Bacteria: The Ancient and Essential Organisms

Bacteria, one of the oldest organisms, are crucial to life on Earth. They can cause diseases but also support health by living in the gut. Bacteria are unicellular prokaryotes, lacking a membrane-bound nucleus, with DNA in the nucleoid. They have a flexible cell wall, flagella for movement, and pili for attachment and DNA exchange. Bacteria have chromosomal and plasmid DNA, the latter providing antibiotic resistance and toxin production. They are found everywhere, in diverse shapes and sizes, and play vital roles in vitamin production, immune support, and more.

How old are bacteria estimated to be?

• 2.5 billion years

• 1.5 billion years

• 4.5 billion years

• 3.5 billion years

Which of the following diseases is NOT caused by bacteria?

• Tuberculosis

• Cholera

• Diabetes

• The Plague

What is the approximate ratio of bacterial cells to human cells in the body?

• 5:1

• 1:1

• 10:1

• 20:1

Which of the following is NOT a benefit provided by gut bacteria?

• Bone strengthening

• Tumor prevention

• Vitamin production

• Pathogen protection

Compared to plant and animal cells, bacterial cells are:

• The same size

• Variable in size

• Larger

• Smaller

Bacteria are classified as:

• Multicellular eukaryotes

• Unicellular eukaryotes

• Multicellular prokaryotes

• Unicellular prokaryotes

Where is the DNA located in bacterial cells?

• Chloroplast

• Mitochondria

• Cytoplasm

• Nucleus

What is the primary role of ribosomes in bacterial cells?

• DNA replication

• Protein synthesis

• Energy production

• Cell division

What is the function of pili in bacteria?

• Attachment and DNA exchange

• Movement

• Energy production

• Photosynthesis

Which type of DNA in bacteria carries extra information like antibiotic resistance?

• Mitochondrial DNA

• Plasmid DNA

• Chromosomal DNA

• Nuclear DNA