There are mainly three principles of heredity, the principle of segregation, the principle of dominance, the principle of independent assortment. Heredity is defined when characters are transferred from one generation to the next.
Question 1: What is the reason for down syndrome in humans?
Answer: Because of the extra copy of chromosome number 21
Explanation: Down syndrome is caused by aneuploidy in humans because of the trisomy at chromosome number 21. In this disease, there is an asymmetrical skull, mental retardation, and decreased muscle tone.
Question 2: Which organism is used as a model organism in genetic studies?
Answer: Drosophila melanogaster.
Explanation: This organism is used in the laboratory because it has a short life cycle and clear differentiation of sexes and produces a large number of offspring in a single reproduction.
Question 3: The human skin color is an example of which type of inheritance?
Answer: Polygenic inheritance.
Explanation: Polygenic inheritance means which is controlled by more than two genes in cumulative form. In the case of human skin color, the three genes A, B, C control the clour of human skin in additive form.
Question 4: What is the reason for sickle cell anemia disease?
Answer: Missense mutation.
Explanation: The sickle cell anemia disease is caused by the change of amino acid from glutamic acid to valine because of the change of one base pair in the codon, in this, the shape of RBC is sickle-shaped which is insufficient to carry oxygen in the blood.
Question 5: What is the phenotypic and genotypic ratio in incomplete dominance?
Explanation: The incomplete dominance is the limitation of mendelian inheritance where two alleles express incompletely and produce a new phenotype, it is also called partial dominance.
Question 6: The scientist who discovered the concept of linkage in drosophila.
Answer: T.H Morgan.
Explanation: Morgan discovered linkage first time in drosophila, linkage is the phenomenon in which two genes are linked together and pass on to the next generation in linked form.
Question 7: Hemophilia-B is the disease caused by the deficiency of which clotting factor?
Answer: Deficiency of factor (ix)
Explanation: Hemophilia is a disease in which the blood loses the ability to clot because of the lack of clotting factors and there is a lot of blood loss during any injury.
Question 8: Who has given the law of dominance?
Answer: Gregor Johann Mendel discovered the law of dominance.
Explanation: Law of dominance means the one allele is dominant over the other allele and the allele control the characters of the individuals.
Question 9: Color blindness in humans shows which kind of linkage?
Answer: It is an x-linked disorder.
Explanation: Color blindness is the x-linked disorder which is when there are two copies of x-chromosomes that carry the disease. It found more in males as compared to females because males carry only one copy of the x-chromosome and females have two copies.
Question 10: Which syndrome is caused by the presence of an additional copy of the x-chromosome?
Answer: Kleinfelter’s syndrome.
Explanation: In this type of disorder, the x-character increases so it affects males, the males develop more feminine characters, such as the development of breasts and poor muscle growth.