This diagram is called a pedigree chart or genetic lineage.

Here are the answers to your questions:

1.5.1

This diagram is called a pedigree chart or genetic lineage.

1.5.2

There are 3 sets of parents represented in this diagram.

• Individuals 1 and 2 are parents to 5, 6, 7, 8.
• Individuals 3 and 4 are parents to 9, 10, 11, 12.
• Individuals 8 and 9 are parents to 13, 14, 15, 16.

1.5.3

• a) To determine dominance, observe that individuals 1 and 2 both have black fur but produce offspring 8 with white fur. This means that black fur must be the dominant trait, and white fur is recessive. The dominant phenotype is black fur.
• b) Individual 9 is a filled square, which, according to the key, represents a male with black fur. The phenotype of individual 9 is black fur.

1.5.4

Using A for the dominant allele (black fur) and a for the recessive allele (white fur):

• a) Individual 8 has white fur. Since white fur is recessive, individual 8 must be homozygous recessive. Its genotype is $\boxed{\text{aa}}$.
• b) Individual 16 has black fur. Its parents are individual 8 (genotype aa) and individual 9. Individual 9 has black fur, but its parent 3 has white fur (genotype aa), meaning individual 9 must have inherited an 'a' allele from parent 3. Therefore, individual 9's genotype is Aa. When parents 8 (aa) and 9 (Aa) breed, the possible offspring genotypes are Aa and aa. Since individual 16 has black fur, its genotype must be $\boxed{\text{Aa}}$.