Questions
If a plant cell is placed in deionised water, the water potential of that cell becomes
- more positive because the pressure potential becomes more positive
- more positive because the osmotic potential becomes more negative
- more negative because the pressure potential becomes more negative
- less negative because the pressure potential becomes more positive
Which of the following is/are incorrect about nastic movement?
P. It is a paratonic movement.
Q. It occurs due to change in turgor pressure as well as differential growth.
R. Nyctinasty is an example of nastic movement.
S. It is induced by endogenous stimulus.
- P
- S
- P and Q
- P and R
To break dormancy in a seed with a rudimentary embryo one should
- soak the seeds to remove inhibitors
- break the seeds to remove inhibitors
- germinate the seeds under red light to promote germination
- none of these
Which of the following is false about vernalisation?
- Site of perception of vernalisation stimulus is stem apex.
- Vernalisation does not induce flowering but prepares the plants for flowering.
- Low temperature affects germination.
- Genetic makeup is not changed by the cold temperature treatment.
Which statement about photomorphogenesis is false?
- It involves the protein pigment phytochrome.
- It is only important at the seedling stage of plant development.
- It is affected by red, far-red and blue light.
- It can be defined as light-dependent changes in plant growth and development.
Phototropins
P. are blue-light receptors
Q. include phototropism
R. are autophosphorylating protein kinases
S. absorb red light and undergo phosphorylation
- P, Q and R
- P, R and S
- P, Q and S
- Q, R and S
Which of the following is a false statement?
- All NH4+ seems to be converted first into the amide group of glutamine.
- Conversion of organic nitrogen to NH4+ by soil microbes is called ammonification.
- Cl– is required for photochemical reaction involved in photolysis of water.
- Plant roots absorb ions as well as the salts.
Which of the following is incorrect about ethylene?
- It promotes elongation of stems and root, especially in dicot.
- Its biosynthesis involves the enzyme ACC synthase.
- It promotes flowering in Bromeliads (the pineapple family).
- It enhances lateral or radial expansion of cell.
Which of the following statements are correct?
P. Water potential is a measure of the free energy of water per unit volume.
Q. Water potential is influenced by concentration, pressure and gravity.
R. An open beaker full of pure water at 20°C has 0 MPa water potential value.
S. Water in plants moves from higher to lower water potentials.
- P and Q
- P and S
- Q, R and S
- P, Q, R and S
How does a plant accumulate ions from the soil, which has a lower concentration than that in the plant?
- It applies pressure to push ions outside the cell.
- It applies pressure to push ions into the cell.
- It expends energy to transport ions against the concentration gradient.
- Its roots grow around soil particles trapping the ions in a cell.
In the experiment of photosynthesis, the isotope used by Calvin was
- O18
- C14
- C11
- N14
The first acceptor of carbon dioxide in C4 plant is
- malic acid
- aspartic acid
- oxaloacetic acid
- phosphoenol pyruvic acid
Which of the following is not a part of the triple response of etiolated pea seedling to ethylene?
- Stunted growth
- Increased radial expansion of cells of the stem
- Loss of gravity perception
- Unfolding of the apical hook of the seedling
An efficient root-inducing chemical useful in horticulture is
- GAA
- IBA
- NAA
- 2, 4 – D
Which of the following plant hormones is incorrectly paired with its function?
- Auxins – Responsible for apical dominance
- Abscisic acid – Regulates the rate of transpiration
- Cytokinins – Delay senescence
- Gibberellins – Promote bud and seed dormancy