Biotechnology — BIOLOGY STD 12 Science — Question

Read the following and answer any four questions from (i) to (v) given below:
Riya studies in 11 standard in a government school. She belongs to a backward family and her parents did not get her properly vaccinated according to immunisation programme. Once while playing in school playground she fell down due to weakness and developed high fever, headache and stiffness in her neck. identify the illness she could be suffering from and answer the following questions.

1. The microbe responsible for Riya's illness could be.

1. Vibrio cholerae
2. Enterovirus
3. Plasmodium
4. Mycobacteriurn.

2. Which vaccine, if administered earlier, would have saved Riya from the illness she unfortunately contracted?

1. Salk vaccine
2. MMR vaccine
3. BCG vaccine
4. Varicella vaccine

3. The disease that Riya has contracted spreads through.

1. Bite of an infected mosquito
2. Bite of an infected dog
3. Faecal oral route
4. Direct contact with the infected person.

4. Riya can spread her illness to other children through.

1. Her faeces
2. Direct contact
3. Coughing and sneezing in open
4. Vectors.

5. Assertion: Polio produces inflammation of the nervous system.

Reason : Stiffness of the neck, paralysis of particular skeletal muscle, is an important symptom of polio.

1. Both assertion and reason are true, and reason is the correct explanation of assertion.
2. Both assertion and reason are true, but reason is not the correct explanation of assertion.
3. Assertion is true, but reason is false.
4. Both assertion and reason are false.

Distinguish between: Spermatogenesis and Oogenesis.

Distinguish between : FSH and LH

Distinguish between: Blastula and Gastrula ### Give two differences between blastula and gastrula.

Distinguish Between: Phenotype and Genotype.

Eurythermal and stenothermal.

Read the following and answer any four questions from (i) to (v) given below: Unlike animals, plants cannot runaway for their defence, therefore, they have evolved an astonishing variety of morphological and chemical defences against herbivores. Thorns are the most common morphological means of defence. Many plants produce and store chemicals that make the herbivore sick when they are eaten, inhibit feeding or digestion, disrupt its reproduction or even kill it. Some plants produce highly poisonous chemicals and that is why no cattle or goats browse on those plants. A wide variety of chemical substances that we extract from plants on a conunercial scale are produced by them actually as defence against grazers and browsers.

1. Why you never see cattle or goats browsing on weed Calotropisl?

1. It produces highly poisonous tannins.
2. It produces quinine which is bitter in taste.
3. It produces poisonous cardiac glycosides.
4. It bears prickles.

2. What could be the possible reason for invasive growth of the prickly pear cactus introduced in Australia?

1. Absence of predators.
2. New mycorrhizal association.
3. Abundant water availability.
4. All of these.

3. Which of the following is most likely to sick by consuming chemicals produced by plants?

1. Frog
2. Goat
3. Human
4. Pigeon

4. Plant evolve variety of morphological and chemical defences against.

1. Prey
2. Predator
3. Commenal
4. Mutualist

5. Assertion: Some plant functions as predator in nature.

Reason: Phytoph ago us insects feed on plant sap.

1. Both assertion and reason are true and reason is the correct explanation of assertion.
2. Both assertion and reason are true but reason is not the correct explanation of assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.