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Class 11 Plant Growth and Development worksheet
CBSE Biology. Growth rates, plant hormones, photoperiodism and vernalisation. Every sheet has 20 questions in three sections and an answer key, and the numbers change every time.
Sample questions
Real questions from this chapter, as the app sets them. Tap Answer to see the answer and working.
Section A · multiple choice
- 1.
The plant hormone that promotes cell division is:
- abscisic acid
- ethylene
- auxin
- cytokinin
Answer
(d) cytokinin
- 2.
Which plant hormone promotes cell division?
- Abscisic acid
- Ethylene
- Cytokinin
- Gibberellin
Answer
(c) Cytokinin
- 3.
Leaf A grows from 4 cm² to 5 cm² and leaf B from 10 cm² to 11 cm² in the same day. Which has the higher relative growth rate?
- Both are equal
- Leaf B
- Leaf A
- Cannot be told
Answer
(c) Leaf A
relative growth rate = 1 ÷ starting size: A 25%, B 10% a day
Section B · short answer
- 4.
What is the difference between arithmetic and geometric growth?
Answer
In arithmetic growth only one daughter cell keeps dividing, so growth is a constant amount each time (a straight line, Lt = L0 + rt). In geometric growth both cells keep dividing, so growth speeds up (an S-shaped curve when nutrients become limited).
- 5.
Give two effects of ethylene.
Answer
Promotes female flowers in cucumber; Causes leaf and flower abscission
Section C · long answer
- 6.
Describe arithmetic and geometric growth, with their equations and growth curves.
Answer
Arithmetic: after mitosis one daughter cell divides and the other differentiates; growth is linear, Lt = L0 + rt (a root growing at a constant rate). Geometric: both daughter cells divide; W1 = W0 e^(rt), where r is the relative growth rate; growth starts slowly (lag phase), then fast (log or exponential phase), then slows as nutrients run short (stationary phase), giving an S-shaped (sigmoid) curve.
Fresh sheets for your child
In the app, every Plant Growth and Development sheet is new: the app remembers the questions your child has already had and leaves them out. Print the sheet as a PDF, or use notebook mode and write the answers in a notebook.
Coming soon for Android and iPhone.