Question

1. a long chain of genes

chromosome
dna
allele
trait

Explanation:

To solve this, we analyze each term:

• A chromosome is a long chain of genes (along with associated proteins), as it consists of a DNA molecule with many genes arranged along it.
• DNA is the molecule that genes are made of, not a chain of genes.
• An allele is a variant form of a gene, not a chain of genes.
• A trait is a characteristic determined by genes, not a chain of genes.

So the correct option is the one labeled "chromosome".

Answer:

The correct option is the one with "chromosome" (the fourth option from the left, as per the image, with the blue - filled radio button).