Factors Affecting Plant Growth

Q.

Design an experiment to demonstrate hydrotropism.

Q. Can you think of more similar examples of a sigmoid curve? What kind of a curve can you expect in a tree showing seasonal activities?

Q. In a dihybrid cross, when one pair of alleles show incomplete dominance, genotypic ratios are

1. 3:6:3:1:2:1
2. 1:2:2:4:1:2:1:2:1
3. 1:2:1
4. 9:3:3:1

Q. Who discovered that sunlight is essential for the plant process which somehow purifies the air fouled by burning candles or breathing animals?

1. T.W Engelmann
2. Joseph Priestley
3. Jan Ingenhousz
4. Julius von Sachs

Q.

By prunning more branching occurs because due to it , axilla buds become sensitive for the

1)ethylene

2)GA

3)I.A.A

4)cytokinin

Q. Which of the following hormones can replace vernalization?

1. Ethylene
2. Gibberellin
3. Cytokinin
4. Auxin

Q.

Select the nutrient that is obtained from air by the plants

1. Potassium

2. Oxygen

3. Nitrogen

4. Phosphorus

Q. Assertion :- Oxygen is compulsory for growth of all organisms.
Reason:- Oxygen is must for releasing metabolic energy essential for growth.

1. Both assertion and reason are true and reason is the correct explanation of assertion
2. Both assertion and reason are true but reason is not the correct explanation of assertion
3. Both assertion and reason are false
4. The assertion is true but reason is false

Q. In sigmoid growth curve, the exponential phase slows down leading to a stationary phase due to

1. halting of respiration
2. genetic nature
3. limited nutrient supply
4. absence of differentiation

Q.

The figure shows two crops fields(plot A and B) have been treated by manures and chemical fertilizers, respectively, keeping other environmental factors the same. Observe the graph and answer the following questions.

1. Why does plot B show a sudden and gradual decrease in yield?
2. Why is the highest peak in plat A graph slightly delayed?
3. What is the reason for the different patterns of the two graphs?

Q.

Which one of the following has compound leaves? ​

1. Neem tree

2. Mango tree

3. Banyan tree

4. Papaya tree

Q. Which of the following is an example of pinnately compound leaf?

1. Cucumber
2. Papaya
3. Cucurbita
4. Neem

Q.

Few normal seedlings of tomato were kept in a dark room. After a few days, they were found to have become white-colored like albinos. Which of the following terms will you use to describe them?

1. Mutated

2. Embolised

3. Etiolated

4. Defoliated

Q.

What types of stress are plants exposed to?

Q.

Write a note on the banyan tree.

Q. A white-flowered Mirabilis plant (rr) was crossed with a red color flowered plant (RR). If 120 plants are produced in $F_2$ generation, the result would be

1. 90 Red and 30 white
2. 30 red and 60 pink and 30 white
3. 60 pink and 60 white
4. 30 red and 30 pink and 90 white

Q. The crossing of $F_1$ hybrid to one of its parents is known as _________.

1. test cross
2. back cross
3. out cross
4. reciprocal cross

Q. Growth is primarily affected by two climatic factors which are

1. light and temperature
2. light and soil nitrogen
3. wind and soil
4. Humidity and phytohormones

Q. Assertion: Plant growth and development is intimately linked with the water status of plant cells.
Reason: Guttation is the process of water loss from hydathodes.

1. Both assertion and reason are true and reason is the correct explanation of assertion
2. The assertion is true but reason is false
3. Both assertion and reason are true but reason is not the correct explanation of assertion
4. Both assertion and reason are false

Q. Statement 1: In $F_2$ generation of a monohybrid cross, the ratio of visible traits in offspring= 3:1
Statement 2: In $F_2$ generation of a monohybrid cross, both visible parental traits are expressed in the ratio of 3:1.
Choose the correct option.

1. Both the statements are correct
2. Statement 1 is correct and statement 2 is incorrect
3. Statement 1 is incorrect and statement 2 is correct
4. Both the statements are incorrect

Q. A heterozygous pea plant, that is tall with yellow seeds (TtYy), is allowed to self-fertilize. Which of the following will have the maximum identical genotypic combinations?

1. TTYy
2. TtYY
3. TtYy
4. Ttyy

Q. On selfing YyRr, a total of 400 plants were obtained. How many of these will have the genotype YyRr?

1. 100
2. 50
3. 225
4. 300

Q. Two independent monohybrid crosses were carried out involving a tall pea plant with a dwarf pea plant. In the first cross, the offspring population had equal number of tall and dwarf plants, whereas in the second cross it was different. Work out the crosses, and explain giving reasons for the difference in the offspring populations. [3]

Q. Which of the following is not an example for plant growth?

1. The length of a wooden log thrown in a river increases by 1 centimeter
2. Annual ring formation
3. Formation of cambium
4. A plant of 1m in length becomes a 2m long plant

Q.

Give any two reasons to justify that onion bulb is a modified stem.

Q.

Match of following columns

$\begin{array}{cc}\text{column-I}& \text{column-II}\\ \text{A.Water}& \text{1.Release of metabolic energy}\\ \text{B.Oxygen}& \text{2.Optimum enzymatic activity}\\ \text{C.Nutrients}& \text{3.Cell enlargement/turgidity}\\ \text{D.Temperature}& \text{4.Synthesis of protoplasm}\end{array}$

1. A - 3 , B - 4 , C - 2 , D - 1

2. A - 1, B - 2 , C - 3, D - 4

3. A - 4 , B - 3 , C - 2 , D - 1

4. A - 3 , B - 1 , C - 4 , D - 2

Q.

Primary andsecondary growth are inhibited by

1. auxin
2. gibberellins
3. abscisic actid
4. cytokinins

Q. Age of a tree can be estimated by

1. it’s height and girth
2. the number of annual rings
3. it’s biomass
4. the diameter of the heartwood

Q. A cross between two homozygous parents differing from one another by alleles at only one gene locus is

1. backcross
2. monohybrid cross
3. dihybrid cross
4. trihybrid cross

Q. Growth inhibitor hormone is

1. auxin
2. gibberellin
3. abscisic acid
4. naphthalene acetic acid