What are the functions and adaptations of gill filaments, and what are the modes of animal reproduction and fertilization advantages/disadvantages?

Here are the answers to the questions you sent:

Question 1:

a) Name the organelle.
The diagram shows a gill filament. (Note: The term "organelle" is typically used for structures within a cell; this diagram depicts a macroscopic organ structure).

b) State the function of the part named in (a) above.
The function of a gill filament is gaseous exchange, which involves the absorption of oxygen from water and the release of carbon dioxide.

c) How is part (a) adapted to its function?

• It has a large surface area due to numerous lamellae, maximizing the area for gas diffusion.
• It has thin walls (often one-cell thick) to provide a short diffusion distance for gases.
• It has a rich blood supply to maintain a steep concentration gradient for efficient gas exchange.

Question 2:

a) Name two main groups of animals based on their mode of reproduction.

• Oviparous (animals that lay eggs)
• Viviparous (animals that give birth to live young)

b) State two advantages of internal fertilization over external fertilization.

• There is a higher chance of successful fertilization because the gametes are protected within the female reproductive tract.
• The zygote or embryo is protected from predation and harsh environmental conditions.

c) State two disadvantages of the process in (b).

• It requires copulation (mating), which can be complex and energy-intensive.
• It typically results in fewer offspring compared to external fertilization.

Question 3:
The diagram for the investigation setup is not visible in the image, so this question cannot be answered.