Biology Past Paper PDF January 2024 - 12th Science

## Social Service League High School & Junior College, Parel ### Preliminary Examination January 2024 **January 2024** **Time: 3 Hours** **12th Science** **Marks: 70** ### Biology #### Section A **Q.1.** Select and write the correct answer for the following multiple-choice type of questions. (10...

## Social Service League High School & Junior College, Parel ### Preliminary Examination January 2024 **January 2024** **Time: 3 Hours** **12th Science** **Marks: 70** ### Biology #### Section A **Q.1.** Select and write the correct answer for the following multiple-choice type of questions. (10) | i. | Individuals having identical alleles of a gene are known as | |---|---| | A | homozygous | | B | heterozygous | | C | hybrids | | D | dominants | | ii. | is formed in angiosperms by triple fusion | |---|---| | A | testa | | B | integument | | C | endosperm | | D | suspensor | | iii. | Apical dominance: Auxin :: Fruit ripening? | |---|---| | A | gibberellin | | B | cytokinin | | C | ethylene | | D | abscissic acid | | iv. | In a fully turgid cell | |---|---| | A | T.P = O.P | | B | T.P > S.P | | C | O.P > S.P | | D | T.P = 0 (zero) | | v | animal group is more vulnerable to the process of extinction? | |---|---| | A | amphibian | | B | reptilia | | C | aves | | D | mammalia | | vi.| In lac operon, lactose acts as | |---|---| | A | inducer | | B | co-inducer | | C | repressor | | D | co-repressor | | vii. | Decrease in platelet count is called | |---|---| | A | thrombocytopenia | | B | thrombocytosis | | C | thrombokinase | | D | thromboplastin | | viii. | Respiratory organs in scorpion are | |---|---| | A | gills | | B | book lungs | | C | skin | | D | book gills | | ix. | Maximum transpiration occurs through | |---|---| | A | cuticle | | B | lenticels | | C | stomata | | D | bark | | x | Which hormone confirms pregnancy? | |---|---| | A | progesterone | | B | estrogen | | C | hCG | | D | LH | **Q. 2.**Answer the following questions in one sentence only: (08) i. What is Arthralgia? ii. Who coined the term biodiversity? iii. What is a Biofortified wheat variety with high protein content called? iv. What is superglue? v. what is 'Leukaemia'? vi. What is the relationship between tiger and deer is called? vii. Which is the first hormone to be discovered in plants? viii. What is the definition of Diffusion Pressure Deficit (D.P.D)? #### Section B Answer any EIGHT of the following questions. (16) Q 3 - Give reason for – The pyramid of biomass in the sea is inverted. Q 4 - Sketch and label the T.S. of the spinal cord. Q 5 - Milk starts to coagulate when Lactic Acid Bacteria (LAB) are added to warm milk as a starter. What are the two other benefits of LAB? Q 6- Why is transpiration called 'a necessary evil'? Q7-Write a short note on Golden Rice. Q 8 - Sketch and label – Electrocardiogram or ECG Q9 - What is the significance or function of – Transgenic Plants? Q 10 - Distinguish between - Food chain and Food web. Q 11-Match the column | Column I (Phenomena) | Column II (Effect) | |---|---| | 1 - Eutrophication | A- Soil Erosion | | 2- Biomagnification | B- Prevention of extinction | | 3- Conservation | C- Accumulation of non-biodegradable substance | | 4- Deforestation | D- Death of aquatic ecosystem | Q 12 - Distinguish between – Phenotype and Genotype Q 13 – Draw a labelled diagram of – clover leaf structure of t-RNA carrying Glutamic acid. Q 14 Write a short note on Bt cotton. #### Section C Answer any EIGHT of the following questions. (24) Q15 - Explain with suitable example an independent assortment. Q16- Distinguish between - Cerebrum and Cerebellum. Q17-What are the aims of human genome project? Q 18-Write a short note on Hypertension. Q19-What is the structure of blastocyst or blastulation? Q 20- What are the major changes that took place in the evolution of man? Q21 - What are different population attributes? Q22 What are different components of ecosystem? Q 23-Write short note on - Vernalization. Q 24-Write short note on - Applications of tissue culture. Q 25 Sketch and label the T.S. of undehisced anther. Q 26 Write a short note on Parthenocarpy. #### Section D Answer any THREE of the following questions. (12) Q 27- With help of suitable diagram, describe the conducting system of human heart? Q 28 - What are the outbreeding devices which encourage cross pollination? Q 29-What is vaccine? What are the advantages of oral vaccines or edible vaccine? Q 30-What is the process by which zygote divides and redivides to form the morula **OR** Write an account of cleavage during embryonic development in humans. Q 31 - Describe in brief an account of disorders of the thyroid **OR** What are the functional disorders of thyroid gland?