1. Metamerism is a phenomenon that appears in some animals and it refers to linear disposition of their body segments that are similar in structures. These body segments are called metamers or somites and they include only the ectoderm and mesoderm (not endoderm). Metamers repeat serial and they have role in advanced locomotion. Metamerism might be homonymous when its strict or heteronymous when units are grouped together to perform similar functions.
2. Earthworm is an example of homonymous metamerism, meaning that its segments are strict. The subtype of homonymous metamerism in which Earthworm belongs is called true metamerism because in each its segment there is a repetition of organs and muscles. On the other hand, Arthropods are example of heteronymous metamerism when units are grouped together to perform similar functions. So, they have for example, head (5 metameres), thorax (3 metameres), and abdomen (11 metameres).
3. Similarities between Earthworm and Arthropods’ metamerism are:
• Metamers are similar in structure
• Each metamer has its function
• Involved in locomotion
Differences is that metamers in Earthworm all work together for the whole organism while in Arthropods they are functionally separated in groups with different functions.
Answer:
It should be D
Explanation:
I hope this helps! Let me know if I am wrong.
Answer:
C. Species today descended with modifications from ancestral species.
Explanation:
This answer that "Species today descended with modifications from ancestral species" presents image of evolution in totality, and not the procedures or steps of natural selection.
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Here, is the complete question.
In his book On the Origin of the Species, Charles Darwin described how species change over time. Which of the following is NOT part of his observations that describes the mechanisms of natural selection?
A. Organisms produce more offspring than can survive.
B. Disease and natural disaster will limit population growth.
C. Species today descended with modifications from ancestral species.
D. Organisms with advantages will survive and reproduce.
The role that they play is they break down dead plants and animals and waste(poop). This allows for plants to get nutrients in the means of fertilizer from what the decomposes break down. It also prevents from dead plants and animals piling up.