Science Teks

4A

• Why are bacteria so different from normal cells?
• Compare and contrast prokaryotes and eukaryote
• What are bacilli, cocci, and spirilla and their advantages?

4A-1

4A-2

4A-3

4B

• How do viruses invade/destroy cells?
• Is there one way bacteria can reproduce or are there various ways ?

4B-1

In binary fission (a kind of asexual reproduction), a bacterium's DNA replicates and the one-celled organism splits into two separate, independent bacteria.

In conjugation (which is similar to, but technically not, sexual reproduction) two individual bacteria get together and one sends out a bridge of cytoplasm to the other. This "male" bacterium then transfers some of its DNA to the "female" bacterium.

In transformation, bacteria pick up bits of genetic material (called plasmids) from their environments, often by engulfing another bacterium or smaller organism.

In transduction, viruses pick up bits of DNA from one bacterium, which they then insert into the next individual they infect.

4C

• What is penicillin. What is its effect on viruses?
• What do viruses feed off of?
• Can antibiotics be used on viruses? Why or Why not?

4C-1
Penicillin is an antibiotic used to kill bacterial infections like ear infections. It comes from penicillium fungi and there are many types of it: Penicillin V, Penicillin G, Penicillin VK are the main types. Unfortunately, it does not kill viruses as penicillin halts all cell wall synthesis, and this is mainly during fission. Viruses cannot reproduce without a host, so penicillin does not affect viruses.

4C-2
The condition that distinguishes animals and plants from inorganic matter, including the capacity for growth, reproduction, functional activity, and continual change preceding death. Viruses do not really "eat" because they are not alive.They carry pieces of DNA or RNA and attach to and enter a living host's cells (plant or animal) and cause those cells to create more viruses. The virus causes this replication by modifying the DNA of the "invaded" host cells to make them stop their original function and modify it to reproduce the viruses DNA. For example the flu just enters the body and attacks .

11B

• How can beneficial bacteria affect the environment?
• What would a cell do if endospores weren't present?
• What is the role of endospores and how do they help bacteriums survive?

11B-1

11B-2

11B-3