Question 1: Explain the difference between genetic sex determination and environmental sex determination.

Answer: Genetic sex determination involves chromosomes determining sex, while environmental sex determination depends on external factors like temperature.

Question 2: Describe how the presence of the Y chromosome influences male development in humans.

Answer: The Y chromosome carries the SRY gene, which triggers testes development and leads to male characteristics.

Question 1: In humans, which chromosome combination results in a female? Provide the specific sex chromosome notation.

Answer: XX

Question 2: Name an organism that uses environmental factors, such as temperature, to determine sex.

Answer: Some reptiles, like certain turtles and crocodiles.

Question 1: In a sample of 200 human births, 102 are male and 98 are female. Calculate the sex ratio (number of males per 100 females). Show your working.

Answer: Sex ratio = (Number of males / Number of females) × 100 = (102 / 98) × 100 ≈ 104.08 males per 100 females.

Question 2: A study reports that in a particular species, 60% of offspring are females. If 150 offspring are examined, how many are expected to be male? Show your calculations.

Answer: Number of males = 40% of 150 = 0.40 × 150 = 60 offspring.

Question 1: Describe a basic experimental setup to investigate the effect of temperature on sex determination in reptiles. Include variables and safety precautions.

Answer: An experiment could involve incubating eggs of the same species at different controlled temperatures. The independent variable is temperature, the dependent variable is the sex of hatchlings, and control variables include egg size and incubation conditions. Safety precautions include handling eggs carefully to prevent damage and ensuring proper temperature regulation to avoid harm to the eggs.

Question 1: How can understanding sex determination mechanisms be useful in the poultry industry?

Answer: It allows producers to select for desired sexes, such as producing only female hens for egg production, improving efficiency and profitability.

Question 2: Discuss a technological advancement that utilises genetic understanding of sex determination for controlling the sex ratio in a population.

Answer: Genetic engineering techniques, such as CRISPR, can be used to modify sex chromosomes or genes involved in sex determination, enabling control over the sex ratio in livestock or pest populations for agricultural or disease control purposes.