Thylacosmilus is a marsupial, and Smilodon is a mammal. Thylacosmilus and Smilodon both have saber teeth, but they do not share an ancestor that had saber teeth. What are saber teeth for these organisms?1. anlogous structures2. homologous structures3. vestigial structures4. mutated structures

1. Analogous structures.

Explanation:

Analogous structures are defined as similar structures which evolved independently to perform same kind of work in two different organisms. In short we can say that analogous structures are not derived from same ancestor both the individuals having these structures developed them independently.

Convergent evolution best defines concept of analogous structures.

Another classical example of analogous structures is wings in birds and insects. Wings look similar and perform same function in both the organisms but their origin is not same i.e. birds and insects do not share common ancestor which had wings leading to the conclusion that they both developed wings independently.

"a scientist studying a whale and its surroundings would need to understand the structure of atoms in case something was negatively affecting the whale or its surroundings."

explanation:

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1. loamy sand is about 80% sand with 10% clay and defined mostly by sand particles with some clay to provide structure and fertility. the sand particles are easily visible and the soil holds structure but breaks apart easily.

2. scott sand can improve his soil quality by incorporating more silt and organic matter into the soil. peat moss and organic matter can also be incorporated.