Question

question 1 (2.5 points)
how do ray - finned fish keep from sinking?
they are constantly swimming
their fins are constantly moving
they have lungs that are always filled with air
they have a swim bladder that is filled with gas
they have a skeleton that is less dense than the surrounding water
question 2 (2.5 points)
this arthropod is the vector for lyme disease.
spider
tick

Explanation:

• Question 1: Ray - finned fish have a swim bladder. The swim bladder is an internal organ filled with gas (usually oxygen, nitrogen, and carbon dioxide). By adjusting the amount of gas in the swim bladder, the fish can change its buoyancy. When the swim bladder is filled with more gas, the fish becomes less dense than the surrounding water and floats; when gas is removed (usually through a process involving the fish's blood vessels that can absorb or release gas), the fish becomes more dense and can sink or stay at a lower depth.
• Question 2: Lyme disease is caused by the bacterium Borrelia burgdorferi. Ticks (especially the black - legged tick, also known as the deer tick in North America) are the main vectors (organisms that transmit the pathogen). When a tick bites an infected animal (such as a mouse or deer), it can pick up the bacteria. Then, when the tick bites a human, it can transmit the bacteria, causing Lyme disease. Spiders are not known to be vectors for Lyme disease.

Answer:

• Question 1: they have a swim bladder that is filled with gas
• Question 2: tick