Questions for ‘Genes: How few are needed for life?’

An artists’ depiction of DNA. The different colors correspond to the building blocks that make up long segments that make up an organism's genes. Together, genes provide the blueprint for the actions of cells — and, ultimately, an entire organism.

Equinox Graphics / Science Source

To accompany feature “Genes: How few are needed for life?”


Before Reading

1.    What are genes and how do they relate to DNA?

2.    Where are genes found?

During Reading

1.    What is a genome?

2.    Describe where genes are found?

3.    How many genes do many bacteria, such as E. coli, contain?

4.    Most of syn3.0’s genes carry out what four essential jobs?

a.    _________________________________________

b.    _________________________________________

c.    _________________________________________

d.    _________________________________________

5.    How many genes in syn3.0 have genes of unknown function?

6.    Describe what it is that synthetic biologists do.

7.    Explain how the minimal-gene version of syn3.0 by Venter’s group was created and how that differs from previous efforts by others to find a minimum genome.

After Reading

1.    Why do scientists work to build synthetic organisms, such as the one described in this story? What questions can these organisms answer that natural ones cannot?

2.    The genes of organisms large and small change, naturally, all of the time through mutations and other forms of adaptation. Here, scientists physically created unnatural changes. What special concerns might arise if organisms with synthetic genomes got loose into the environment? Do you think they would be more — or less — likely to spread and share their genes with others? Explain your reasoning.


1.    The syn3.0 microbe was developed from a bacterium that originally had 901 genes. On a percentage basis, how many genes did it lose? What share (percent) of syn3.0’s genes are now involved in metabolism? In gene copying and DNA repair? Show your work.