Question

Which of the following statements most accurately describes the transposable genetic elements found in corn?

a) Transposable elements found in maize are strictly autonomous.

b) The earlier in kernel development a reversion event occurs, the larger the spot of tissue exhibiting the reversion phenotype.

c) Transposons in corn lack inverted repeats.

d) Transposable elements are found only in corn.

Answer 1

Transposons in corn are not strictly autonomous. There are autonomous and non-autonomous transposons. Transposons have inverted repeat sequences at their ends and encode the enzyme transposase.

Step-by-step explanation:

Transposable elements, or transposons, are genetic elements that can move within the DNA of an organism. In maize (corn), transposons were first discovered by Barbara McClintock in the 1940s. They have since been found in various organisms. Transposons have inverted repeat sequences at their ends and encode the enzyme transposase. They allow the DNA sequence to excise from one location and integrate into another through transposition. Transposons in corn are not strictly autonomous. There are autonomous transposons, which have all the features necessary for mobility, and non-autonomous transposons, which lack some of the required enzymes and can only transpose with the assistance of an autonomous transposon.