Answer:
The correct answer is option a. "scales".
Explanation:
The missing information of this question is the following:
"Terry catches a ray-finned fish from the ocean and notices that attached to its flank is an equally long, snakelike organism. The attached organism has no external segmentation, no scales, a round mouth surrounded by a s*cker, and two small eyes. Terry concludes it is a hagfish."
Gymnophiona is a group of amphibians characterized by having dermal scales as integumentary element. These amphibians are tetrapods and their scales are comprised of several layers of unmineralized collagenous fibers. The skeleton of the hagfish is made entirely of cartilage, therefore it is very likely that the tooth-like objects of hagfish's are made of cartilage, just like the scales of the tetrapod.
A radioactive element is an element which is subject to spontaneous degeneration of its nucleus followed by the emission of alpha, beta and gamma particles. All elements with atomic numbers greater than 83 are radioactive.
The given phrases that describe radioactive elements are-
They have a consistent number of particles
- the particles are alpha, beta and gamma particles.
They have a half-life that determines their rate of decay.
Explanation for other options:
Not all elements occur in nature. Radioactive decay rates may not be constant as the decay happens when a radioactive substance emits a particle. It is not possible to predict exactly when a given atom of a substance will emit a particular particle. When the radioactive element release energy and particles, it decays.
Its called bioamplification
I believe it is oxygen and carbon dioxide
