The arms of humans and the flippers of dolphins have a similar bone structure. so, they’re organs. the legs of a kangaroo and the legs of a jumping spider allow both organisms to jump. however, spiders are invertebrates, and kangaroos are vertebrates. this difference makes their legs structures.
1)a. analogous b. homologous c. vestigial
2)a. analogous b. homologous c. vestigial

i believe the correct answers are:

1) B. homologous

2) A. analogous

1)  B. homologous

2) A. analogous

Explanation:

The arms of humans and the flippers of dolphins are homologous organs as both are made of the same pentadactyle pattern of bone structure, but their function is different. Arms of humans perform the function of holding things and the flippers of dolphins are used for swimming. The legs of a kangaroo and the legs of a jumping spider are analogous organs because both organs are dissimilar in origin but perform the same function. They use for jumping.

from my research i have to the conclusion that decomposers, such as fungi, bacteria and invertebrates, play a critical role in nutrient cycling and without them the earth's ecosystem may not support life as we know it. elements such as carbon, nitrogen and phosphorus exist in limited amounts on earth, although huge amounts of carbon are being released into the atmosphere from underground sources now by humans. it is still extremely important that other nutrients be retained by the process of re-use. decomposers are organisms that are able to chemically break down dead material and make these elements available for use by other organisms. without this breakdown of dead material, dead bodies would pile up. so decomposers also play a role in clean up also. without them, life might not continue as we know it and dead material would overwhelm the earth.