Principles of Inheritance and Variation - Chapter End Test | Class-12 Biology

CLASS-XII    BIOLOGY     CHAPTER END TEST

CHAPTER-04: PRINCIPLES OF INHERITANCE AND VARIATION

1. Z Z / ZW type of sex determination is seen in:  (1M)

1. Penguin

2. Crow 

3. Grasshopper

4. Mosquito 

2. If a genetic disease is transferred from a phenotypically normal but carrier female to only some of the male progeny, the disease is: (1M)

1. Autosomal dominant

2. Autosomal recessive

3. Sex-linked dominant

4. Sex-linked recessive

3. In sickle cell anaemia glutamic acid is replaced by valine. Which one of the following triplets codes for valine? (1M)

1. G G G

2. A A G

3. G A A

4. G U G

4. Occasionally, a single gene may express more than one effect. The phenomenon is called: (1M)

1. multiple allelism

2. mosaicism

3. pleiotropy

4. polygeny

5. Study the figures given below and answer the question.   

Identify in which of the crosses the strength of linkage between the genes is higher. Give reasons in support of your answer. (2M)

6. What is test cross? Mention its importance? (2M)

7. Identify ‘a’, ‘b’, ‘c’, ‘d’, ‘e’ and ‘f’ in the table given below:   (3M)

8. A chromosomal abnormality, chromosomal anomaly, chromosomal aberration, chromosomal mutation, or chromosomal disorder, is a missing, extra, or irregular portion of chromosomal DNA. Some common examples are Down syndrome, Klinefelter syndrome and Turner syndrome. There is no cure for a chromosomal disorder. Once a child is born, they will require therapy from a multi-disciplinary team to learn to manage their symptoms. Genetic therapies are approaches that treat genetic disorders by providing new DNA to certain cells or correcting the DNA. (4M)

1. What is the main reason behind abnormal chromosome numbers in the foetus?

2. Karyotype 45 A + XY (i.e., 47 chromosomes) is characterized by which chromosomal disorder?

3. Overall masculine development with feminine features e.g., Development of breast (Gynecomastia) is related to which disorder?

4. Write karyotype of Turner’s syndrome

9. Answer the following : (5M)

1. Haemophilia is a sex-linked recessive disease. Study the pedigree analysis given below showing the inheritance of the disease in a family and answer the questions that follow:  

1. Give the evidence from the above analysis, which suggests that the disease is (1) sex-linked and (2) caused by a recessive allele.

2. Write the possible genotypes of the individuals '2' and '5'.

2. Why is thalassemia categorised as a Mendelian disorder? State the condition when an individual will suffer from the disease.