Sickle cell anaemia has not been eliminated from the African population because :
- it is controlled by recessive genes
- it is not a fatal disease
- it provides immunity against malaria
- it is controlled by dominant genes
The Correct Option is C
Solution and Explanation
Sickle cell anemia has not been eliminated from the African population because it provides immunity against malaria. Heterozygous carriers of the sickle cell gene have some resistance to malaria, which is common in certain regions of Africa where the disease is prevalent.
Therefore, the correct option is (C): it provides immunity against malaria
Top Questions on Principles of Inheritance and Variation
- The inheritance of the AB blood group in humans is an example of -
- CUET (UG) - 2025
- Agriculture
- Principles of Inheritance and Variation
1. Perform a cross between two sickle cell carriers. What ratio is obtained between carrier, disease free and diseased individuals in F1 progeny? Name the nitrogenous base substituted, in the haemoglobin molecule in this disease.
2. Explain the difference in inheritance pattern of flower colour in garden pea plant and snap-dragon plant with the help of monohybrid crosses.
OR,
Explain with the help of well-labelled diagrams how lac operon operates in E. coli :
1. In presence of an inducer.
2. In absence of an inducer.- CBSE CLASS XII - 2025
- Biology
- Principles of Inheritance and Variation
Study the pedigree chart given below, showing the inheritance pattern of blood group in a family:
Answer the following questions:
(a) Give the possible genotypes of individual 1 and 2.
(b) Which antigen or antigens will be present on the plasma membranes of the R.B.Cs of individuals ‘5’ and ‘8’?- CBSE CLASS XII - 2025
- Biology
- Principles of Inheritance and Variation
The sequence of nitrogenous bases in a segment of a coding strand of DNA is
5' – AATGCTAGGCAC – 3'. Choose the option that shows the correct sequence of nitrogenous bases in the mRNA transcribed by the DNA.- CBSE CLASS XII - 2025
- Biology
- Principles of Inheritance and Variation
- A man whose father was colour-blind marries a woman who had a colour-blind mother and normal father. What percentage of male children of this couple will be colour-blind?
- CBSE CLASS XII - 2025
- Biology
- Principles of Inheritance and Variation
Questions Asked in NEET exam
A constant voltage of 50 V is maintained between the points A and B of the circuit shown in the figure. The current through the branch CD of the circuit is :
- NEET (UG) - 2025
- Current electricity
The output (Y) of the given logic implementation is similar to the output of an/a …………. gate.
- NEET (UG) - 2025
- Logic gates
- A parallel plate capacitor made of circular plates is being charged such that the surface charge density on its plates is increasing at a constant rate with time. The magnetic field arising due to displacement current is:
- NEET (UG) - 2025
- Displacement Current
What is Microalbuminuria ?
- NEET (UG) - 2025
- Human physiology
In the above represented plasmid an alien piece of DNA is inserted at the EcoRI site. Which of the following strategies will be chosen to select the recombinant colonies?
- NEET (UG) - 2025
- Genetic Engineering and Biotechnology
Concepts Used:
Human Endocrine System
The human endocrine system is a messenger system that balances or controls distant target organs through feedback loops of hormones released by the internal glands of an organism right into the circulatory system. The hypothalamus is the neural control node for all endocrine systems, in invertebrates.
Functions of the Human Endocrine System are:
The endocrine system controls a variety of body functions through hormone release. Hormones are built by the endocrine system's glands and pass throughout the bloodstream to various organs and tissues in the body. Hormones then command these organs and tissues about how to act.
The Endocrine System is in charge of the following bodily functions:
- Metabolic rate
- Development and growth of a human being
- Reproduction and sexual function
- Heart Rate
- Blood pressure
- The appetite is the need to eat
- Controls cycles of sleep and wakefulness
- Controls the temperature of the body