance $\newline$ b. Co-dominance $\newline$ c. Multiple allele $\newline$ d. Incomplete dominance $\newline$ e. Polygenic inheritance

33. Variations caused by mutation, as proposed by Hugo de Vries, are:

34. Select the incorrect statement.

35. Select the incorrect statement.

36. What map unit (Centimorgan) is adopted in the construction of genetic maps?

37. In Antirrhinum (Snapdragon), a red flower was crossed with a white flower and in F1 generation pink flowers were obtained. When pink flowers were selfed, the F2 generation showed white, red, and pink flowers. Choose the incorrect statement from the following:

38. A gene locus has two alleles A, a. If the frequency of dominant allele A is 0.4, then what will be the frequency of homozygous dominant, heterozygous, and homozygous recessive individuals in the population?

39. The frequency of recombination between gene pairs on the same chromosome as a measure of the distance between genes was explained by:

40. What is the genetic disorder in which an individual has an overall masculine development, gynecomastia, and is sterile?

41. The shorter and longer arms of a submetacentric chromosome are referred to as

42.

Experimental verification of the chromosomal theory of inheritance was done by:

43.

Select the correct match.

44.

How many true breeding pea plant varieties did Mendel select as pairs, which were similar except in one character with contrasting traits?

45.

By which method was a new breed ‘Hisardale’ of sheep formed by using Bikaneri ewes and Marino rams?

46.

Identify the wrong statement with reference to the gene ‘I’ that controls ABO blood groups.

47.

The production of gametes by the parents, formation of zygotes, the $F_1$ and $F_2$ plants, can be understood from a diagram called:

48.

Mutations in plant cells can be induced by:

49. In a cross between a male and female, both heterozygous for sickle cell anaemia gene, what percentage of the progeny will be diseased?

50.

Given below are two statements: $\newline$ $\newline$ Statement I: Mendel studied seven pairs of contrasting traits in pea plants and proposed the Laws of Inheritance. $\newline$ $\newline$ Statement II: Seven characters examined by Mendel in his experiment on pea plants were seed shape and colour, flower colour, pod shape and colour, flower position and stem height. $\newline$ $\newline$ In the light of the above statements, choose the correct answer from the options given below:

51. The appearance of recombination nodules on homologous chromosomes during meiosis characterizes:

52. XO type of sex determination can be found in:

53. Which of the following occurs due to the presence of an autosome-linked dominant trait?

54.

$\newline$ Given below are two statements: $\newline$ $\newline$ Assertion (A): Mendel’s law of independent assortment does not hold good for the genes that are located closely on the same chromosome. $\newline$ Reason (R): Closely located genes assort independently. $\newline$ $\newline$ In the light of the above statements, choose the correct answer from the options given below:

55. Match List-I with List-II:

56. The recombination frequency between the genes a & c is 5%, b & c is 15%, b & d is 9%, a & b is 20%, c & d is 24%, and a & d is 29%. What will be the sequence of these genes on a linear chromosome?

57. If a color-blind female marries a man whose mother was also color-blind, what are the chances of her progeny having color blindness?

58.

The phenomenon of pleiotropism refers to

59.

Frequency of recombination between gene pairs on the same chromosome as a measure of the distance between genes to map their position on chromosome, was used for the first time by

60.

Which of the following statements are correct about Klinefelter's Syndrome? $\newline$ A. This disorder was first described by Langdon Down (1866). $\newline$ B. Such an individual has overall masculine development. However, the feminine development is also expressed. $\newline$ C. The affected individual is short statured. $\newline$ D. Physical, psychomotor and mental development is retarded $\newline$ E. Such individuals are sterile. $\newline$ Choose the correct answer from the options given below:

61.

Broad palm with a single palm crease is visible in a person suffering from:

62.

Which one of the following symbols represents mating between relatives in human pedigree analysis?

63.

Which of the following is NOT an advantage of inbreeding?

64.

Which of the following is a characteristic feature of cockroach regarding sexual dimorphism?

65.

Which one of the following can be explained on the basis of Mendel’s Law of Dominance? $\newline$ A. Out of one pair of factors one is dominant and the other is recessive. $\newline$ B. Alleles do not show any expression and both the characters appear as such in F_2 generation. $\newline$ C. Factors occur in pairs in normal diploid plants. $\newline$ D. The discrete unit controlling a particular character is called factor. $\newline$ E. The expression of only one of the parental characters is found in a monohybrid cross.

66.

$\newline$ Given below are two statements: $\newline$ $\newline$ Statement I: Chromosomes become gradually visible under light microscope during leptotene stage. $\newline$ $\newline$ Statement II: The beginning of diplotene stage is recognized by dissolution of synaptonemal complex. $\newline$ $\newline$ In the light of the above statements, choose the correct answer from the options given below: