Genes Lecture 1 Flashcards
rise of complex life
merging of energy producing alpha photobacterium and information containing Archaea
what was the original cell
Loki
discovered in hydrothermal vents in Norway
Asgard-Cell Archaea
telomeres
chromatin structure that prevents DNA damage/ degradation during replication
features of telomeres
contain loop structures to stop recombining DNA and forming/ fusing with other chromosomes
which cells contain telomerase and why
embryonic stem cells, cancer cells and germ cells to prevent chromosomes from getting shorter
how many genomes do eukaryotes have
2: nuclear and mitochondrial
features of mitochondrial genomes
DNA not bound to histones
small and circular histones
maternal inheritance
similar to a bacterial cell which supports the endosymbiotic model of eukaryotic evolution
intergenic sequences
DNA sequences between genes
intragenic sequences
DNA sequences within genes e.g. introns
what type of inheritance does mitosis give rise to
somatic
mitosis
both daughter cells inherit one copy of the duplicated genome
special case of mitosis
some cytoplasmic material can be asymmetrically distributed leading to reprogramming of daughter cells
what inheritance does meiosis give rise to
germ line
meiosis
haploid genome: one copy of the genome and enables sexual reproduction
symmetrical division of mitosis
daughter cell
asymmetrical division of mitosis
produces differentiated daughter cells and stem daughter cells
why is mitosis asymmetrical division beneficial
prevents premature exhaustion of adult stem cells such as muscle gut and blood cells
karyotypes
allows observation of a full set of human chromosomes
difference between male and female meiosis
have different timings
males produce haploids directly whereas females have an extra step: in meiosis 1: formation of a polar body and in meiosis 2: ejection of a polar body
