Question

Assume that you discovered Caenorhabditis elegans that crawl significantly slower than others. How would you determine whether this behavior was due to an injury from the environment or to an inherited trait? A goal of using animal models is to explain the molecular detail of specific behaviors encoded in the human brain. How would you compare the developmental biology experiments on memory and learning using the fruit fly, Drosophila melanogaster, as evidence about the evolution of a human behavior?

Answer 1

Answer:

1 Inherited traits are controlled by genes and can transferred or parsed to their pro geny. So inherited traits causing genes will be present in DNA of germ cell. So by analyzing the DNA of c. elegans results in the determination of inherited traits. Inherited traits will be present in the species ancestors. So if same phenotypic characters (slower Crawling) is present in these ancestors, then it is inherited. Environmental injury on behaviour will be a result by aquired traits. This cannot be transferred or passed to progenies. So if the progenies not showing the specific behaviour (slow crawling) then the trait is due to environmental injury. So analyzing DNA of the progeny and parents will show if it is inherited or Aquired trait. Inherited will show genes in progeny and parents as some. Human and flies have 60% of genome same. This similiarity of human Drosophila genomes helps to study behaviour, development and genetic diseases. So for studying specific genes

in Drosophila can also indicate the development in human. Fruit fley brain contains neurons and in complex manner which are similiar to human brain. Nerve impulses and neurotransmitters in fruit flies is as some as in humans. Also Drosophila act as model for learning and memory. It can be noticed by Olfactory Avoidance Experiments. In this experiment flies were exposed to a odor and given an electric shock. Then another odor is given and not given electric shock. The flies migrated towards second order odor when they forced to choose these a odors. It indicates that Drosophila can store the memory and learn Where to move when forced to choose the odor. so the memory and learning is happening in fruit flies like in humans. Due to 60% Similiarity between humans and flies, in genome, size at both of them have similiar behavioural in learning and memory. From Ancestors, they both retain the genes for learning and memory in Common.