2nd Year Biology Chapter 22 Variation and Genetics Notes

biology 12th notes chapter 22

1. Mendel’s idea that pairs of characters separate during gamete formation is called the law of


2. Achondroplasia is a dominant form of dwarfism.What is the chance of having an unaffected child from two.


3. Using the symbols provided below, what is the genotype of a heterozygous tall, homozygous green pod pea plant?


4. When round wrinkle were crossed, it gave all round.This round is


5. Which of the followings is not multiple allele?


6. In AB blood group IAI B is


7. The results of Mendelian F1 were all


8. Different alleles of the gene that are both expressed in heterozygous condition are called:


9. The law of segregation gives phenotypic ratio in F2 as


10. In humans, brown eyes is dominant to blue eyes .A brown eyed man marries a blue eyed woman.The possible eye colours of their children are


11. What is the major value in using a Punnett square?


12. Total genes found in a population is


13. Mendel’s law of segregation states that


14. The branch of Biology dealing with the principles that explain the similarities between parents and their progeny and differences among individuals of a species


15. Haemophillia is


16. The blood group without antibody is


17. In F3 cross the round producing only round were


18. Using the symbols provided below, what is the genotype of a heterozygous tall, heterozygous green pod pea plant?


19. Which phenomenon reduces the chances of genetic recombination and variations among Offspring


20. In test cross if the parent whose genotypes is to be determined is heterozygous then it gives


21. Approximately how many human single-gene traits and illnesses are currently known from medical reports?


22. In F3 cross the 2/3 round produce


23. Different alleles of a gene that are both expressed in a heterozygous condition are called


24. When a single gene has multiple phenotypic effects, the phenomenon is called:


25. Consider a group of 100 individuals , all of whom carry a recessive disease allele.If 200 children were born to these couples, what percentage of the children would, theoretically, be carriers like their parents?


26. Two carriers of albinism have four children.One of their children is albino and the remaining three are normally pigmented.What is the probability that their next child will be albino?


27. The work of Mendel remained neglected for


28. The cross used to determine the genotype is called


29. If an organism with the genotype Ww is crossed with a Ww organism, what would be the proportion of offspring that would be heterozygous?


30. Human skin color is controlled by gene pairs


31. Female and male sex cells are called


32. The trait found in 1/4 of F2 was


33. Match beanbag genetics with one of the followings


34. ABO blood group system was discovered by


35. In F3 cross the 2/3 round give ratio of


36. The allele that masks the effects of the other and the masked allele are known as


37. MN blood group system is example of;


38. Bleed group ‘A’ can be transfused only into


39. Which of the following Mendelian characters is mismatched?


40. The genetic basis of ABO blood group system was discovered by


41. Match elementon of Mendel with one of the followings


42. The Individual called universal recipients has


43. The genetic complement of an individual is called


44. Mendel selected pea because it is naturally


45. Who for the first time found white eye mutant in Drosophila?


46. Which rule of probability is useful in calculating the risk that certain individuals will inherit a particular genotype?


47. When a haemophilic carrier woman marries a normal man, who among her offspring may be affected.


48. The work of Mendel was rediscovered after how many years of his death is?


49. Law of segregation suggests that each gametes has


50. The form of appearance of trait is


51. Why was Mendel fairly certain that he had a pure-bred variety when he collected seeds from a pea plant?


52. The occurrence of affected individuals in every generation in a family suggests which of these traits?


53. When tall is crossed with dwarf, F1 gives tall, it is


54. Which of the following traits is not sex-linked recessive?


55. What is the risk of a color-blind child in a family when father is color-blind but mother is normal?


56. In the cross AaBbaabb, what percentage of the offspring are expected to show a completely dominant phenotype?


57. Which of the following traits is not sex- linked recessive?


58. Which of the following crosses is a test cross?


59. Which of the following incorrectly identifies the mode of inheritance for the given genetic disease?


60. If a man with blood group M marries with woman N, the offspring will be


61. All the alternative form of a gene, whose number is more than two are called:


62. True breeding variety is


63. Which of the following scientists rediscovered the work of Mendel?


64. What is the risk of a color-blind child in a family when mother is color-blind but father is normal?


65. Any group of inter breeding organisms of the same species that exist together in both time and space is called:


66. Which is irrelevant for pea?


67. What is the most common outcome in the F2 generation of a cross between a tall plant and a dwarf plant?


68. Two phenotypically normal individuals have an affected child.What can we conclude about the parents?


69. The ratio for law of independent assortment is


70. Haemophillia C 


71. A gene with multiple phenotypic effect is called:


72. Secretors have dominant secretor gene “Se” on chromosome:


73. Mendel studied


74. The position of gene is


75. The antiserum contains


76. Which of the followings is true breeding variety?


77. The law of segregation gives genotypic ratio in F2 as


78. Which of the following statements is not true?


79. The 9 3 3 1 ratio is given by


80. Which of the following characters is not studies by Mendel?


81. Mendel’s law of which states that a random assortment of maternally and paternally derived chromosomes in meiosis results in gametes that have different combinations of these genes?


82. The genic system for determination of sex is present in:


83. If an individual has a recessive phenotype for a given trait, the genotype must be


84. A chestnut coloured horse crossed with a white coloured horse results in a palomino coat colour.This is an example of


85. What happens when both alleles of a gene pair independently express in a heterozygote?


86. A gamete without any sex-chromosome is called:


87. Match bean in beanbag with one of the followings


88. Which of the following phenotypic results are expected from a dihybrid cross?


89. Who for the first time found white eye mutation in Drosophila?


90. Can independent assortment be demonstrated in a monohybrid cross?


91. Blood group MN has antigen


92. If test cross gives all dominant characters it means the parent is


93. Mendel laid the foundation of


94. Phenotype is


95. The scientist who renamed factors as genes was


96. If genes are not linked, a genotype of PpRr can produce how many different kinds of gametes?


97. Which genotype is normally not found in a gamete?


98. A recessive gene can be expressed if the genotype is


99. Match particulate hereditary factor of Mendel with one of the followings


100. ABO blood groups were discovered by


101. Kathy’s brother has cystic fibrosis.Her husband has no family history of cf.What is the chance that Kathy’s child has inherited the cystic fibrosis?


102. The more phenotypic tissue than genotypic ratio is


103. Variations are produced due to


104. Blood group O can receives


105. Position of a gene on the chromosomes is called its:


106. If Mendel had chosen more than seven traits in his plants, he might have run into some confusing results regarding


107. Relatives who have children together have a much higher risk of having children affected by.


108. Which of these traits zigzags from maternal grandfather through a carrier daughter to a grandson?


109. The part of DNA which controls a specific character is


110. The organisms produced by self cross differing in one characters are


111. If test cross gives 50 percent dominant and 50 percent recessive characters it means the parent is


112. About 20 percent suffere from haemophilia B due to disturbance in factor 


113. Mendel’s laws are explained by


114. If an organism has TtRr genotype, then which of the following gametes does not follow law of independent assortment?


115. Which of the following traits is transmitted directly from an affected father to only his sons?


116. A sample population of 100 plants has number of alleles


117. A heterozygote offspring quantitatively exceeds the phenotypic expression of both the homozygote parents due to:


118. The blood group without antigen is


119. Partners of gene pair are


120. Drosophila males for eye color are:


121. Blood group A can be donated to


122. Which of the followings is homozygous?


123. The cross in which two characters are followed at the same time is called


124. When Mendel conducted his experiments, he needed to transfer pollen grains from a male reproductive organ to a female reproductive organ in a plant.What is this process called?


125. How many gene pairs contribute in wheat color?


126. Which of the following is an example of a dihybrid cross?


127. A co-dominance cross between a homozygous red and a homozygous white snapdragons produces


128. Mendel was the first biologist to


129. Consider the cross AaBbAaBb.If the alleles for both genes exhibit complete dominance, what genotypic ratio is expected in the resulting offspring?


130. Which geneticist has compiled a compendium of human genetic traits called mendelian inheritance in man?


Short Questions

1. Can child have more intelligence than his parens?
2. Compare monohybrids with dihybrids.
3. Define genetics?
4. Define law of segregation in genetics?
5. Define laws of Mendel. Define Mendel’s law of segregation . Define law of segregation.
6. Define Mendel’s Law independent Assortment or simultaneous ingeritance of two traits?
7. Define Mendel’s law of segregation?
8. Define pleiotropy?
9. Define population?
10. Differentiate between Allele and multiple allele?
11. Differentiate between Autosome and sex chromosome?
12. Differentiate between continuous and discontinuous variations?
13. Differentiate between dominance and epistasis. What is epistasis? How it differs from dominance?
14. Differentiate between Dominance and epistasis?
15. Differentiate between dominant and recessive alleles?
16. Differentiate between Dominant and recessive trait?
17. Differentiate between gene and genome.
18. Differentiate between homozygous and heterozygous terms in genetics?
19. Differentiate between IDDM and NIDDM.
20. Differentiate between incomplete dominace and codominance?
21. Differentiate between monohybrid and dihybrid individuals?
22. Differentiate between multifactorial and polygenic traits.
23. Differentiate between phenotype and genotype.
24. Differentiate between probability and product rule.
25. Differentiate between protanopia, deuteranopia and tritanopia.
26. Differentiate between qualitative and quantitative traits.
27. Differentiate between sex limited and sex influenced trait?
28. Differentiate between Wild type and mutant?
29. Differentiate between X-linked and Y-linked genes.
30. Differentiate between X-linked and Y-linked traits.
31. Differentiate between X-linked dominant and X-linked recessive traits.
32. Distinguish between polygenes and pleiotropy. Define pleiotropy. What is pleiotropy and its example?
33. Does the dominant allele modify the determinative nature of its recessive partner?What sort of relationship do they have?
34. Explain incomplete (partial) dominance?
35. Explain law of independent assortment?
36. Explain the term ‘locus’ in genetics?
37. Give the concept of fixed allele.
38. How and why did Mendelian factors behave like chromosomes?
39. How can ABO-incompatility protects the bady against a more severe Rh incompatibility?
40. How can linked genes be separated from each other?
41. How many alleles are responsible for four types of blood groups A, B, AB and O?
42. How many gene pairs are considered to control human skin colour which is a polygenic trait?
43. How sex determination occurs in yeast?
44. How sexual dimorphism is exhibited in Drosophila?
45. If the alleles do not assort independently which type of combination is missing in the progeny?
46. Name different types of dominance relations among alleles?
47. Name the organism that lack sex chromosomes?
48. The value of parental combination of two linked gene AB and ab is 40, 40 and of recombinant gene Ab and aB is 10, 10 respectively.Find recombination frequency.
49. Was pea a lucky choice for Mendel? What would have happened if he had studied an eighth character?
50. What are alleles (allelomorphs)?
51. What are Alleles?
52. What are compound sex chromosomes and their example?
53. What are genes and alleles?
54. What are multiple alleles?
55. What are polygenetic traits?
56. What are pseudoautosomal genes?
57. What are the genes and alleles?
58. What are X-linked and Y-linked genes? Give one example of both.
59. What do we mean by P₁ and F₁ generations in genetics?
60. What do you know about hypophosphatemic rickets?
61. What is a gene pool?
62. What is a gene?
63. What is a nullo gamete?
64. What is a test cross?Why did Mendel devise this cross?
65. What is a true-breeding variety of an organism with respect to a character?
66. What is a universal blood donor?
67. What is bean-bag genetics? What is a gene pool? Differentiate between gene and gene pool.
68. What is Bombay phenotype?
69. What is codominance?
70. What is Cross over or recombinant frequency?
71. What is crossing over? What is its importance?
72. What is epistasis?
73. What is gene pool?
74. What is Gregor Mendel famous for?
75. What is Linkage group?
76. What is Locus?
77. What is meant by linkage, linked genes and linkage groups?
78. What is meant by universal blood donor and universal recipient?
79. What is MODY?
80. What is multifactorial inheritace?
81. What is Over dominance?
82. What is punnett square?
83. What is test cross? Why did Mendel suggest this cross? Give the significance of test cross. What is test cross? Give its uses.
84. What is testicular feminization syndrome?
85. What is the difference between heterogametic and homogametic individuals? What is heterogametic individual? Give example.
86. What is the difference between phenotype and genotype?
87. What is the importance of test cross?
88. What is the product rule?
89. What name has now been given to the factors (elements) of inheritance, discovered by Mendel ad by whom?
90. What phenotypic and genotypic rations are obtained in the F₂ generation of a monohybrid cross?
91. What would happen if alleles of a pair do not segregate at meiosis?How would it affect the purity of gamete?
92. What would happen if dissimilar alleles of a pair do not segregate at meiosis? How would it affect the purity of gametes?
93. Which one is true colour blindness monochromacy or dichromacy?
94. Which type of traits can assort independently?
95. Which types of genes do not obey law of independent assortment?
96. Who discovered ABO-blood groups and when?
97. Who explained the genetic basis of ABO-blood group and when?
98. Why Bernstein is famous for?
99. Why does the blood group phenotype of a person remain constant through out life?
100. Why has each gamete equal chance of getting one or the other allele of a pair?
101. Why Mendel is famous for?

Long Questions

1. Define and explain multiple alleles. Describe multiple allelic blood group system of man. Discuss the genetics of ABO blood group system. Explain the ABO blood group system.
2. Define and explain sex-linkage in Drosophila.
3. Define and explain test cross.
4. Define Mendel’s law of Independent Assortment.Explain it with an example.
5. Describe law of segregation with an example.
6. Describe Mendel’s law of segregation.
7. Describe the genetics of colour-blindness in humans.
8. Describe the Mendel’s law of independent assortment with an example
9. Discuss sex-linkage in humans with one example.
10. Discuss the genetics of ABO blood group system.
11. Discuss the genetics of color-blindness. Describe the genetics of color-blindness in humans.
12. Explain codominance with the help of MN blood gorup system in man.
13. Explain different patterns of sex determination. Explain different patterns of sex determination in animals
14. Explain in detail diabetes mellitus and its types.
15. Explain Sex Determination in Plants.
16. Give genetics of colour-Blindness.
17. Give genetics of hemophilia.
18. How Morgan experimentally proved the theory of Heredity?
19. What are reasons to use Drosophila as an experimental organism?
20. What is epistasis? Explain it with an example of Bombay phenotype.
21. What is incomplete dominance? Explain it with an example.
22. Write a note on Bombay phenotype and pleiotropy.
23. Write a note on codominance with an example.

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