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Bacteria
How do bacteria reproduce?
Binary Fission
A form of asexual reproduction
The daughter cells are identical to the parent cell.
Genetic material is copied and split into two different cells.
How big are bacteria?
About 1 μm in diameter. (1 micrometer)
Putting it in perspective- Your hair is 100 μm in diameter A grain of salt is 1,000μm wide
Why is a small size necessary?
Small size is extremely important because it allows for a large surface area-to volume ratio.
A small volume but large surface area allows for the bacteria to get rid of waste and absorb nutrients faster.
+What protects bacteria from the outside world?
Cell Wall
Just like plants, bacteria have a cell wall to protect them from the elements.
Some bacteria have a capsule or slime layer for extra protection.
Endospore- many bacteria have a spore within the cell wall that they can reduce to in tough environments
How do bacteria move?
Flagella!
Move like the motor of a boat.
• Some bacteria have pilli, which are projections that help bacteria to hold onto surfaces.
What is unique about bacterial DNA?
It’s circular!
A bacteria’s entire genome is on one circle of DNA
Bacteria also have plasmids which can pass between bacteria. This allows for a drug-resistant bacteria to pass it on to other bacteria.
Does bacteria have a nuclear membrane?NO! Prokaryotes don’t have a true
nucleus.
Bacterial DNA is usually localized in the nucleoid.
Why is bacteria important to farmers?
Bacteria can change ammonia (from fertilizer) into nitrate (used by plants.)
Some bacteria like Rhizobium live on the roots of legumes (like soy beans) and are able to put nitrogen back into the soil.
+Whiteboards
You have seen many pictures of bacteria throughout the power point. On your own, try to draw a bacteria cell on your whiteboard and label the important parts.
+Did it look like this?
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