Principles of Inheritance and Variation MCQ for NEET Biology

Principles of inheritance and variation MCQ: The principles of inheritance and variation is a crucial subject that receives significant weight in competitive exams and is covered in the class 12 biology curriculum. The fundamental ideas of heredity and biological theories are explained in this chapter.

NEET Biology MCQ

Principles of Inheritance and Variation MCQ

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Principles of Inheritance and Variation MCQ with Solution

Principles of Inheritance and Variation MCQ

Q 1. Which of the following statements about aneuploidy is false?

1. Occurs because a homologous pair of chromosomes is not disjointed.
2. Occurs because non-homologous chromosomes are not conjoined.
3. One gamete acquires an additional chromosome.
4. A different gamete develops a chromosomal deficiency.

Answer- Option (2) is correct.

Explanation: Non-disjunction of non-homologous chromosomes prevents aneuploidy from developing. Instead, it results from the homologous pair of chromosomes' non-disjunction. It causes the development of a gamete with an additional chromosome and a gamete without one chromosome in the other.

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Q 2. Which of the following examples of aneuploidy is false?

1. Turner's syndrome,
2. Down syndrome,
3. Klinefelter's syndrome,
4. Phenylketonuria.

Answer- Option (4) is correct.

Explanation: Aneuploidy does not occur in phenylketonuria. Aneuploid disorders include Down's syndrome, Klinefelter's syndrome, and Turner's syndrome; Down's and Klinefelter's show trisomy problems, whilst Turner's syndrome displays monosomic abnormalities.

Q 3. Which of the following types of mutations occurs the most frequently?

1. Somatic mutation,
2. Germline mutation,
3. Forward mutation,
4. Backward mutation.

Answer- Option (3) is correct.

Explanation: The most frequent sort of mutation is a forward mutation, in which the normal or wild type of gene transforms into a new genotype that may be dominant or recessive. A forward mutation is a genetic change from a wild-type to a mutant allele or the generation of a new mutation from a wild-type allele. New qualities in the population evolve as a result of the forward mutation.

Q 4. Which of the following chemicals can cause mutations in both replicating and non-replicating DNA?

1. Acridines
2. Nitrous acid
3. Base analogs;
4. Mustard gas.

Answer- Option (2) is correct.

Explanation: The chemical mutagen nitrous acid is mutagenic to both replicating and non-replicating DNA. Strong mutagens known as acridines can cause frameshift or gibberish mutations. Numerous compounds are mutagenic or capable of resulting in mutations.

Q 5. Which of the following assertions about ionizing radiation is false?

1. They disrupt the chromosomes.
2. The ionized cells display aberrant cell division
3. Radiation dosages are directly inversely correlated with the frequency of caused mutations.
4. Cancer is not caused by it.

Answer- Option (4) is correct.

Explanation: Ionizing radiations, which induce chromosomal breakage, are to blame for several forms of cancer. The ionized cells exhibit aberrant cellular division. Additionally directly inversely correlated with radiation doses is the incidence of caused mutations. Ionizing radiation efficiently breaks up molecular interactions by dislodging electrons (ionization).

Q 6. Which of the following claims about polyploidy is false?

1. It is frequently observed in plants,
2. Causes sterility in animals,
3. Reduces the number of chromosomal sets,
4. Either increases or increases the number of chromosome sets.

Answer- Option (3) is correct.

Explanation: Polyploidy does not refer to chromosomal sets having less than two sets. After the telophase stage of cell division, cytokinesis does not take place in polyploidy settings, which causes a rise in the total number of chromosomes in an organism. Plants frequently exhibit polyploidy, which causes sterility in mammals.

Q 7. Which of the following techniques may be used to identify an inheritance pattern within a family?

1. Pedigree analysis
2. Chromosome analysis
3. Nuclear analysis
4. Cytoplasm analysis

Answer- Option (1) is correct.

Explanation: Pedigree analysis, a method of researching human genetic illnesses, may be used to track the pattern of inheritance of Mendelian disorders that are passed down to offspring in accordance with Mendelian principles.

Q 8. When is it possible for a woman to be colorblind?

1. The father has normal vision and the mother is a carrier;
2. The father has normal vision and the mother is colorblind;
3. The father is colorblind and the mother has a normal vision;
4. The father is colorblind and the mother is a carrier.

Answer- Option (4) is correct.

Explanation: A girl can only be colorblind under two circumstances: i. when her father is colorblind and her mother carries the disease; ii. when both her father and mother are colorblind.

Q 9. How many sickle cell genotypes are there in the population?

1. One
2. Two
3. Three
4. Four

Answer- Option (3) is correct.

Explanation: In a population, sickle cell anemia can occur in three different genotypes. These are

1. HbA HbA: Regular people
2. HbA HbS: Healthy people who transmit the illness by acting as carriers;
3. HbS HbS: People who have the disease but don't reach adulthood.

Q 10. Which of the following assertions about alpha-thalassemia is false?

1. Involves the HBA1 and HBA2 genes
2. Is inherited in a Mendelian dominant manner
3. Is associated with the deletion of the 16p chromosome
4. Leads to a reduction in the synthesis of  globin

Answer- Option (2) is correct.

Explanation: Alpha-thalassemia is not passed down in a Mendelian-dominant manner. Instead, it is passed down by a Mendelian recessive mechanism. It is linked to the deletion of the 16p chromosome and involves the genes HBA1 and HBA2.

Q 11. Which of the following is a cause of thalassemia?

1. RBC defects
2. WBC defects
3. Platelet defects
4. Lymphocyte defects

Answer- Option (1) is correct.

Explanation: A series of diseases collectively referred to as thalassemia are caused by a deficiency in the production of globin polypeptide in RBC. The excess of other globin chains that build up in our bodies and cause various illnesses result from the absence or diminished synthesis of one of the globin chains.

Q 12. Which of the following claims would be accurate if garden pea plants from Mendel's garden were sampled?

1. Round seeds were more prevalent than wrinkled seeds,
2. Wrinkled seeds were more prevalent than round seeds,
3. Both round and wrinkled seeds were equally prevalent,
4. The response depended on the time of day the sample was taken.

Answer- Option (1) is correct.

Explanation: Even when a recessive allele is present, the dominant allele can still express. Thus, dominant phenotypes are more prevalent. Because round seeds outnumber wrinkled seeds, they would be more common.

Q 13. Which of the following characteristics is not a result of Mendel's research?

1. Analyses based on mathematics
2. More extensive sampling
3. Creation of a trustworthy and relevant data source
4. Repeatedly destroying the model organism

Answer- Option (4) is correct.

Explanation: Mendel studied a huge sample of pea plants using the reliable scientific method as well as mathematical and statistical tools, making his findings unique in their field. He also established a trustworthy and respectable data source that may be used regularly to draw conclusions. Furthermore, his methods required taking care of the model organism at hand and were ethical even by today's standards.

Q 14. What process results in a genuine breeding line?

1. Self-pollination,
2. Cross-pollination,
3. Artificial pollination, and
4. Allogamy

Answer- Option (1) is correct.

Explanation: The line that is homozygous for an allele is considered to be a genuine breeding line. Repeated self-pollination over many generations can accomplish this. As a result, features that would normally be suppressed by the presence of dominant alleles are revealed that are encoded by recessive alleles.

Q 15. Which of the following is not a pair of opposing characteristics Mendel studied?

1. Axial and terminal flowers,
2. Full and constricted pods,
3. Green and yellow pods,
4. Pink and white flowers.

Answer- Option (4) is correct.

Explanation: Mendel examined seven pairs of opposing features during his investigations. These comprised terminal flowers, full and constricted pods, axial and yellow pods, as well as green and yellow pods. Violet and white were the two floral colors that were examined.

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