Genetic Diversity and Mutations

Gene Mutations

If you have ever read a comic book or watched a movie about superheroes, then you are probably familiar with the term mutation. Many of the superheroes in these stories have powers resulting from genetic mutations. Mutations affect the phenotype of an organism. However, unlike those found in comics and movies, the mutations you will learn about now do not involve superhuman abilities.

Genetic mutations occur during DNA replication, which involves enzymes that “proof-read” strands of mRNA and DNA. Sometimes these enzymes miss mistakes in the code, and the resulting change in the organism’s DNA is referred to as a mutation. Such mutations can affect a single gene or change an entire chromosome. In this interactivity, you will learn specifically about point mutations. Click the player button to begin.

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Chromosomal Mutations

The effects of chromosomal mutations vary. While some mutations are harmful, or even lethal, other mutations can benefit the organism. The effect of the mutation depends on how many genes are affected and the location of the mutation on the chromosome. In some cases, chromosomal mutations can be inherited by offspring. In this interactivity, learn about the different types of chromosomal mutations. Click the player button to begin.

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Mutations can happen in the DNA of somatic cells or in the DNA of gametes. Somatic cell mutations are passed on to daughter cells in the organism via mitosis, but they are not passed on to other organisms. When the mutations occur in the gametes of organisms, they are passed on to the next generation, and will appear in the cells of the offspring.

Environmental Mutagens

Mutations occur because of environmental mutagens. Mutagens are agents that cause mutations. Some of these mutagens include chemicals and types of radiation, including UV radiation, that change the chemical structure of the nitrogen bases of DNA nucleotides. In this interactivity, learn about several different environmental sources of mutagens. Click the player button to begin.

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Not all mutations are harmful, and many have been beneficial to species, allowing them to adapt to changing environmental conditions. Because bacteria reproduce so quickly, the effects of mutations can be studied over many generations to determine the cost or benefit of the mutation. Various microbial populations have been observed to adapt to different conditions such as temperature changes or nutrient sources as a result of beneficial mutations. Mutations allow for genetic diversity to occur in a species, which is important for species to be able to adapt to changing conditions.

 

Genetic Diversity and Mutation Review

Now that you investigated genetic diversity and mutation, review your knowledge. In this non-graded activity, read each question and select the correct response. Click the player button to get started.