Answer Happy

12. Choose the right answer from the
following.
A species of fish lives in a part of the Southern Ocean that from time-to-time experiences cooling events that push the water temperature below zero degrees C. Because of the salt content of the water, it does not entirely freeze, but pockets of ice do form in some places. If a fish comes into contact with that ice, the ice crystals spread, freezing and killing the fish. The population size of this fish species begins to decline from these occasional ice-culling events. As the population size declines, becomes less effective in the population, while becomes a more prominent force. Oselection, drift Omigration, inbreeding Odrift, selection Ogene duplication, subfunctionalization is/are too weak to remove them. During this time period, begin to proliferate in the genome, because Otransposable elements, drift Omethylation sites, gene duplications Ointrons, drift Ointrons, selection Otransposable elements, selection A transposable element is transcribed from the one fish's genome and inserts itself into another chromosome upstream of a repeating DNA motif. The result of this event is the TE's transcription start site is combined with the repeating DNA motif to make a new gene, de novo. The effect of the resulting protein is to bind ice crystals and stop their spread within the fish - preventing it from freezing. This protection from freezing results in strong selection. Omethylation Opositive Ostabilizing Osexual Over more time, additional repeats around this new antifreeze gene facilitate slippage during DNA replication resulting in tandemly- duplicated genes proliferating over many generations. These genes are immediately preserved, creating a segmental duplication. What process was at work? OThe whole genome duplication creates a barrier to gene flow and the individuals with duplicates cannot mate with individuals without duplicates OThe immediate increase in transcripts for that gene are selectively beneficial Drift cannot see the new gene because it is shadowed OThe duplicate fine-tunes gene expression in different developmental stages