Unit 6: Genetics — Online MCQ Test
ZOOLOGY · CLASS 12 INTERMEDIATE 2 YEAR · Telangana State Board
Practice Unit 6: Genetics with a free chapter-wise online MCQ test.
This chapter covers: This chapter details Mendelian genetics human chromosomal inheritance sex-linked inheritance gene interaction linkage crossing over chromosomal abnormalities and human genetic diso....
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Unit 6: Genetics — Important Questions & Answers
Who proposed the basic principles of heredity known as Mendel's laws?
- A. Gregor Johann Mendel
- B. Thomas Hunt Morgan
- C. Charles Darwin
- D. Robert Hooke
Answer: A. Gregor Johann Mendel
Gregor Mendel is known as the Father of Genetics. He formulated the laws of inheritance based on experiments on pea plants.
Gregor Mendel is known as the Father of Genetics. He formulated the laws of inheritance based on experiments on pea plants.
In humans, the sex of the baby is determined by which chromosome contributed by the father?
- A. X chromosome only
- B. Y chromosome only
- C. Autosome 21
- D. Mitochondrial DNA
Answer: B. Y chromosome only
The father contributes either X or Y chromosome. If the sperm carries Y, the offspring becomes male; if it carries X, the offspring becomes female.
The father contributes either X or Y chromosome. If the sperm carries Y, the offspring becomes male; if it carries X, the offspring becomes female.
Mendel's law of segregation states that:
- A. Two genes for a trait are always inherited together
- B. Alleles separate during gamete formation
- C. All traits are controlled by multiple genes
- D. Dominant alleles always disappear in the next generation
Answer: B. Alleles separate during gamete formation
According to the law of segregation, the two alleles of a gene separate during gamete formation, so each gamete gets only one allele.
According to the law of segregation, the two alleles of a gene separate during gamete formation, so each gamete gets only one allele.
Which of the following is NOT a chromosomal disorder?
- A. Turner syndrome
- B. Klinefelter syndrome
- C. Phenylketonuria
- D. Down syndrome
Answer: C. Phenylketonuria
Phenylketonuria is a metabolic disorder caused by a gene mutation, not a chromosomal abnormality.
Phenylketonuria is a metabolic disorder caused by a gene mutation, not a chromosomal abnormality.
Which of the following is the correct match of disorder and chromosomal constitution?
- A. Turner syndrome - 47, XXY
- B. Klinefelter syndrome - 45, XO
- C. Down syndrome - 47, XX or XY, +21
- D. Patau syndrome - monosomy X
Answer: C. Down syndrome - 47, XX or XY, +21
Down syndrome is trisomy 21, represented as 47, XX +21 or 47, XY +21. The other options are mismatched.
Down syndrome is trisomy 21, represented as 47, XX +21 or 47, XY +21. The other options are mismatched.