Muscles and internal organs
Answer:
The sum of an organism's observable characteristics is their phenotype. A key difference between phenotype and genotype is that, whilst genotype is inherited from an organism's parents, the phenotype is not. Whilst a phenotype is influenced the genotype, genotype does not equal phenotype
Answer: The lock-and-key mechanism is usually associated with the complementary shapes of an enzyme with a single substrate wherein the lock that is being referred to is the enzyme and the substrate is the key. One right sized substrate (key) fits into the active site (key hole) of the enzyme (lock).