BBC Nature - Fish filmed spitting ostracod 'fireworks' 19 August 2014Last updated at 09:42 Ostracods illuminate when threatened to deter predators from eating them One of nature's most dazzling underwater displays, bioluminescence, has been captured as a form of self-defence by a BBC film crew. Ostracods are one of the ocean-living animals which give off light when they are disturbed. They produce the chemicals luciferin and luciferase, which emit light when mixed together.
The process is called bioluminescence, an adaptation that allows animals to be seen in the complete darkness of the deep sea. To demonstrate why organisms are able to generate light, ostracods were put into a tank containing cardinal fish, which eat plankton. When an ostracod is swallowed, it emits a burst of light, making the cardinal fish spit it out. Physicist and BBC presenter Helen Czerski said: "It's like a little fish firework.
" Biggest eye "Their dazzling glare acts like a security light," Dr Czerski added. In the deep ocean it is the only light there is. Artificial Leaves Might Help Power the World. Geology.com: News and Information for Geology & Earth Science.
Chapter 10 - Dihybrid Crosses. DIHYBRID CROSSES A dihybrid cross involves two alleles per trait for two traits, for a total of four alleles. Gamete formation must occur for guinea pigs and other sexually reproducing organisms to reproduce. Thus, the first step to solving a dihybrid cross is to see how the various alleles (forms of the two traits) combine in the gametes.
The principle of independent assortment explains this combining of alleles. Independent assortment means that each allele of a particular trait has an equal chance of being in a gamete with each of the alleles of the other trait; that is, B has an equal chance of ending up with S or s during gamete formation. For example, the male guinea pig's alleles for this dihybrid cross are BbSs. In this example, the same possible allele combinations apply to the female, and to both guinea pigs' gametes. F1 guinea pigs are crossed (mated). Next, all possible gamete combinations (with their alleles) from the two F1 guinea pigs must be considered. Chapter 3: The slight negative charge at one end ...