Most organisms display a circadian rhythm, a cycling of ...

Question

Most organisms display a circadian rhythm, a cycling of biological processes that is roughly synchronized with day length (e.g., jet lag occurs in humans when rapid movement between time zones causes established circadian rhythms to be out of synch with daylight hours). In Drosophila, pupae eclose (emerge as adults after metamorphosis) at dawn.

In most plants, such as Arabidopsis, genes whose encoded products have roles related to photosynthesis have expression patterns that vary in a circadian manner. Using this knowledge, how would you screen for Arabidopsis mutants that have an impaired circadian rhythm?

Accepted Answer

Hey, everyone. Let's take a look at this question together. Fragile X syndrome is the most common inherited cause of intellectual disability and is more common in males than females. Symptoms may include delayed development of speech and language, social anxiety, hyperactivity, attention deficits and sensory disorders. Fragile X syndrome is caused by a mutation in the blank on the X chromosome. Is it the F eight gene? The F nine gene, F M R one gene or the C F T R gene? Let's work this problem out together to try to figure out which of the following genes when mutated cause Fragile X syndrome. So looking at our answer choices, we can see answer choice. D says C F T R gene, which we note that the C F T R gene is the cystic fibrosis, transmembrane conductance regulator gene and is associated with cystic fibrosis and not Fragile X syndrome. So, answer choice D can be eliminated. And we also know that the protein that is responsible for normal brain development and function is the F M R one protein, which the F M R one protein is coded for by the F M R one gene. And in that F M R one gene mutations in the gene can lead to abnormal brain development and function such as delayed development of speech and language, as well as social anxiety, hyperactivity, attention deficits and sensory disorders, which describes that fragile X syndrome and so fragile X syndrome is caused by a mutation in the F M R one gene. So answer choice C is the correct answer. Since the protein that is responsible for normal brain development and function is that F M R one protein which is coded by that F M R one gene. And the mutations in that gene will result in fragile x syndrome. So answer choice C is the correct answer. I hope you found this video to be helpful. Thank you and goodbye.

Key Concepts

Circadian Rhythm

Genetic Screening

Gene Expression Patterns

Watch next