Reproduction in Lower and Higher Plants — BIOLOGY STD 12 Science — Question

Read the following and answer any four questions from (i) to (v) given below:
ln many species of fig trees, there is a tight one-to-one relationship with the pollinator species of wasp. It means that a given fig species can be pollinated only by its 'partner' wasp species and no other species. The wasp pollinates the fig inflorescence while looking for suitable egg-laying sites. ln return for the favour of pollination, the fig offers the wasp some of its developing seeds as food for the developing wasp larvae.

1. The interaction between fig trees and wasp is an example of:

1. Mutualism
2. Commensalism
3. Amensalism
4. Parasitism

2. AD the given interactions are similar to interaction between fig trees and wasp, except.

1. Plant and animal relation for pollination.
2. Association of algae and fungi in lichens.
3. Association of cattle egret and grazing cattle.
4. Association of fungi and roots of higher plants in mycorrhiza.

3. In which of the following interactions both partners are adversely affected?

1. Parasitism
2. Mutualism
3. Competition
4. Predation

4. ln relationship between fig and wasp:

1. One benefitted other harmed.
2. Both are benefitted.
3. One benefitted other unaffected.
4. One inhibited, other unaffected.

5. Assertion: Fig and wasp cannot complete their life cycle without each other.

Reason: They show mutualistic relationship.

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 : Hypertension and Hypotension.

Read the following and answer any four questions from (i) to (v) given below:
Embryo develops at the micropylar end of the embryo sac, where the zygote is situated. Most zygotes divided only after certain amount of endosperm is formed. The early stages of embryo development are similar in both monocotyledons and dicotyledons. The zygote gives rise to the proembryo and subsequently to the globular heart-shaped and mature embryo. A typical dicotyledonous embryo consists of an embryonal axis and two cotyledons. Embryo of monocotyledons possess only one cotyledon.

1. True embryo develops as a result of fusion of:

1. Two polar nuclei of embryo sac.
2. An egg cell and a male gamete.
3. Synergid and male gamete.
4. A male gamete and antipodals.

2. Refer to the given diagram of the embryo of an angiospermous plant with parts labelled P, Q and R. Select the correct statement(s) regarding this.

1. Part 'P' supplies nutrition to the developing embryo.
2. Part 'Q' is the protective sheath of radicle and root cap.
3. Part 'R' is the protective sheath of shoot apex and leaf primordia.
4. The embryo shown in the diagram is present in members of Family Poaceae.

1. (IV) only.
2. (II) and (III) only.
3. (I) and (IV) only.
4. (I), (II), (III) and (IV).

3. Which of the given statements are true?

1. During the development of a dicot embryo, heart-shaped embryo is followed by globular embryo.
2. The part of embryonal axis above the level of cotyledons is epicotyl, while the part below the level of cotyledons is hypocotyl.
3. Monocot seeds possess a single cotyledon, represented by scutellum.

1. (I) and (II).
2. (II) and (III).
3. (I) and (III).
4. (I), (II) and (III).

4. Consider the following parts of an embryonal axis of a dicot seed.

1. Hypocotyl.
2. Epicotyl.
3. Radicle.
4. Plumule.

In which of the following the above parts are correctly arranged from top to base?

1. (III) → (I) → (II) → (IV).
2. (II) → (I) → (III) → (IV).
3. (IV) → (II) → (I) → (III).
4. (III) → (IV) → (II) → (I).

5. In grass family, the cotyledon, is called:

1. Epiblast.
2. Plumule.
3. Scutellum.
4. Perisperm.

A patient is suffering from ADA deficiency. Can he be cured? How?

Microorganisms include bacteria, viruses, fungi and protozoa. In our mind, we presume, most of the time, that microbes are always harmful. Microbes are, of course, the causal agents of many infections diseases of plants and animals including humans but they also have lots of beneficial role. Lactic acid bacteria (LAB) are one of this kind of useful group. These are Gram positive, non-sporulating, either rod-shaped or spherical bacteria. They produce lactic acid in milk products as major metabolic end product of carbohydrate fermentation. LAB are considered as natural fermentors. Lactobacillus is a common LAB which converts lactose sugar of milk into lactic acid, that causes coagulation and partial digestion of milk protein casein. Milk is then changed into curd, yoghurt and cheese. Lactobacillus is also used in probiotics which have potentially beneficial effect on gut ecosystem of humans. Some other probiotic strain used belong to the Genus Bifidobacterium.

1. Which of the following is not considered as microorganisms?

1. Bacteriophage.
2. Streptococcus.
3. Porphyra.
4. Staphylococcus.

2. Select the incorrect option regarding the characteristics of lactic acid bacteria.

1. They are rod-shaped or spherical.
2. They are Gram positive.
3. They take part in carbohydrate fermentation.
4. They are acid intolerant.

3. Which of the following is not a lactic acid producing bacteria?

1. Streptococcus.
2. Lactococcus.
3. Saccharomyces.
4. Enterococcus.

4. Probiotics are:

1. Gut friendly live bacteria.
2. Acid balancing alternated bacteria.
3. Beneficial amount of dead bacteria.
4. Gram negative attenuated bacteria.

5. Assertion: Lactobacillus bacteria do not retain crystal violet stain while staining.

Reason: Lactobacillus have a very thin layer of peptidoglycan layer in their cell wall.

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.

Read the following and answer any four questions from (i) to (v) given below:
Excessive exploitation of species, whether a plant or animal reduces the size of its population so it becomes vulnerable to extinction. Such as Dodo and passenger pigeon have become extinct due to over exploitation by humans. Thus the world is facing accelerated rates of species extinctions, largely due to human interference.

1. Which of the following cause of biodiversity loss is not included in evil quartet?

1. Coextinction.
2. Pollution.
3. Alien species invasion.
4. Habitat loss and fragmentation.

2. Identify the species that have become extinct due to over exploitation.

1. Stellar sea cow.
2. Yucca moth.
3. Blatta orientalis.
4. Nile Perch.

3. Factors which make species susceptible to extinction are:

1. Large population size.
2. Lack of genetic variability.
3. Ower status of trophic level.
4. Ability to switch over to ahem ate foods.

4. Assertion: Pollution reduces species biodiversity.

Reason: Spill over of oil in sea causes death of several marine animals.

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.

5. ________ is the first major cause of species extinction.

1. Coextinction.
2. Over exploitation.
3. Habitat destruction.
4. Alien species invasion.

Read the following and answer any four questions from (i) to (v) given below:
Disposal of untreated sewage into the river or freshwater pond causes huge water pollution. Four water samples from different sources (A, B, C, D) are collected and tested for BOD value in a lab to assess their quality. The BOD values are presented in the given table. Water samples are collected from primary effluent, secondary effluent, untreated sewage and river water. Study the given table and answer the following.

Sample	BOD
A	20mg/ L
B	5mg/ L
C	300mg/ L
D	400mg/ L

1. The source of sample 'C' is:

1. River water.
2. Primary effluent.
3. Secondary effluent.
4. Untreated sewage water.

2. If sewage in untreated condition is disposed off in a freshwater body then.

1. BOD and dissolved oxygen both will increase.
2. BOD will increase and dissolved oxygen will decreas.
3. BOD will decrease and dissolved oxygen will increase.
4. BOD and dissolved oxygen both will decrease.

3. A large number of pathogenic microbes can be present in water sample of:

1. C
2. A
3. D
4. Both (a) and (c).

4. High value of BOD in sample O is due to:

1. High amount of organic wastes and aerobic microbes.
2. High amount of inorganic wastes and anaerobic microbes.
3. High amount of organic wastes and anaerobic microbes.
4. High amount of inorganic wastes and aerobic microbes.

5. River water is represented by the sample.

1. A
2. B
3. C
4. D