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Explore Class 12 Biology past and model questions by chapter, year, marks and question type.
178 questions found
Which of the following statement is more appropriate for early an amniocentesis test?
It takes place between 15 and 20 weeks of pregnancy
It may cause fetal injury and lethality
It helps to detect fetal complications
It may cause infertility.
After the release of mature ovum from the ovary, the Graffian follicle changes into corpus luteum which is the source of female sex hormones. In the woman, what would be the condition of corpus luteum in absence of pregnancy?
Secretes FSH and LH continuously
Secretes oxytocin and relaxin
Automatically degenerates after sometime
Remains intact and active
The parasympathetic nervous system releases a hormone acetylcholine. Which one of the following is activated by this hormone?
Regulate the involuntary response
Decrease the rate of heart beat
Increase blood pressure
Increase myocardial contractility.
How are the Glycolysis and Krebs (TCA) cycles linked? Draw a detailed flow chart of the Krebs cycle?
In Drosophila, an eye colour is X-linked. Explain. If white eye female Drosophila is crossed to red-eye male Drosophila, what result do you expect? Analyse briefly with the help of crosses.
What are plant growth hormones? Write the physiological functions of auxin. Mention its shortcoming of hyper use in crops.
What is genetic material? Describe the structure and functions of RNA. (1+2+1=4) Ans: The substance which stores biological information in a coded form, transfers it to the next generation and cause its expression in the offspring is called genetic material.
“Micropropagation is an analytical and conventional bulk breeding technique for rapid cloning of desirable stock”. Justify the statement by describing it briefly with the various stages of the micropropagation technique in plants.
Write the salient features of a monocot embryo in reference to its development pattern with diagrams
Some of the $C_4$ plants possess diagnostic features of Kranz anatomy. Select which of the following plant contains such features?
Wheat
Maize
Barley
Oats
On oxidation of glucose in the cells, $CO_2$ is released as a by-product. This CO2 is carried to the lungs for elimination. Explain how the transport of take place in human body? What is the role of carbonic anhydrase enzyme? Mention the significance of diaphragm in breathing?
Why typhoid is called enteric fever? Illustrate its causative agent, mode of transmission, symptoms and preventive measures.
Peer pressure plays a negative role in provoking smoking habits in adolescents. As a school captain, plan any two activities you would like to organize with the help of senior students and any other two activities you would like your school authorities to organize for the students to tackle this problem.
Mention any two hormones secreted by it.
Where is it located?
Identify the gland.
What is immunity? Explain its type.
Vas deferens transport spermatozoa from cauda epididymis to ejaculatory duct. What happens when the vas deferens of a male is surgically disconnected?
Sperms become non-motile
Sperms lack nuclei
Seminal fluid is without sperms
No spermatogenesis occurs
If the cerebellum of a person gets injured, it will have effect on which of the following physiological function?
Respiratory ability
Body movement
Memory function
Smelling power
Which one of the following sets contains the bacterial disease only?
Hepatitis, influenza, cholera
Cholera, typhoid, candidiasis
Tuberculosis, typhoid, cholera
Tuberculosis, cholera, candidiasis