List of top Biology Questions asked in ICSE Class XII

Name an artificial chromosome used as a vector for Penicillium notatum.
Given below are two statements marked Assertion and Reason.
Assertion: Individuals with Klinefelter syndrome lose their secondary sexual characters and develop gynaecomastia.
Reason: The presence of the XYY chromosomal pattern leads to underdeveloped testes and reduced testosterone levels in affected males.

Study the diagram given below and answer the questions that follow.


 

As a pait of his tescarch, Arun conducted a study on the number of locusts in a forest, He compiled his findings in the form of the following dala.


 

Study the chemical structure of an addictive drug shown below and answer the questions that follow.


 

A biologist surveyed islands of different sizes and consolidated the results in the form of the data given below. Study the data carefully and answer the questions that follow.


 

The diagram below shows DNA banding patterns obtained after DNA samples collected from a crime scene were subjected to gel electrophoresis. Samples from crime scene are denoted by C and three suspects are represented by Sı, S2, S3.

The two structures shown below are formed in the process of spermatogenesis. Study them carefully and answer the questions that follow.


 

Differentiate between oogenesis and spermatogenesis on the following basis:
(a) Number of products
(b) Gonadal hormones
Draw a flowchart to represent the process of oogenesis.
Role of pollen-pistil interaction in hybrid formation.
Outline three major steps in artificial hybridisation.
Plasmodium is a digenetic parasite, completing its life cycle in humans and mosquitoes. In humans, it completes different parts of its life cycle in the liver and RBCs.
Draw a flow chart to outline its erythrocytic cycle in, humans.
What is the fate of: (a) Apical cell? (b) Basal cell?
Which embryo (X or Y) is likely to develop into a normal dicot embryo?
If there are 16 chromosomes in somatic cells of a male honeybee, how many in spermatozoa?
Draw a flowchart for sex determination in honeybees.
Why is functional insulin produced by rDNA technology better than the ones produced earlier?
Name the company that produced genetically engineered insulin for the first time.
How is mature insulin different from pro-insulin secreted by pancreas in humans?
Predict the outcome of an experiment where a plasmid without a selectable marker was used as a vector.
Identify and explain the type of ecological interaction where Paramecium caudatum got eliminated when grown with Paramecium aurelia based on Gause’s principle.

Based on data (Birds decline, Plants % decline, Area decline), interpret two reasons for change in the population of migratory birds. 

 

Anthony needs to obtain biological products in large quantities. He has a vessel with a sparger and one with a stirrer. Which is more advantageous? Why?