Biology Ch 8 Class 12 Variation and Genetics





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Read the passage below to answer the question:

Hemophilia is a disorder in which blood fails to clot. Saad, a male hemophiliac, marries Sara, a normal woman and together they have four children, two boys (Ahmed and Ali) and two girls (Alia and Ayesha). None of the children display the symptoms of Hemophilia. Ahmed, Ali, Ayesha, and Ali all marry normal individuals and have children. None of Ahmeds or Ali’s children, male or female, display symptoms of hemophilia, but the sons of Alia and Ayesha display symptoms of hemophilia while the daughters of Alia and Ayesha do not.

If one of Ali’s daughters marries a normal man,what is the probability that one of their children will display symptoms of hemophilia:

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A child with AB blood group who was born to a mother of the genotype IAIA cannot have the father of the genotype:

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In which of the following cases, genotypic and phenotypic ratio will remain same in F2 generation

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In birds the male is the homogametic sex. A male bird showing the recessive trait was mated with a female showing the dominant trait of a characteristic governed by a pair of alleles which are sex-linked. What is the probability that the male offspring will show the dominant trait?

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Mendel concluded that each organism has two hereditary factors for each trait, now called:

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Which statement about dominant and recessive alleles is not correct?

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Haemophilia occurs because of:

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Which of the following X – linked recessive trait that is more common in human males than in human females?

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To check the homozygosity or heterozygosity of apparently dominant trait, we do the test cross by crossing it with:

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If we cross round (RR) seeded plants with wrinkled (rr) seed plant, and get F1 round seeded. In F2 generation, what will be genotypic ration of plants try Punnett square method?

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A cross between F1 hybrids and either of parents is called:

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The position of a gene on chromosome is called

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The trait “Kernel colour in corn” in controlled by how many pairs of genes

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Filial is a Latin word. It means

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Ahmed’s blood CANNOT clot properly; he was diagnosed with hemophilia A. He passed this trait to his grandson through his:

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Which of the following condition is hybrid A. TT B. Tt C. tt D. All of these

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______ alleles both have an effect on the phenotype of a heterozygous organism:

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Erythroblastosis foetalis occurs when:

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D) Both mother and baby are Rh-positive

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Phenotype for both TT and Tt is tall, so the allele T is known as:

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In the pea plants, the factors round and yellow seeds (RRYY) is dominant over wrinkled and green seeds (rryy). Keeping this in mind, identify the seed that has the genotype round and green.

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J. Seiler in 1914 discovered which type of sex determination in moths?

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When phenotype of a heterozygote is in between the phenotypes of both the homozygous parents, it is called:

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A man with blood group “A” marries a woman of blood group “B”. Both are heterozygous. What is the off-springs having phenotype “O”

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Read the passage below to answer the question:

Hemophilia is a disorder in which blood fails to clot. Saad, a male hemophiliac, marries Sara, a normal woman and together they have four children, two boys (Ahmed and Ali) and two girls (Alia and Ayesha). None of the children display the symptoms of Hemophilia. Ahmed, Ali, Ayesha, and Ali all marry normal individuals and have children. None of Ahmeds or Ali’s children, male or female, display symptoms of hemophilia, but the sons of Alia and Ayesha display symptoms of hemophilia while the daughters of Alia and Ayesha do not.

Which of the following individuals are heterozygous for hemophilia:

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How many genes control Rh blood group system?

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In nature, Garden pea is

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Which traits are most likely to affect men than women?

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How many pairs of homologous chromosomes are present in Pisum sativum

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Red green colour blindness is a sex linked recessive trait. If a colour blind man marries a woman with normal vision whose father is colourblind and they have a daughter, what is the probability that she will be colourblind?

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In cats, the genes controlling coat-color are co-dominant (incompletely dominant) and are carried on the X chromosomes. When a black female was mated with a ginger male the resulting litter consisted of black male and tortoise-shell female kittens. What phenotypic ratio would be expected in the F2 generation?

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Linked genes with closer loci ______ Mendel’s law of independent assortment as they _____ assort independently.

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If the seed is heterozygous yellow (Yy). In a test cross, what will be the probability of appearance of seed colors?

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Which of the following does not belong to the same linkage group?

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The gene which controls ABO group has how many alleles in an individual

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Baldness is most frequent in

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Genotype of blood group ‘AB’ in human is ______.

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The law of dominance is illustrated in the garden pea by:

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A pure breeding tall pea plant was crossed to dwarf plant what will be the frequency of dwarf plants in F1

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An X to A ratio of ⅖ in drosophila produces:

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A continuously varying trait is encoded by alleles of two or more different genes located at different loci, all influencing the same trait in an additive way is known as ________.

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Continuous variations in a population were first observed by:

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Which of the following is monohybrid cross

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The genes which do not follow law of independent assortment

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What is the risk of color blind baby boy in a family when mother is color blind but father is normal?

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Two animals are mated. One is homozygous dominant for one character and homozygous recessive for another. The other animal Is heterozygous for both characters. How many phenotypes are expected in the offspring of this cross?

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A pure breeding plant with the dominant phenotype of character P and the recessive phenotype of character Q was crossed with another pure breeding plant with the recessive phenotype of chracter P and the dominant phenotype of Q. The offspring of this cross were crossed with a double homozygous recessive for P and Q and the following results were obtained:

22 were phenotypically dominant for P and recessive for Q
5 were phenotypically dominant for both P and Q
4 were phenotypically recessive for both P and Q
24 were phenotypically recessive for P and dominant for Q
Which one of the following types of Inheritance is illustrated by these results?

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______ are more common in human males than females.

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The total number of genes present in a particular population, at a particular time is called:

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In ‘Complete Dominance’:

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Read the passage below to answer the question:

Haemophilia is a disorder in which blood fails to clot. Saad, a male haemophiliac, marries Sara, a normal woman and together they have four children, two boys (Ahmed and Ali) and two girls (Alia and Ayesha). None of the children display the symptoms of Haemophilia.

Ahmed, Ali, Ayesha, and Ali all marry normal individuals and have children. None of Ahmed’s or Ali’s children, male or female, display symptoms of haemophilia, but the sons of Alia and Ayesha display symptoms of haemophilia while the daughters of Alia and Ayesha do not.

Which of the following best explains the reason that Ahmed, Ali, Ayesha and Alia do not display symptoms of haemophilia, even though their father, Saad, is a haemophiliac.

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If a heterozygous individual shows the complete effect of both alleles, the type of inheritance would be

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When both the alleles of a gene pair are same, the organism is said to be:

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An Rh negative woman is married to an Rh positive man whose father was also Rh negative. What are the chances that their child will be affected?

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What CANNOT be true for a man having B+ve blood group?

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Hybrid black Guinea pigs are crossed with each other. The resulting offsprings will be:

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A trait whose alleles are present in both males and females but prominent more in one sex than other is a:

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The disease, which is caused by defect in a single gene or pair of genes is referred to as:

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The type of gene interaction in which the effect caused by a gene at one locus interfere with the effect caused by another gene at another locus is known as:

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If we cross round yellow seeded plant with green wrinkled seeded plants, what will be phenotypic ratio at F2 generation?

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A pea plant has purple colored flowers (dominant trait). To check the genotype, which of the following cross is performed

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Pick the correct option about Drosophila.

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A monohybrid cross yielded 3:1 in F2. What could be mode of inheritance?

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In question number 2 what will be frequency of dwarf plant in F2

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Which of the following characters of pea plant is dominant?

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A pure breeding tall plant was crossed to dwarf plant. What would be probability of “Tt” genotype in F2

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A pea plant with yellow seed was crossed to a plant having green seeds. What will happen in F1; if plants are true breeding

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