click below
click below
Normal Size Small Size show me how
AgEny2l 4
the chromosomal basis of DNA
| Question | Answer |
|---|---|
| Thomas Hunt Morgan | genes are found on chromosomes |
| Drosophila are used because | there are lots of offspring, they have four pairs of chromosomes |
| genetic linkage | genes on the same chromosome can be linked if they are close together |
| X linked genes | do not independently assort but instead form recombinants |
| during prophase 1 of meiosis | chiasmata form which lead to recombinants |
| linkage is said to be incomplete if | new combinations occur in the offspring |
| to make a genetic map of a chromosome | recombinant frequencies are used |
| a 1% recombination is called | a centimorgan |
| the smaller the recombination percentage | the closer the genes |
| the retina contains | cone cells which absorb coloured light |
| the gene for cones which absorb blue light | are on autosmomes |
| the gene for cones which absorb red light(protan) and green light(deutan) | is on the x chromosome |
| there are two types of haemophilia | Haemophilia A and B |
| in haemophilia A | factor 8 is missing |
| in haemophilia B | Factor 10 is missing...Christmas disease |
| egg cells are also called | homogametes |
| sperm cells are also called | heterogametes |
| males have more sex linked disorders | due to the length of the Y chromosome there is less likelyhood of crossing over |
| Fragile x syndrome | caused by repeating base triplets cgg on an x chromosome |