binary fission and viral replication

3.2.2

which cells divide by binary fission?

prokaryotic cells, bacteria

what happens in binary fission?

DNA loop and plasmids replicate. DNA loops move to opposite poles of the cell. cell membrane pinches inwards, dividing the cytoplasm. a new cell wall forms between the DNA molecules

how many times does the circular DNA replicate?

once

how many times do the plasmids replicate?

more than once

what is the result of binary fission?

two daughter cells with one copy of circular DNA and a variable number of plasmid copies

why can’t viruses undergo cell division?

they are non-living and acellular

where do viruses reproduce and why?

inside host cells because they are parasitic

how do viral cells replicate?

attach to the host cell with their attachment proteins, inject their nucleic acids into the cell. host cell replicates the nucleic acids and assembles a new virus. the host cell bursts and releases the new virus particles

factors affecting growth rate of bacteria

temperature, O2 conc, glucose conc, nucleotide conc

why does increasing temperature increase rate of bacterial growth?

increases rate of enzyme action

why does increasing O2 concentration increase rate of bacterial growth?

increases rate of respiration

why does increasing glucose concentration increase rate of bacterial growth?

increases respiration

why does increasing nucleotide concentration increase rate of bacterial growth?

increases DNA synthesis