MODEL PAPER 1 Biology - MODEL PAPER 1

In Gel Electrophoresis, fragments are moved from:


1. Anode to Cathode
2. Cathode to Anode
3. Negative to Positive
4. Positive to Negative

Which one of the following helps in absorption of phosphorus from soil by plants?

In the pedigree analysis, the symbol shown below represent

Bacteria and fungi in a forest ecosystem are generally:

Picture shown below is an example of:-

What is LAB? What is its role in human stomach?

Write the various major steps of fermentation.

In the given figure, give the name and functions of parts labelled A and B.

i. Given below is a TS of an apple. Identify A, B, and C.

ii. Why is an apple categorised as a false fruit?

The flow of genetic information is shown below. Name the process of (a) and (b).

Alien species invasion has been a threat to biodiversity. Justify with the help of a suitable example. List any other three causes responsible for such a loss.

What are the misconceptions about the transmission or acquiring AIDS?

How did Louis Pasteur successfully demolish the popular theory of spontaneous generation? What were his conclusions?

Differentiate between in situ and ex situ approaches of conserving biodiversity.

The image below describes the process of Gene Therapy.

i. What is gene therapy?
ii. Name the first clinical case in which it was used.

i. Explain how to find whether an E.coli bacterium has transformed or not when a recombinant DNA bearing ampicillin resistant gene is transferred into it.
ii. What does the ampicillin resistant gene act as in the above case?

A single base mutation in a gene may not 'always' result in loss or gain of function. Do you think the statement is correct? Defend your answer.

Draw a labelled sketch of L.S. of pistil showing the progamous type of fertilization.

i. Why must a cell be made 'competent' in biotechnology experiments? How does calcium ion help in doing so?
ii. State the role of 'biolistic gun' in biotechnology experiments.

Which property of DNA double helix led Watson and Crick to hypothesise semi-conservative mode of DNA replication? Explain.

Assertion (A): Homo sapiens have evolved from chimpanzee-like ancestors.
Reason (R): There is no difference between the two in the amino acid sequence of the protein Cytochrome-C.

Assertion (A): Vertical distribution of different species occupying different levels in the ecosystem is called stratification.
Reason (R): Trees occupy top vertical strata or layer of a forest, herbs, grasses the second and shrubs occupy the bottom layers.

Assertion (A): The primary effluent is passed into large aeration tanks where it is constantly agitated mechanically and the air is pumped into it.
Reason (R): This allows vigorous growth of useful anaerobic microbes into flocs.

Assertion (A): Reproductive health means total well-being in all aspects of reproduction, i.e., physical, emotional, behavioural, and social.
Reason (R): A society with people having physically and functionally normal reproductive organs might be called reproductively healthy.

Read the following text carefully and answer the questions that follow:
Cancer refers to any one of a large number of diseases characterized by the development of abnormal cells that divide uncontrollably and have the ability to infiltrate and destroy normal body tissue. Cancer often has the ability to spread throughout your body. Cancer is the second-leading cause of death in the world.

i. How does a cancerous cell differ from a normal cell? (1)
ii. Benign tumor is less dangerous than malignant tumor. Why? (1)
iii. Describe causes of cancer. (2)
OR
Mention two methods of treatment of the disease. (2)

Read the following text carefully and answer the questions that follow:
The reproductive cycle in female primates (e.g. monkeys, apes and human beings) is called the menstrual cycle. In human females, menstruation is repeated at an average interval of about 28/29 days, and the cycle of events starting from one menstruation till the next one is called the menstrual cycle Anita has show Diagrammatic presentation of various events during a menstrual cycle.

i. What role do pituitary gonadotropins play during the follicular and ovulatory phases of the menstrual cycle? (1)
ii. The first half of the menstrual cycle is called the proliferative phase as well as the follicular phase. Give reason.(2)
iii. Why does corpus luteum stay active throughout pregnancy and in the absence of fertilization, is active only for 10-12 days?
OR
What happens to corpus luteum in human female if the ovum is (2)
a. fertilised,
b. not fertilised?