Kerala Plus One Botany Model Question Paper 4
Time: 1 Hours
Cool off time : 10 Minutes
General Instructions to candidates :
- There is a ‘cool off time’ of 10 minutes each for Botany and Zoology in addition to the writing time ‘ of 1 hour each. Further there is a ‘ 5 minutes’ ‘preparatory time’ at the end of the Botany Examination and before the commencement of the Zoology Examination.
- Use the ‘cool off time’ to get familiar with the questions and to plan your answers.
- Read the instructions carefully.
- Read questions carefully before you answering.
- Calculations, figures and graphs should be shown in the answer sheet itself.
- Malayalam version of the questions is also provided.
- Give equations wherever necessary.
- Electronic devices except non programmable calculators are not allowed in the Examination Hall.
Answer all questions from question numbers 1 to 4. Each carry one score.
The class of fungi known as imperfect fungi is ……
Which one of the plant growth regulators induce immediate stomatal closure in leaves.
By observing the relationship of the first pair, fill in the blanks of the second pair
Auxins : Apical dominance
____: Overcome apical dominance
The reaction center of photosystems in green plants during light reaction is ……
c. Chlorophyll b
d. Chlorophyll a
Answer any seven from question numbers 5 to 13. Each carries two scores.
Match the following:
Complete the diagram by filling the gaps.
Suggest a method for identification of stem and root in plants based on the arrangement of protoxylem.
A cell with a chromosome number 42 undergoes mitosis and another cell with 42 chromosomes undergoes meiosis. Give the chromosome number of daughter cells after mitosis and meiosis. Give reasons for your answer.
Observe the diagrammatic view of a cell and answer the questions.
a. Identify the phase in which DNA synthesis takes place.
b. Mention any one event that takes place in the stages marked as ‘X’ and ‘Y’.
Observe the given diagram. Analyze this diagram and explain the structure of plasma membrane.
Write any two distinguishing features of the algal class Rhodophyceae.
There is a clear division of labour within the chloroplast. Substantiate the given statement with an explanation stating two points.
Botany teacher brought a diseased plant in the classroom. Manoj identified the pathogen as a virus. Can you list any two symptoms of diseases, that helped him to identify the pathogen?
Answer any four from question numbers 14 to 18. Each carries 3 scores.
Three potato pieces of equal weight (2g) were left in three types of solutions (A, B and C) overnight. The weight change of potato pieces are as shown in the figure.
a. Identify the solutions A and C.
b. Discuss the reason for not having any change in the piece put in solution B.
C4 plants are adapted to overcome a wasteful process found in C3 plants and hence productivity and yields are better in these plants.
a. Name the wasteful process found in C3 plants.
b. Identify the cells involved in the C4 pathway.
c. Write any two differences between C3 plants and C4 plants.
Plants that are adapted to dry tropical regions have a special type of Co2 fixation in addition to the C3 cycle.
a. Name this pathway.
b. Can you identify any specialty in the leaf anatomy of such plants? If so, what is this anatomy called?
c. Which is the primary Co2 acceptor in this pathway?
d. Write any one advantage of such plants over C3 plants.
In most of the plants, roots are meant for absorption and fixation. But there are exceptions to these functions. Justify the statement citing at least three examples.
In a dicotyledonous stem, secondary growth takes place at two regions by the activity of two lateral meristems.
a. Identify the two lateral meristems.
b. List the new tissues formed from each of these meristems.
d. Chlorophyll a
a. Synthesis and storage of energy – Mitochondria.
b. Packaging and delivery of materials – Golgi apparatus.
c. Digestion of intercellular materials – Lysosome.
d. Formation of basal body of cilia and flagella – Centriole.
4C – Oxyloacetic acid
4C – Malic acid/ fumaric acid
5C – α-Ketoglutaric acid
In root, the protoxylem are in exarch arrangement, while in stem, endarch.
After mitosis chromosome doesn’t change. Because its division doesn’t cause any decrease in amount of chromosome. But meosis is known as reduction division. So it bring half of the chromosome number.
a. DNA division occurs at S-phase.
b. X – Metaphase: During which chromosome align at metaphase plate.
Y – Anaphase: Centromere of the sister chromatids split and chromatids separate. Chromatids move to opposite poles.
Fluid – mosaic model. According to this model quasi-fluid nature of lipid enables lateral movement of proteins within the overall bilayer. This ability to move within the membrane is measured as its fluidity. This fluid nature of the membrane is also important from the point of view of function like cell growth.
• The members of Rhodophyceae are known as red algae.
• The food is stored as floridean starch.
Within the chloroplast there is the membranous system consisting of grana, the stroma lamellae, and the fluid stroma. There is a clear division of labour within the chloroplast. The membrane system is respon¬sible for trapping the light energy and also for the synthesis of ATP and NADPH.
In this plant, the symptoms are mosaic formation, leaf rolling and curling, yellowing and veinclearing, dwarfing and stunted growth.
a. A – Hypertonic, C – Hypotonic
b. B – Solution is isotonic. The osmotic pressure of the external solution and cell sap are same. Hence no net flow of water towards inside or outside of potato pieces.
a. Photo respiration
b. Bundle sheeth cells around the vascu lar bundles.
c. C3 cycle C4 cycle
1. Co2 accepter is Co2 accepter is PEP RuBp
2. The enzyme – The enzyme involved
RUBISCO – PEP case
a. C4 Pathway or Hatch and Slack pathway.
b. Yes. Kranz anatomy.
c. Phosphoenol pyruvate (PEP).
d. In C4 plants photorespiration is absent so the productivity is high.
Roots are modified for:
Storage of food: Tap roots of carrot, turnip and adventitious roots of sweet potato, get swollen and store food.
Respiration: Roots modified for physiological function like breathing are called breathing roots or pneumato phores. eg., Mangrove rees.
For mechanical support: Prop roots/ pillar roots of banyan trees are developing from the aerial branches and it grows vertically downwards.
a. Vascular cambium and cork cambium.
b. From vascular cambium: Secondary xylem, secondary phloem, secondary medullary rays dulps.
From cork cambium: Phellem, phelloderm