CBSE Class 12 Biology Board Question Paper 2019 (Set-2)
This is the CBSE Class 12 Biology Previous Year Question Paper from the 2019 Main Exams, Delhi Set-2. The question paper comprises a total of 27 questions divided into four sections: Section A (questions 1-5, 1 mark each), Section B (questions 6-12, 2 marks each), Section C (questions 13-24, 3 marks each), and Section D (questions 25-27, 5 marks each). All questions are compulsory. While there is no overall choice, internal choices are provided in some questions across all sections, including two questions of 1 mark, two of 2 marks, four of 3 marks, and all three 5-mark questions. Students must attempt one alternative where choices are given. Neat and properly labelled diagrams are required where necessary. Solving this previous year paper is crucial for students to understand the exam pattern, question types, and marking scheme, thereby enhancing their preparation and performance in the board examinations.
Quick info
| Board | CBSE |
|---|---|
| Class | 12 |
| Subject | Biology |
| Session | 2019 |
| Language | English |
| Type | Previous Year Question Paper |
| Exam type | Board Exam |
Paper pattern
The question paper has 27 questions across four sections (A, B, C, D) with marks ranging from 1 to 5. Internal choices are available in specific questions within each section.
Topics covered
Paper topics
- Sewage Treatment
- Methanogens
- Charles Darwin
- Fitness
- Meiosis
- Haploidic Life Cycle
- Ozone Layer
- Stratosphere
- Symbiosis
- Orchid
- Forest Tree
Important topics
- Sewage treatment and flocs
- Darwin's concept of fitness
- Meiosis in haploidic life cycles
- Ozone layer and its location
- Population interactions
PDF preview
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Question paper text
Biology Question Paper 2019 (Set-2)
General Instructions:
- There are total 27 questions and four sections in the question paper. All questions are compulsory.
- Section A contains questions number 1 to 5, very short answer type questions of one mark each.
- Section B contains questions number 6 to 12, short answer type I questions of two marks each.
- Section C contains questions number 13 to 24, short answer type II questions of three marks each.
- Section D contains question number 25 to 27, long answer type questions of five marks each.
- There is no overall choice in the question paper, however, an internal choice is
provided in two questions of one mark, two questions of two marks, four questions of three marks and all the three questions of five marks. In these questions, an examinee is to attempt any one of the two given alternatives.
- Wherever necessary, the diagram drawn should be neat and properly labelled.
Question 1
What are 'flocs', formed during secondary treatment of sewage?
OR
Write any two places where methanogens can be found.
SOLUTION:
Flocs are masses of bacteria embedded in fungal filaments to form a mesh-like structure. These flocs consume organic matter in waste water and reduce the B.O.D. levels in water. The flocs form a part of activated sludge, a small part of which is pumped back into aeration tank to help as inoculums.
OR
Methanogens are found in cattle dung (gobar) and in rumen of cattle.
Question 2
How did Charles Darwin express 'fitness'?
SOLUTION:
Charles Darwin expressed 'fitness' as characteristics which enable some organisms to survive better in natural conditions (climate, food, physical factors, etc.) which would outbreed others that are less-endowed to survive under such natural conditions. Another word used is the fitness of the individual or population.
Question 3
At what stage does the meiosis occur in an organism exhibiting haploidic life cycle and mention the fate of the products thus produced.
SOLUTION:
Meiosis occurs at the zygote stage in an organism exhibiting haploidic life cycle. Thus, the product formed will be haploid spores.
Question 4
Name the layer of the atmosphere that is associated with 'good ozone'.
OR
Mention the term used to describe a population interaction between an orchid growing on a forest tree.
SOLUTION:
"Good Ozone" which is chiefly responsible for absorbing the harmful ultraviolet radiation of sun is present in stratosphere. OR
Frequently asked questions
What is this document?
This is the official CBSE Class 12 Biology Previous Year Question Paper from the 2019 Main Exams, Delhi Set-2, designed for board exam practice.
What is the structure of the 2019 Biology paper?
The paper has 27 questions divided into four sections: Section A (1 mark), Section B (2 marks), Section C (3 marks), and Section D (5 marks), with internal choices provided in some questions.
How does solving previous year papers help?
Solving previous year question papers helps students understand the board pattern, question difficulty, and marking scheme, improving their confidence and exam performance.
What is the total duration and marks for the exam?
The provided text mentions the number of questions and marks per section but not the total duration or maximum marks for the entire paper.
Are there choices available in the questions?
Yes, internal choices are provided in two questions of 1 mark, two of 2 marks, four of 3 marks, and all three 5-mark questions, allowing students to attempt one of the two alternatives.
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