Which of the following statements about genomes is not correct?
Humans have around 20 000 genes
Species vary in the number of genes they have
The number of genes of an organism is not proportional to genome size
Humans have the most genes of any organism
Which of the following statements, correctly describes the impact of the substitution mutation shown below?
The codon encoding an amino acid was changed to a stop codon, truncating the polypeptide
The sequence of amino acids may code for a different protein structure
The resulting polypeptide chain will be elongated
There will be no change in the polypeptide chain
Which row correctly describes the features of prokaryotic chromosomal DNA?
| A. | Associated with histone proteins | Circular |
| B. | Not associated with histone proteins | Linear |
| C. | Not associated with histone proteins | Circular |
| D. | Contains a few hundred genes | Circular |
Which of the individuals below is represented by the following karyogram?
A male with a chromosomal abnormality
A genetically normal female
A male with Down syndrome
A female with Down syndrome
