In which part of the respiratory system does gaseous exchange takes place? A Larynx B Pharynx C Trachea D Alveoli

Here are the answers to your questions:

1.1.1
Gaseous exchange in the respiratory system occurs in the alveoli.
The correct option is D.
Answer: D

1.1.2
The net increase of a population is determined by adding factors that increase population (births and immigrations) and subtracting factors that decrease population (deaths and emigrations).
The correct option is C.
Answer: C

1.1.3
Factors that cause a decrease in population size are emigration (individuals leaving) and predation (individuals being killed by predators). Immigration and natality (birth rate) cause an increase.
The correct option is C.
Answer: C