Glowing Jellies PDF

Glowing Jellies Imagine splashing in a calm ocean cove at night. Scientists think that jellies glow as a defense...

Glowing Jellies Imagine splashing in a calm ocean cove at night. Scientists think that jellies glow as a defense As you splash, you notice green flashes in the against predators. The bright glow might startle water: glowing jellies! These are called crystal or confuse predators, or it might attract bigger jellies. They can’t sting humans, so you can predators that could scare away or eat the swim and watch them glow green as you bump jelly’s attacker! Glowing is an adaptive trait for into them. jellies because it helps them survive in their environment. Glowing Jellies © 2018 The Regents of the University of California. All rights reserved. Permission granted to purchaser to photocopy for classroom use. Image Credit: Shutterstock. Where does this trait of being able to glow come from? In 1992, some scientists decided to find out. They examined the cells of crystal jellies and discovered that the glow comes from a protein. They gave the protein the name Green Fluorescent Protein, or GFP for short. To find out how these jellies make GFP, scientists investigated the jellies’ genes. A gene is instructions for an organism’s cells to make a particular protein. Scientists were able to find the gene that gave the jellies’ cells instructions to make the GFP protein. If a jelly has the GFP gene, its cells can make green fluorescent protein. If its cells make green fluorescent protein, the jelly can glow. The gene leads to the protein, which leads to the trait. A protein molecule called Green Fluorescent Protein (GFP) causes some jellies to glow in the dark! How does a jelly get the gene for glowing? When a pair of adult jellies reproduce, each one passes down genes to the offspring. Genes are found on chromosomes and chromosomes come in pairs. An organism has two copies of Gene A Gene C any given gene because there is one copy on Gene B each chromosome in a pair. However, the two Chromosome copies of any particular gene can be the same version or different versions. These different versions of a gene are called alleles. When jellies reproduce sexually, each parent passes down This diagram shows three pairs of chromosomes. one of each of their chromosomes (with all their Chromosomes have many genes, but in this genes on it) to the offspring. If at least one of diagram only shows one for each chromosome. the adult jellies has the version of the gene that There are two copies of each gene, one on each is instructions for GFP, then that gene could be chromosome of the pair. When an organism passed down to the offspring. Offspring with reproduces sexually, it gives the offspring one of that gene will have cells that produce GFP, so each of its chromosomes and therefore one copy they will glow, also. of each gene. Glowing Jellies 1