Plus One Botany Model Question Papers Paper 4

Plus One Botany Model Question Papers Paper 4 is part of Plus One Botany Previous Year Question Papers and Answers. Here we have given Plus One Botany Model Question Papers Paper 4

Plus One Botany Model Question Papers 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.

Question 1.
The class of fungi known as imperfect fungi is ……

Question 2.
Which one of the plant growth regulators induce immediate stomatal closure in leaves.

Question 3.
By observing the relationship of the first pair, fill in the blanks of the second pair
Auxins : Apical dominance
____: Overcome apical dominance

Question 4.
The reaction center of photosystems in green plants during light reaction is ……
a. Xanthophyll
b. Carotenoids
c. Chlorophyll b
d. Chlorophyll a

Answer any seven from question numbers 5 to 13. Each carries two scores.

Question 5.
Match the following:

Question 6.
Complete the diagram by filling the gaps.

Question 7.
Suggest a method for identification of stem and root in plants based on the arrangement of protoxylem.

Question 8.
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.

Question 9.
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’.

Question 10.
Observe the given diagram. Analyze this diagram and explain the structure of plasma membrane.

Question 11.
Write any two distinguishing features of the algal class Rhodophyceae.

Question 12.
There is a clear division of labour within the chloroplast. Substantiate the given statement with an explanation stating two points.

Question 13.
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.

Question 14.
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.

Question 15.
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.

Question 16.
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.

Question 17.
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.

Question 18.
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.

Answers

Answer 1.
Deuteromycetes

Answer 2.
Abscissic acid

Answer 3.
Cytokinin

Answer 4.
d. Chlorophyll a

Answer 5.
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.

Answer 6.
4C – Oxyloacetic acid
4C – Malic acid/ fumaric acid
5C – α-Ketoglutaric acid

Answer 7.
In root, the protoxylem are in exarch arrangement, while in stem, endarch.

Answer 8.
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.

Answer 9.
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.

Answer 10.
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.

Answer 11.
• The members of Rhodophyceae are known as red algae.
• The food is stored as floridean starch.

Answer 12.
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.

Answer 13.
In this plant, the symptoms are mosaic formation, leaf rolling and curling, yellowing and veinclearing, dwarfing and stunted growth.

Answer 14.
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.

Answer 15.
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

Answer 16.
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.

Answer 17.
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.

Answer 18.
a. Vascular cambium and cork cambium.
b. From vascular cambium: Secondary xylem, secondary phloem, secondary medullary rays dulps.
From cork cambium: Phellem, phelloderm

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