Question 1: Define natural selection and explain its role in evolution.

Answer: Natural selection is the process where organisms with advantageous traits are more likely to survive and reproduce, leading to the gradual change of traits in a population over time.

Question 2: List three main factors that can lead to variation within a species.

Answer: Genetic mutations, sexual reproduction, and environmental influences.

Question 3: In your own words, describe how a favourable trait becomes more common in a population over generations.

Answer: A favourable trait increases an organism’s chances of survival and successful reproduction. These individuals pass the trait to their offspring, leading to a higher frequency of the trait in the population over time through natural selection.

Question 1: In a population of 500 beetles, 150 have a gene for a specific shell colour. After several generations, 300 beetles show this shell colour. Calculate the change in frequency of this gene in the population. Use the formula: Frequency = (Number of individuals with trait) / (Total population).

Answer: Initial frequency = 150/500 = 0.3; Final frequency = 300/500 = 0.6; Change in frequency = 0.6 - 0.3 = 0.3.

Question 1: Describe a basic experimental setup to investigate how environmental changes can influence natural selection in a local bird population. Include variables and safety precautions (theory only).

Answer: An experiment could involve observing bird populations in different environments, such as areas with different food sources or predator presence. Variables include environmental conditions (independent) and bird traits like beak size or foraging behaviour (dependent). Safety precautions involve ensuring minimal disturbance to wildlife, maintaining safe distances, and avoiding habitat destruction.

Question 2: Explain how selective breeding in agriculture is an application of natural selection principles.

Answer: Selective breeding involves choosing organisms with desirable traits to reproduce, increasing the frequency of these traits in subsequent generations, similar to natural selection but guided by humans.

Question 1: A study records the survival rates of moths with light and dark wings over a decade in an area with industrial pollution. Out of 1000 moths with light wings, 600 survive each year. Out of 1000 dark-winged moths, 800 survive each year. Interpret these data in terms of natural selection.

Answer: The data suggest that dark-winged moths have a higher survival rate, likely because they are better camouflaged against pollution-related environmental changes, leading to increased natural selection favouring dark wings.

Question 1: Discuss how understanding natural selection can help in managing antibiotic resistance in bacteria.

Answer: Understanding natural selection helps in managing antibiotic resistance by guiding appropriate antibiotic use, reducing selective pressure for resistant bacteria, and developing strategies to prevent the spread of resistance.

Question 2: Identify one ethical consideration scientists must take into account when conducting experiments related to evolution and natural selection.

Answer: Scientists must consider the welfare of living organisms and ensure that experiments do not cause unnecessary harm or environmental damage.