Notatki Danniego part 4 Flashcards
Inversion -
A section of chromosome that has been rotated and replaced in position
- > a loop must be made
- > a chromosome with an inversion will be inherited as a block known as a supergene
translocation
Two nonhomologus chromosomes exchange parts
- > part of the Y chromosome can attack on to the x chromosome
- > gives XXy (x with a bit of y)
- > this makes you a male but you cannot produce sperm
position effect variegation
drosophila white eye gene carried on chromosome
- > gives red or white
- > cam give white eyes with red patterns
- > bit of the X chro0mosome has been translocated to another chromosome
- > shows the way genes are turned on/off sped up/slowed down by other genes
- > gene interaction
cancer
- usually loss of tumor suppressor which codes for the gap in cell division so cell reproduce too quickly
- can also have tumor accelerators
aneuploidy
- > incorrect number of chromosomes
- > malfunction in the formation of gametes can occur where both copies of the chromosome end up in one cell
95% of cases ?! (5% due to translocation)
- > Down’s syndrome an extra chromosome 21 (shortest chromosome)
- > flat face
- > enlarged colon
- > simple singerprints
- > single palmer crease
- >mental retardation - > a piece of 14 shifted on 21
Klinefelter syndrome
XXY - xx egg fertilised by a Y sperm
-> tall stature - slightly feminised physique - osteoporosis
-> female pubic hair, breast development - impaired IQ
1/500 males have Klinefelter
Turner syndrome
XO missing a chromosome
- > short - sterile - skin folds - brawn spots
- > heart issues - characteristic face
gynandromorph
male and female
- > can be split down the middle
- > can have two complete sets of genitalia
- > or a mish mash that is nothing like genitalia at all - > can interact with genes that are associated with sex chromosomes
- > eye colour on X chromosome for drosophila
HAPLODIPLOIDY IN BEES (18 STRONA OD NIEBIESKIEGO)
K
Autopolyploidy
spontenous naturally occuring genome doubling
diploid autotetraploid species
AA ———————————————————> AA AA
endoreduplication
Alloploidy
2 species hybridize and double chromosomes
AA \ allotetraploid
diploid = ————————————————->AABB
BB / Hybridization + endoreduplication
In wheat AA hybridized with BB. Then again with DD to give AABBDD hexaploid production wheat
- > Also AABB crossed with Rye (RR) to give tritical
- > An alloploid of emmer wheat and rye
- > productive in cold climates
Triploidy can create sterile organisms
- > seedless watermelons
- > oysters that can’t self-fertilize
Primate chromosomes
- chromosome bands almost identical to Gorrilas, chimps and orangutans
- > humans have slightly less
- > human also have a fusion of chromosome 2 which other primates do not.
- > near identical DNA sequences but split over 2 chromosomes
Asexual species tend to live in environmentally predictable places
- > can rely on inversions of chromosomes
- > don’t need to change genome to adept
More sexual species live in … as they need to ….
environmentally harsh places
change and adapt quicker
