FIRST YEAR HIGHER SECONDARY
MODEL EXAMINATION, FEBRUARY 2024
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PART-A: BOTANY
I. Answer any 3 questions from 1 to 4. Each question carries 1 score. (3x1=3)
(a) Light absorption
(b) Water splitting
(c) Biosynthesis of glucose
Colourless plastids: ________.
(a) Gemmae
(b) Protonema
(c) Prothallus
II. Answer any 9 questions from 5 to 15. Each question carries 2 score. (9x2=18)
(b) Write two examples.
(a) Plant growth promoters are a group of plant growth regulators that are involved in growth-promoting activities like cell division, cell enlargement, and flowering.
(b) Auxins and Gibberellins.
(b) Name the most common respiratory substrate.
(a) Respiratory substrates are the organic compounds that are oxidized during the process of respiration to release energy.
(b) Glucose (Carbohydrates).
(b) Give reasons.
(a) Bryophytes.
(b) They are called amphibians of the plant kingdom because these plants can live in soil but are dependent on water for sexual reproduction (fertilization).
(b) What is meant by respiratory climactic?
(a) Ethylene.
(b) Respiratory climactic is a sharp rise in the rate of respiration during the ripening of certain fruits.
(b) What is the most important event that takes place in the 'S' phase?
(a) The quiescent stage (G0) is a stage where cells that do not divide further exit the G1 phase to enter an inactive stage, though they remain metabolically active.
(b) DNA replication/synthesis occurs, where the amount of DNA per cell doubles.
• It is used in polishing.
• It is used in the filtration of oils and syrups.
(b) Internal factors which affect the rate of photosynthesis?
(a) It states that if a chemical process is affected by more than one factor, then its rate will be determined by the factor which is nearest to its minimal value.
(b) Number, size, age and orientation of leaves, mesophyll cells and chloroplasts, internal CO₂ concentration and chlorophyll content.
• Metaphase: Chromosomes are moved to the spindle equator and get aligned along the metaphase plate through spindle fibres to both poles.
• Anaphase: Centromeres split and chromatids separate; chromatids move to opposite poles.
Radial vascular bundle
Endarch Xylem
Conjoint vascular bundle
Exarch Xylem.
| STEM | ROOT |
|---|---|
| |
| STEM | ROOT |
|---|---|
| Conjoint vascular bundle | Radial vascular bundle |
| Endarch Xylem | Exarch Xylem |
(b) Photorespiration not occur in C₄ plants? Why?
(a) Photorespiration is a light-dependent process in C₃ plants where RuBisCO binds with O₂ instead of CO₂, leading to a waste of energy without producing ATP or sugars.
(b) C₄ plants have a mechanism that increases the concentration of CO₂ at the enzyme site, ensuring RuBisCO functions as a carboxylase and preventing the oxygenase activity.
(a) Open Vascular bundle
(b) Closed Vascular bundle.
(a) Open: Vascular bundles possess cambium between phloem and xylem, allowing for secondary growth.
(b) Closed: Vascular bundles do not have cambium, hence they do not form secondary tissues.
III. Answer any 3 questions from 16 to 19. Each question carries 3 score. (3x3=9)
(a) Identify four types of chromosomes based on centromere observed in figures A, B, C, D.
(b) What is Satellite?
(a) A-Metacentric, B-Sub-metacentric, C-Acrocentric, D-Telocentric.
(b) Some chromosomes have non-staining secondary constrictions at a constant location. It is called satellite.
(b) How much is the RQ of carbohydrates which are used as substrate?
(a) Respiratory Quotient (RQ) is the ratio of the volume of CO₂ evolved to the volume of O₂ consumed during respiration.
(b) RQ = 1.
(b) Write the type of placentation observed in figures (1), (2), (3), (4).
(a) Placentation is the arrangement of ovules within the ovary.
(b) (1) Marginal, (2) Axile, (3) Parietal, (4) Free central.
• Biosynthetic phase
• Photochemical phase
• ATP and NADPH utilized
• Take place in stroma
• ATP and NADPH produced
• Take place in grana.
| Light reaction | Dark reaction |
|---|---|
| |
| Light reaction | Dark reaction |
|---|---|
| Photochemical phase | Biosynthetic phase |
| ATP and NADPH are produced | ATP and NADPH are utilized |
| Take place in grana | Take place in stroma |
PART-B: ZOOLOGY
I. Answer any 3 questions from 1 to 5. Each question carries 1 score. (3x1=3)
II. Answer any 9 questions from 6 to 16. Each question carries 2 score. (9x2=18)
(A) Collar cell: Porifera; Cnidoblast: ________
(B) Cycloid scales: Osteichthyes; Placoid scales: ________
(C) Annelida: Coelom; Platyhelminthes: ________
(D) Parapodia: Annelida; Radula: ________.
(A) Coelenterata (Cnidaria).
(B) Chondrichthyes.
(C) Acoelomate
(D) Mollusca.
(a) Identify the organism.
(b) Name the class.
(c) Write any two salient features of the class.
(a) Pristis (Saw fish).
(b) Chondrichthyes.
(c) They have a cartilaginous endoskeleton and their skin is covered with placoid scales.
(b) Write about any two types of Co-factors.
(a) Co-factors are non-protein constituents that are bound to an enzyme to make the enzyme catalytically active.
(b) Two types include Co-enzymes (organic compounds) and Metal ions (form coordination bonds).
Birds, Bony fishes, Reptiles, Aquatic amphibians.
Ammonotelic: Bony fishes and Aquatic amphibians.
Uricotelic: Birds and Reptiles.
(a) Nitrogen bases 'A' and 'B'.
(b) Write the nucleosides of these nitrogen bases.
(a) A-Adenine, B-Uracil.
(b) A-Adenosine, B-Uridine.
(Bundle of His, Ventricles, Purkinje fibres, AV node)
SA node → ________.
| A | B |
|---|---|
| Neutrophil | Immune response of body |
| Basophil | Allergic reactions of body |
| Eosinophil | Secrete histamine, serotonin |
| Lymphocyte | Phagocytic |
| A | B |
|---|---|
| Neutrophil | Phagocytic |
| Basophil | Secrete histamine, serotonin |
| Eosinophil | Allergic reactions of body |
| Lymphocyte | Immune response of body |
(a) Identify A and B.
(b) Name any 1 subunit each of A and B.
(a) A- Actin, B-Myosin.
(b) Subunits of Actin: G actin. Subunits of Myosin: Meromyosin.
(a) What does A and B represent?
(b) Name any two steroid hormones.
(a) A-Hormone-receptor complex, B-Genome (DNA).
(b) Estrogen and Progesterone.
(a) Do you agree? Give reason.
(b) Distinguish between aestivation and hibernation.
(a) Yes, I agree. Frogs are ureotelic because they excrete urea as their main nitrogenous waste product.
(b) Aestivation is summer sleep, while Hibernation is winter sleep.
III. Answer any 3 questions from 17 to 20. Each question carries 3 score. (3x3=9)
(i) Which diagram represents coelomate condition?
(ii) Name one phylum having pseudocoelomate condition.
(iii) Write one example for acoelomate animal.
(i) Diagram A.
(ii) Aschelminthes.
(iii) Tapeworm (Platyhelminthes).
(a) Identify the graph.
(b) Write any two factors that affect this.
(c) Write the significance of this graph.
(a) Oxygen dissociation curve.
(b) Partial pressure of O₂, Partial pressure of CO₂, H⁺ concentration, and temperature.
(c) Useful in studying the effect of pCO₂ and H⁺ concentration on O₂ binding with haemoglobin.
(a) Glomerular Filtration: Blood filtered through glomerular capillaries.
(b) Reabsorption: 99% of filtrate reabsorbed by renal tubules.
(c) Tubular Secretion: Tubular cells secrete H⁺ and K⁺ to maintain ionic balance.
(b) Write function of:
(A) Na⁺-K⁺ pump
(B) Hypothalamus
(C) Medulla.
(a) Dura mater, Arachnoid mater, and Pia mater.
(b) (A) Maintains resting potential.
(B) Controls body temp/hunger.
(C) Controls respiration/gastric secretions.