How Much Do You Know About…Genetics?

January 23, 2019

DNA_Overview21. Genes are made up of building blocks called

A. Amino acids.
B. Nucleotides.
C. Proteins.
D. Carbohydrates.

2. Other than the chimpanzee, what surprising species do we share the most genetic similarities?

A. Fruit fly.
B. E. Coli.
C. Mice.

3. Humans may not be programmed to live longer than 120 years. True or False?

4. How many genes are in the human genome?

A. Millions
B. Hundreds of thousands
C. About 20,000

5. Individual people will find that their genomes

A. Are Identical to other people’s genomes.
B. Differ by less than 1%.
C. Differ significantly, by more than 10%.
D. Are completely unique to them, unless they have an identical twin.


1. B. Nucleotides. A nucleotide is an organic molecule that is the building block of DNA and RNA. Nucleotides are carbon-based molecules rich in phosphorus and nitrogen and are the information molecules of all living creatures.

2. C. Mice. Humans share 98% of the same genetic material with chimpanzees,and we share over 80% with other mammals, like mice and pigs, which is why both are used as genetic model systems. This means that if something works in a pig or a mouse, it has a higher possibility of working in a human. Humans share more than 60% of their genes with fruit flies and banana plants too! We even share genes with bacteria like E. coli, although the percentage is much lower because the genome sizes are vastly different.

3. True. In theory, scientists think that humans have the genetic coding that prevents us from getting older than 120 years of age. This is due to a limited amount of time that cells can divide.

4. C. A surprising find of the human genome sequencing effort was that humans carry about 20,000 protein-coding genes, which is not much more than those carried by a fruit fly (about 15,000) and less than those carried by maize plants (about 32,000).

5. B. By most current estimates, humans vary by less than 0.1%. In other words, two people can share as much as 99.9% of the same genetic material. A mind blowing fact—the person sitting next to you could be made up almost the same genetics as you.