What causes a green plant exposed to the light, on only one side, to bend towards the source of light as it grows ?
Correct answer: B. Auxin accumulates on the shaded side, stimulating greater cell elongation there
- A. Light stimulates plant cells on the lighted side to grow faster
- B. Auxin accumulates on the shaded side, stimulating greater cell elongation there
- C. Green plants need light to perform photosynthesis
- D. Green plants seek light because they are phototropic
Explanation
Auxins induce cell elongation. In a differentially illuminated plant, they accumulate in the shaded part, causing elongation of the cells in the shaded part. This unequal elongation on two sides lags the Exponential (or Log) phase causing the plant to curve or bend towards the light source i.e., phototropic curvature.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? support@testustad.com
About Growth and Development
Embryonic development covers fertilization, cleavage, formation of the blastula and gastrula, germ layers, organ formation and differentiation. Regeneration describes the replacement of lost tissues or body parts, whereas ageing involves gradual cellular and physiological changes linked to reduced repair, altered metabolism and declining organ function.
Practise Growth and Development
230 free Growth and Development MCQs from Biology, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Biology questions like this
Biology is on 8 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
More Growth and Development questions
The Avena Curvature is used for bioassay of :
Phytochrome is a :
You are given tissue with its potential for differentiation in artificial culture. Which of the following pairs of hormones would you add to the medium to secure shoots as well as roots?
Typical growth curve in plants is :
A few normal seedlings of tomato were kept in a dark room. After a few days, they were found to have become white-coloured like albinos. Which of the following terms will you use to describe them?
Which one of the following growth regulators is known as 'stress hormone' ?