ISC 2019 Biology Practical Question Paper for Class 12

About this paper

This is ISC Class 12 Biology Paper 2 (Practical), code 863B, from the 2019 board examination set by CISCE. The footer reads 1219-863B. It carries 30 marks, runs for three hours plus fifteen minutes of reading time, and has five questions, all to be answered. Question 1 is a floral study of specimen D-41, including the ovary in transverse section, the floral formula and the family. Question 2 grinds specimen D-42 with salt and liquid detergent, heats it at 70 °C, and layers the filtrate with chilled 90% ethanol. Question 3 is a safranin-stained transverse section of D-43, Question 4 is spotting of specimens A to E, and Question 5 is the project (10 marks) and the Biology Practical File (5 marks). This copy has the questions only.

Exam

ISC Class 12

Subject

Biology Practical

Year

2019

Paper code

863B

Maximum marks

30

Time allowed

3 hours + 15 min reading

Questions

5

Pages

3

Answers included

No, questions only

Paper pattern

• Question 1

  5 marks

  Floral study of specimen D-41: longitudinal section, androecium, ovary in transverse section, floral formula, floral diagram and family

• Question 2

  3 marks

  Pulp of specimen D-42 extracted with salt and liquid detergent at 70 °C, then treated with chilled 90% ethanol

• Question 3

  2 marks

  Thin transverse section of specimen D-43, stained with safranin and mounted in glycerine

• Question 4

  5 marks

  Spotting: identify specimens A to E, with two reasons and a labelled diagram each; not more than three minutes a spot

• Question 5

  15 marks

  Project (10 marks) and Biology Practical File (5 marks), shown to the Visiting Examiner

Topics covered

• Floral morphology
• Androecium and gynoecium
• Floral formula and floral diagram
• Extraction with salt, detergent and chilled ethanol
• Plant anatomy
• Specimen spotting

Questions from this paper

1. Describe the floral characteristics of specimen D-41 in semi-technical terms, and record the relationship of the stamens, their number, and the nature of the anthers.
2. Write the floral formula and draw the floral diagram of D-41. Name its family and two characteristic features of that family.
3. Mention the botanical name, genus and species, of one economically important plant of the family you named for D-41.
4. Specimen D-42 is pulped, mixed with salt and liquid detergent, held at 70 °C, and the filtrate is layered with chilled 90% ethanol. Name the structure that becomes visible, and state why the detergent and the chilled ethanol are used.
5. Cut a thin transverse section of specimen D-43, stain it with safranin, mount it in glycerine, and identify it with two reasons.
6. Identify specimens A to E. Give two reasons for each identification and draw a labelled diagram. Do not spend more than three minutes on a spot.