Prokaryotes can exchange genes directly between cells in a process known as horizontal gene
transfer (HGT).
In some cases this can occur between different species of bacteria and is one way of
spreading antibiotic resistance.
xlvi.
Pilli are needed to exchange genes because the bacterial cell wall prevents two bacterial cells from
fusing their membranes and exchanging genes.
xlvii.
conjugation- physical connection (conjugation tube) is made between two cells.
The DNA on a
plasmid is duplicated and the copied DNA is transferred.
xlviii.
transformation- direct uptake, incorporation and expression of exogenes DNA from its surroundings
through membrane
xlix.
transduction- injection of foreign DNA by a bacteriophage virus into a host bacterium
b.
Protists
i.
Protists- all eukaryotes that are not plants, fungi, or animals
ii.
a major subdivision within the Bacteria (PVC superphylum & Candidate Phyla Radiation) as well as an
origin of the Eukaryotes from within the Archaea
iii.
the sister group to the Eukaryotes is a clade within the Archaea made up of the Thorarchaeota and
Lokiarchaeota.
iv.
Loki, reveals that it is the most “eukaryote-like” prokaryote so far discovered. The study suggests that
the ancestor of eukaryotes might have had an actin cytoskeleton and rudimentary internal structures
composed of membranes.
v.
Malaria is caused by an alga.
1.
Malaria is caused by the apicomplexan protist Plasmodium.
There are four species of
Plasmodium known to infect humans, P. falciparum being the most deadly.
2.
“apicoplast” is a remnant chloroplast found in a group of parasitic protists known as
apicomplexans.
The most famous members of this group are Plasmodium (causative agent
of malaria) and Toxoplasma ((causative agent of toxoplasmosis).
The apicoplast has retained
its own genome, which is now reduced to only 35kb in size and no longer contains genes for
photosynthesis but none the less is still clearly derived from a chloroplast ancestor
3.
The synthetic equivalent of Quinine is known as chloroquine.
For decades chloroquine was
the preferred treatment for malaria.
4.
Since the early 1930’s the worldwide incidence of malaria had been declining but is now
increasing= Plasmodium has evolved resistance to chloroquine
