Question

hu 1. True or false? Phototropic bending occurs as a result of hormone-regulated growth inhibition. 2. What wavelength of light and what hormone is involved in the phototropic response of Avena sativa coleoptiles? 3. During germination, what shoot organ is involved in light detection in monocot vs dicot species? 4. True or false? Phototropins are flavoproteins that induce phototropic bending in Arabidopsis hypocotyls and Avena sativa coleoptiles. 5. What 2 hormones are involved in suppressing photomorphogenesis in the dark? 6. True or false? Inhibition of stem elongation is a phytochrome-controlled process. 7. What is the mesocotyl and what is its function? 8. What are the three key developmental changes observed when dark-grown seedlings are exposed to light (even a single flash of light)? 9. True or false? Phytochrome is a light-regulated protein kinase found in its pr state in the cytosol and the Pfr state is selectively imported into the nucleus. 10. True or false? Hook opening is regulated by phytochrome and auxin. 11. Define the following terms: proplastid, etioplast, chromoplast, chloroplast, leucoplast.

Answer 1

1. The phototrophic bending of light occurs due to the activity of a plant hormone called auxin.

Auxin in response to sunlight leads to the elongated growth of the cells on the shady side of the plant. As the plant cells on the side opposite to the light source keep on growing, so the plant bends towards the light source.

The given statement is half correct as the phototrophism occurs due to the activity of the hormone, auxin. But it does not lead to growth inhibition, instead the hormone leads to cell growth in the opposite side of the light source in the plant.

So the given statement is false.