Biology Question Paper 2080 (Old Question)

The crossing over is the interchange of chromatid segments between the two homologous chromosomes. Which of the following is the most likely explanation for high incidence of crossing over between two genes?

What are called the two nuclei present at the end of the pollen tube?

Which of the following cells has cytoplasm but no nucleus in mature stage?

Two cells A and B are contiguous as shown in the diagram. Cell A has osmotic pressure 12 atm, turgor pressure 9 atm, and diffusion pressure deficit 5 atm. Cell B has osmotic pressure 10 atm, turgor pressure 5 atm, and diffusion pressure deficit 7 atm. Which one of the following results will happen?

Which of the following is not a part of methods of hybridisation?

Collenchyma and sclerenchyma are two types of simple permanent tissues of plants. Draw a labelled diagram of each. Distinguish them on the basis of structure and function.

Explain briefly about the double helix structure of DNA with necessary diagram.

What is ascent of sap? Describe how transpiration pull, cohesive and adhesive properties cause ascent of sap in tall trees.

Draw a longitudinal section of a pistil showing pollen germination. Explain the events on the embryo-sac during the process of fertilization.

“DNA recombinant technology is our friend as well as foes”, comment upon this statement with reasons.

How do chromosomal mutations affect organisms? Elucidate the types of chromosomal mutation. Why do mutations play significant roles in agriculture and in evolution?

Geneticists have found that not all traits show simple dominant-recessive relationship. Justify this statement by describing incomplete dominance and codominance with suitable illustrations

Describe the process which occurs during the photosystem-I and photosystem-II of the light reaction of photosynthesis, up to the formation of NADPH₂. Why is this process referred to as non-cyclic? How is it linked to the dark reaction?

Haversian system is the diagnostic feature of bones. Which of the following animal has this system present?

During tissue respiration, CO₂ formed in the tissues is highly toxic to the body. How would the blood expel CO₂ from tissues to the lungs?

Which part of human body the organ of Corti is present?

Which structure is found in the blastula stage?

A person is suffering from respiratory disorder. What would be the possible cause of COPD?

How would you detect a baby to be born having genetic defect? Name the technique.

Draw a labelled diagram of a neuron. How would you differentiate medullated and non-medullated neuron?

Describe the process of spermatogenesis in animals with diagram.

Define health disorders. Explain various cardio-vascular disorders in human beings.

Study the given diagram of L.S. of Adrenal gland and answer the following questions.

How would you elaborate the phenomenon of ultra-filtration in process of urine formation in human body?

Discuss the causative agent, mode of transmission and symptoms of Typhoid. Mention its control measures.

Human heart is myogenic. Justify this statement. Discuss origin and conduction of heart beat. How is heart beat regulated?

How would you explain various protective layers of human brain? What do you predict in the body when cerebro-spinal fluid is absent? Compare cerebrum and cerebellum.