Genetics And Evolution

Eagles have binocular vision, which means that both eyes are positioned in such a way that they focus on the same object simultaneously. This gives them a field of view where both eyes overlap, allowing them to perceive depth and distance accurately. The main advantage of binocular vision for eagles is that it provides stereoscopic vision, meaning they can judge distances accurately, which is crucial for hunting and diving. Eagles need to be able to judge the exact distance to their prey from a great height and at high speeds. This depth perception allows eagles to strike their prey with precision. They can swoop down from a great height and grab their prey in mid-air or on the ground with remarkable accuracy, ensuring a successful hunt. Binocular vision also helps eagles focus on prey over long distances, providing them with clear and sharp images of objects far away, which is vital when hunting from the sky.

The theory of Natural Selection was proposed by Charles Darwin. He is known for his contributions to the theory of evolution, where he explained how species evolve over time due to the process of natural selection. Natural Selection is the process by which organisms better adapted to their environment tend to survive and produce more offspring, leading to the gradual evolution of species.

The organism used as an example to explain Industrial Melanism is the Peppered Moth (Biston betularia). Industrial Melanism refers to the darker coloration of organisms, which is often a result of environmental changes, such as pollution. The Peppered Moth evolved darker coloration during the Industrial Revolution, when soot from factories darkened the environment, making the lighter-colored moths more visible to predators.

N/A

The process by which new species arise from the existing ones is called speciation. Speciation is a key concept in evolutionary biology, as it explains the formation of new and distinct species from a common ancestor. Speciation can occur through various mechanisms such as: - Allopatric speciation, where geographic isolation leads to the formation of new species.
- Sympatric speciation, where new species arise from a single population without geographic isolation, often due to ecological or behavioral differences.
- Parapatric speciation, which occurs when populations are adjacent to each other but occupy different habitats or environments.
As these populations become isolated, genetic divergence occurs over time, and the differences accumulate, leading to the emergence of distinct species. This divergence can result from natural selection, genetic drift, or mutations.

Colour blindness is a sex-linked recessive trait carried on the X chromosome. In this case, the mother is a carrier of colour blindness (XC X), meaning one of her X chromosomes carries the colour blindness gene, while the other carries the normal vision gene. The father has normal vision (XY), meaning his X chromosome carries the normal vision gene and his Y chromosome determines male sex. The mother can pass on either her XC chromosome (carrying the colour blindness gene) or her normal X chromosome (X). The father will pass on either his X chromosome or his Y chromosome. The possible combinations for their sons (who must inherit the Y chromosome from their father) are: - XC (from mother) and Y (from father) → Colour blind son. - X (from mother) and Y (from father) → Normal vision son. Since the mother has a 50% chance of passing on the XC chromosome and a 50% chance of passing on the normal X chromosome, the probability of their son inheriting colour blindness is 50%. Final Answer: 50%.

In DNA, the nitrogenous bases follow a specific base-pairing rule: Adenine (A) pairs with Thymine (T), and Guanine (G) pairs with Cytosine (C). This means the amount of Adenine is equal to the amount of Thymine, and the amount of Guanine is equal to the amount of Cytosine. We are given that the DNA sequence has 300 nitrogenous base pairs, and 75 of them are Guanine. Since Guanine pairs with Cytosine, the number of Cytosine will also be 75. Therefore, the total number of Guanine and Cytosine combined is: 75 + 75 = 150 base pairs. The total number of base pairs is 300. After accounting for the 150 base pairs of Guanine and Cytosine, the remaining base pairs are: 300 - 150 = 150 base pairs. Since Adenine pairs with Thymine in a 1:1 ratio, the number of Thymine will be half of the remaining base pairs: (150)/(2) = 75 Thymine base pairs. The number of Thymine in this DNA sequence is 100, so the correct answer is (B). Final Answer: 100.

Genetic disorders are caused by abnormalities in the genes or chromosomes. Let's analyze the examples: - Colour blindness is a genetic disorder linked to the X chromosome.
- Albinism is a genetic disorder affecting the production of melanin in the body.
- Haemophilia is another genetic disorder, also linked to the X chromosome, affecting blood clotting.
- Malaria and Cholera are not genetic disorders; they are infectious diseases caused by pathogens, not genetic mutations.
- P. Colour blindness and Malaria: Incorrect. Malaria is not a genetic disorder.
- Q. Albinism and Cholera: Incorrect. Cholera is not a genetic disorder.
- R. Haemophilia and Colour blindness: Correct. Both haemophilia and colour blindness are genetic disorders.
- S. Haemophilia and Albinism: Correct. Both haemophilia and albinism are genetic disorders.
The correct answer is (B) because both R and S quoted genetic disorders correctly. Final Answer: R and S.