SAMPLE QUESTION PAPER (2021-22)
BIOLOGY (044)
TERM II
CLASS 12
Time: 2 Hrs Max. Marks: 40
GENERAL INSTRUCTIONS
i. All questions are compulsory.
ii. The question paper has three sections and 13 questions. All questions are compulsory.
iii. Mark distribution:
a. Section–A has 6 questions of 2 marks each
b. Section–B has 6 questions of 3 marks each
c. Section–C has a case-based question of 5 marks.
iv. There is no overall choice. However, internal choices have been provided in some questions. A student has to attempt only one of the alternatives in such questions.
v. Wherever necessary, neat and properly labelled diagrams should be drawn.
SECTION A
Attempt all questions: –
Q.1 Sometimes red coloured itchy spots appear on the skin. What are these spots called in general terms? Under what conditions a person can get such an infection?
Q.2. Increase in human population and motorization have its own issues of resource utilization. At the end of the day, a lot of environmental issues crop up. How the figure given below help to sort out the problem?
OR
The introduction of lady bird beetle is a beneficial methodology for agriculture / horticulture. Mention two points to justify the statement.
Q.3. How vaccination does save us from possible infections during pandemic?
Q.4. Species area relationship is a good indicator of diversity of an ecosystem. If the value of Z is 0.7 for area A, and 0.15 for area B, which area has higher species richness and a steeper slope?
Q.5. An ecologist study an area with species A, thriving on unlimited resources and showing exponential growth, introduced species B and C to the same area. Consider two situations:
a. Species B depends on the same resources as that of A, but population C do not.
b. Species B with status as that of population C (Status of C remains unchanged) but both do not share same time of the day.
What will be the effect on the growth pattern of the species A, B and C when living together in the same habitat?
Q.6. How Connell did explain the change in species composition of an area?
OR
Over the past few decades, with the increase in warming at the global level, out of the regulators and the conformers, which of the two will have better chances of survival? Give two adaptations that support them to survive in the ambient environment? Give one suitable example.
SECTION B
Q.7. The cases of cancerous growth are more prevalent in the society these days. How do normal cells get transformed into cancerous cells? Give three examples of non-food items that are considered as contributing factors.
OR
A patient reported for persistent fever and loose motions, although no specific reason could be pin pointed by the doctor. What did the doctor finally suspected? Which test helped the doctor to reach conclusion? Give two other symptoms that could also be visible.
Q.8. How the mother provides protection against infections to a new born baby. Under which category of protective mechanisms it does come. If the mother does not follow this process after delivery, how could this affect the health of baby during first few years?
Q. 9. What are Transformants? What procedure is applied to identify the transformants in the culture medium?
Q.10 ‘The Evil Quartet’ is a well-established term in the field of ecology. Explain how the population of organisms is affected by it.
Q.11 In the following figure three points A, B, C have been demarcated with A denoting Delhi, B denoting Faridabad and C denoting Agra. Water samples were collected from the three locations. The BOD levels of samples A, B and C were 400 mg/L, 480 mg/L and 20 mg/L respectively.
a. What is this indicative of?
b. Why the BOD level gets reduced considerably at the collection point at the start of Agra?
c. Do you expect any variation in the values while on course through Agra.
d. What effect will it have on Taj Mahal in Agra?
Q.12 The image below depicts the result of gel electrophoresis. The loading of sample is indicated at the top.
a. The top portion of the gel corresponds to which electrode?
b. What inference can you draw from the sample III & IV?
c. DNA is invisible to naked eye, then how it becomes visible here?
SECTION C
Q.13 Some of the diseases are inborn and practically there is no medicine to cure them.
The advancement in science & technology has provided some possible approaches that could be adopted in order to either reduce the morbidity or to prevent mortality. This approach came into lime light during the year 1990, when it was successfully applied on a 4-year girl.
a. The above paragraph pertains to which technique?
b. The reported case was of which disease?
c. What intervention was planned by this technique?
d. Why it was felt that repeated procedures will be required for the girl?
e. What was thought to make it just one-time procedure for permanent cure?
OR
GM crops especially Bt crops are known to have higher resistance to pest attacks. To substantiate this, experimental study was conducted in 4 different farmlands growing Bt and non Bt-Cotton crops. The farm lands had the same dimensions, fertility and were under similar climatic conditions. The histogram below shows the usage of pesticides on Bt crops and non-Bt crops in these farm lands.
a. Which of the above farm lands have used the concepts of biotechnology in a better way?
b. Which of the above farm lands has depicts poor management practices?
c. As a farmer, which crop (GM / non GM) would you prefer and why?
d. In a separate experimental study, cotton bollworms were deliberately introduced in two farm lands where no pesticide was used. Explain what effect would a Bt and Non Bt crop have on the pest.