Ecosystems and Energy Flow — BIOLOGY STD 12 Science — Question

Read the following and answer any four questions from (i) to (v) given below:
When it comes to biopesticides, one of the most widely used fungi is Beauveria bassiana. It infects a range of insects like, pecan weevil, Colorado potato beetle, kudzu bug, etc. It causes a disease known as the white muscardine. Even after an insect is killed, the white mold continues to produce millions of new infective spores that are released into the environment. It is commercially formulated as products including Naturalis L, Mycotrol, BotaniGard, etc. Some other widely used molds are Trichoderma, Metarhizium, etc. Some of them release enzymes that dissolve potential pathogens, others form barriers around plant roots and make it impossible for harmful bacteria and pathogens to pass through.

1. The key benefits of the biopesticides are that they are:

1. Highly effective.
2. Target specific.
3. Reduced environmental risks.
4. all of these.

2. Naturalis-L is a conunercial formulation containing:

1. Bacterial biopesticide.
2. Fungal biopesticide.
3. Fungal biofertiliser.
4. Chemical pesticide.

3. Which of the following is used as an effective bacterial biopesticide?

1. Trichoderma.
2. Beauveria.
3. Bacillus thuringiensis.
4. All of these.

4. Baeuveria causes a disease called:

1. White muscardine.
2. Aspergillosis
3. Green muscardine.
4. Powdary mildews.

5. Assertion: Trichoderma, found in root ecosystem, exerts biological control over several plant pathogens.

Reason: Trichoderma release enzyme which inhibits growth of several disease causing pathogens.

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:
A typical angiospermic ovule is a small structure attached to the placenta by means of a stalk called funicle. The body of the ovule fuses with funicle in the region called hilum. Each ovule has one or two protective envelopes called integuments. Integuments encircle the nucellus except at the tip where a small opening called the micropyle is formed. Mature ovules are classified on the basis of funiculus. It can be orthotropous, anadromous, hernitropous, campylotropous, etc.

1. The body of the ovule consists of a mass of parenchymatous cells called:

1. Integuments.
2. Nucellus.
3. Hilum.
4. Funiculus.

2. Refer to the given figure and select the correct statement regarding it.

1. This type of ovule is found in cactus.
2. The micropyle comes to lie close to the funiculus due to unilateral growth of ovule.
3. It is most common type of ovule found in the members of Chenopodiaceae.
4. It is half inverted ovule.

3. Identify the parts labelled as A, B, C and D in the given figure and select the correct option.

S. No	A	B	C	D
(a)	Chalaza	Female gametophyte	Embryo sac	Micropyle
(b)	Chalaza	NuceIIus	Embryo sac	Micropyle
(c)	Micropyle	Egg	Embryo sac	Chalaza
(d)	Micropyle	Nucellus	Embryo sac	Chalaza

4. Mature ovules are classified on the basis of funiculus. If micropyle lie close to the funiculus, the ovule is termed as:

1. Orthotropous.
2. Anatropous.
3. Hemitropous.
4. Campylotropous.

5. In Asphodel us, ovule is:

1. Unitegmic.
2. Tritegmic.
3. Bitegmic.
4. Ategmic.

Distinguish between : Lymphocytes and Monocytes.

A regulatory body working under MoEF for the release of transgenic crop is ____________:

1. NBPGR
2. NSC
3. NIPGR
4. GEAC

Distinguish Between: Homozygous and Heterozygous.

Distinguish between : Vital Capacity of Lung and Total Lung Capacity.

Distinguish between : Ascariasis and Filariasis.

Read the following and answer any four questions from (i) to (v) given below:
A desert lizard (an ectotherm) and a mouse (an endotherm) are placed inside a chamber at 15ºC and their body temperature [T(L) for the lizard and T(M) for the mouse] and metabolic rates [M(L) for lizard and M(M) for the mouse] are monitored.

1. Which of the following is correct regardingT(L), M(L), T(M) and M(M)?

1. T(L) and M(L) will fall while T(M) and M(M) will increase.
2. T(L) and M(L) will increase while T(M) and M(M) will fall.
3. T(L) and M(L) will fall, T(M) will remain same and M(M) will increase.
4. T(L) and M(L) will remain same, T(M) and M(M) will decrease.

2. It can be said that some animals in their evolutionary development preferred to be ectotherms than endotherms. Which of the following can be the best suited reason for it?

1. The metabolic reactions of these organisms can occur at a very wide range of temperature.
2. Maintaining homeostasis is an energetically expensive process.
3. The enzymes of these organisms are functional at high temperatures.
4. Both (b) and (c).

3. Organisms that can maintain a constant internal temperature are called.

1. Homoeothermic
2. Poikilothermic
3. Oligothennic
4. Heterothennic

4. An animal that survives at temperature of 10ºC and 40ºC both can be placed under the category of:

1. Ectotherm.
2. Endotherm.
3. Modifiers.
4. Migratory organisms.

5. Study the graph carefully and select the correct option.

1. X could be desert lizard.
2. Y could be mouse.
3. Z could be desert lizard.
4. Both (a) and (b).