Answer:
Analogous structures
Explanation:
These structures are similar but not derived from the common ancestor like homologous structures. Analogous structures are formed as a result of convergent evolution-type of evolution in which organisms develop on similar way but independently. An example of analogous structures are wings. Birds, insects and bats all have wings, with the same purpose (flight) but they evolved in their own way.
Answer:
The missing word is things.
However, the real question is how one material can serve so many purposes? That is what makes it possible for the spiders web to have a high "utility" value?
The answer is in how the spiders make the silk.
Explanation:
So it interesting to note that spiders do not make only one kind of silk. They vary depending on what purpose it's doing serve.
The most common type is Dragline Silk.
Dragline Silk: This contains spidroins. Spidroins fall under a category of a protein called scleroproteins. Because of its composition, a strand or fiber of Dragline has the same tensile strength as steel albeit more flexible. That is if one produced steel the diameter of a spider's silk, and compared both for strength, the silk will be stronger.
The spider produces Dragline silk in its silk glands where they are as viscous as a paste. From here is pulled out or extruded into lines of silk.
Other types of spider silk are:
- Capture-spiral silk. Also known as the Flagelliform, they are used for securing lines of the web. They are adhesive, very elastic, and possess high tensile strength.
- Tubiliform silk: They are also called Cylindriform. Its main use is for the protection of spider eggs. It is used to make a sac for which protects eggs. This type of silk is the toughest.
- Aciniform silk: For preserving fresh prey.
- Minor-ampullate silk: This type is used by spiders for creating temporary support while they are spinning a web. Etc.
Cheers
Answer:
macroevolution
Explanation:
Macroevolution occurs due to the genetic differences accumulates in the population of the same species which gets reproductively isolated from the older population and got different environments and resources to live.
Macroevolution leads to the creation of a new species over a long period of time because of the genetic difference that occurs due to mutation in the gene in the population who got reproductively isolated. So the new species evolved from the macroevolution.
