1.Many freshwater invertebrates eliminate ammonia by:

A. Converting it to uric acid and eliminating it with solid wastes.
B. simple diffusion across the gill membranes.
C. converting it to urea and eliminating it in their urine.
D. simple diffusion across the skin.******

2. Which of the following excretory processes do saltwater and freshwater fishes share?
A. The both conserve water by producing small amounts of concentrated urine.
B. They both actively pump salt across their gills. ********
C. The both avoid drinking water.
D. They both produce lots of watery urine.

3. What excretory characteristic does a garden spider share with a sparrow?
A. They both convert nitrogenous waste to uric acid. *********
B. They both produce lots of diluted urine.
C. They both excrete very concentrated salt solutions.
D. They both produce very dry feces.

My choices are marked with *******
Please help - Thank you

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You're welcome.

To answer these questions, we can break down the options and eliminate the incorrect ones based on our understanding of excretory processes in freshwater invertebrates, saltwater and freshwater fishes, and garden spiders.

1. Many freshwater invertebrates eliminate ammonia by:
A. Converting it to uric acid and eliminating it with solid wastes. - This is not a common excretory process in freshwater invertebrates.
B. Simple diffusion across the gill membranes. - While diffusion can play a role in excretion, it is not the main process for eliminating ammonia.
C. Converting it to urea and eliminating it in their urine. - This is a possible excretory process for some organisms, but not a common method in freshwater invertebrates.
D. Simple diffusion across the skin. - Freshwater invertebrates commonly eliminate ammonia through simple diffusion across their skin, making this the correct answer.

2. Which of the following excretory processes do saltwater and freshwater fishes share?
A. They both conserve water by producing small amounts of concentrated urine. - This is not a characteristic shared by both saltwater and freshwater fishes in terms of excretion.
B. They both actively pump salt across their gills. - Both saltwater and freshwater fishes actively pump salt across their gills for osmoregulation, making this the correct answer.
C. They both avoid drinking water. - This is not a universal characteristic shared by all saltwater and freshwater fishes.
D. They both produce lots of watery urine. - This is not a characteristic shared by all saltwater and freshwater fishes.

3. What excretory characteristic does a garden spider share with a sparrow?
A. They both convert nitrogenous waste to uric acid. - This is the correct answer. Both garden spiders and sparrows excrete nitrogenous waste in the form of uric acid, which helps conserve water.
B. They both produce lots of diluted urine. - This is not a characteristic shared by garden spiders and sparrows.
C. They both excrete very concentrated salt solutions. - This is not a characteristic shared by garden spiders and sparrows.
D. They both produce very dry feces. - This is not a characteristic shared by garden spiders and sparrows.

So the correct answers are:
1. D. Simple diffusion across the skin.
2. B. They both actively pump salt across their gills.
3. A. They both convert nitrogenous waste to uric acid.