Independent and Dependent Variables

One chicken is injected with a growth hormone while another chicken is not injected with a growth hormone. After one year, both chickens are weighed. What is the independent variable?

What is the dependent variable when one chicken is injected with a growth hormone and another is not, and both are weighed after one year?

A bug repellent was sprayed on one arm. On the other arm, the bug repellent was not sprayed. After 2 hours, the number of bug bites are recorded. What is the independent variable?

A bug repellent was sprayed on one arm. On the other arm, the bug repellent was not sprayed. After 2 hours, the number of bug bites are recorded. What is the dependent variable?

What is the independent variable in the scenario where Javier and his twin sister have the same science exam, but Javier sleeps for 9 hours and his sister sleeps for 6 hours before the exam?

Javier and his twin sister both have the same science exam. Javier sleeps for 9 hours the night before the exam and his sister sleeps for 6 hours. After they take the test, they both compare their test grades. What is the dependent variable?

What is the independent variable in the scenario where Group A exercises for a month and Group B does not?

Group A decides to exercise for a month. Group B decides not to exercise during the same month. Afterwards, they measure the amount of weight that each group lost. What is the dependent variable?

What is the independent variable when comparing test scores of a class that studies and a class that does not?

What is the dependent variable when comparing test scores of a class that studies and a class that does not?