Characteristics of Lancelets:
Small
Elongated
Marine invertebrate
Lacks a jaw
No sense organs
Has a notochord
Example: Lamprey
Characteristics of Tunicates:
Marine invertebrate
Has an outer coat that is rubbery or hard
Has two siphons
Examples: sea squirts, salps
I hope this is the answer that you were looking for.
Answer:
Silent mutations are mutations in DNA that do not have an observable effect on the organism's phenotype. They are a specific type of neutral mutation. The phrase silent mutation is often used interchangeably with the phrase synonymous mutation; however, synonymous mutations are not always silent, nor vice versa.
My answer: Because the actual thing you might be modelling might be too small or large to replicate, (for example you cannot draw a plant cell TO SCALE because it’s way too small to see with a bare eye).
And if the item is too big, you won’t be able to fit it in a small space; if you were to draw it or create it in 3D.
I hope this helps!
Sorry if the response is too short, try rewording if you need to :)