Final answer:
Mammals do not synthesize folate, while bacteria can.
Step-by-step explanation:
Mammals do not synthesize the vitamin folate but bacteria cannot. Folate, also known as vitamin B9, is important for various biological processes including cell division and DNA synthesis.
In mammals, folate must be obtained through the diet, while bacteria have the ability to synthesize it themselves. This is because bacteria have the necessary biochemical pathways to produce folate from the raw materials they require.
So, while mammals rely on obtaining folate from their diet, bacteria can make their own folate.