Biodiversity Flashcards
1
Q
What happens in the lytic cycle?
A
- In the lytic cycle the virus will replicate itself
- The lytic cycle occurs in viral diseases such as smallpox, mumps or influenza
- Symptoms will occur shortly after exposure to the virus b/c the viral nucleic acid takes over the host cell’s DNA
- The host cell will then make copies of the viral nucleic acid & new viruses will be created
- The host cell will then burst open releasing those new viruses
2
Q
What happens in the lysogenic cycle?
A
- Happens in viruses such as AIDS - the virus “lurks”
- The virus will enter the host cell
- The virus will combine its DNA w/ the host’s DNA
- The DNA of the host cell & virus will be copied
- The virus can stay in a dormant state until it is releases (due to stress for example)
3
Q
Bacteria
A
- Single celled
- Prokaryotes - their DNA isn’t surrounded by a membrane
- Cell organelles aren’t surrounded by a membrane
- Their DNA is made of a single chromosome
- They reproduce asexually by binary fission
4
Q
Who demonstrated that many diseases of plants & animals were caused by bacteria? (in the mid 1800s)
A
Louis Pasteur
5
Q
Who discovered a new pathogen called a “virus” in 1898?
A
Martinus Beijerinck
6
Q
What is a virus?
A
- They are so simple they lack most components of a cell
- They can’t eat or reproduce unless they are inside of a cell
- Most biologist don’t consider them living organisms - just mobile genes that live off of cells
7
Q
What traits do viruses have w/ living things?
A
- They have genetic material that’s capable of mutation or genetic recombination
- They can adapt to changing environments through replication & mutation w/ in their host cells
8
Q
What traits do viruses have w/ non living things?
A
- They have no cell organelles & aren’t able to reproduce their own cellular energy or proteins (they rely on their host cell for all cellular functions)
- Can only replicate in w/in living cells
- They don’t grow
- Can be crystallised which is common for non-living things
