[Mission 2023] STATIC QUIZ, 31 October 2022 – Environment

Solution: d)

Magnesium forms a part of the chlorophyll molecule – essential in photosynthesis.

Iron is taken up in ferrous and ferric forms by plants. It acts as a catalyst in the production of chlorophyll.

Cu+2 (copper) can be absorbed through leaves. It becomes very toxic if too much applied. It is also a catalyst in chlorophyll formation.

Solution: a)

Photoperiodism is the physiological reaction of organisms to the length of day or night. It occurs in plants and animals.

It has been observed that some plants require a periodic exposure to light to induce flowering. It is also seen that such plants are able to measure the duration of exposure to light.

For example, some plants require the exposure to light for a period exceeding a well defined critical duration, while others must be exposed to light for a period less than this critical duration before the flowering is initiated in them.

Together with temperature changes, photoperiod provokes changes in the colour of fur and feathers, migration, entry into hibernation, sexual behaviour etc. For e.g. the singing frequency of birds such as the canary depends on the photoperiod.

Solution: a)

The organisms (both flora and fauna) in the aquatic ecosystem are unevenly distributed but can be classified on the basis of their life form or location into five groups

1. i) Neuston:

• These are unattached organisms which live at the air water interface such as floating plants, etc.

1. ii) Periphyton:

• These are organisms which remain attached to stems and leaves of rooted plants or substances emerging above the bottom mud such as sessile algae and their associated group of animals.

iii) Plankton:

• This group includes both microscopic plants like algae (phytoplankton) and animals like crustaceans and protozoans (zooplankton) found in all aquatic ecosystems, except certain swift moving waters.

1. iv) Nekton:

• This group contains animals which are swimmers.
• The nektons are relatively large and powerful as they have to overcome the water currents.
• The animal’s range in size from the swimming insects (about 2 mm long) to the largest animals, the blue whale.

1. v) Benthos:

• The benthic organisms are those found living in the bottom of the water mass.
• Practically every aquatic ecosystem contains well developed benthos.

Solution: b)

Seaweeds are (thalloid plants) macroscopic algae, which mean they have no differentiation of true tissues such as roots, stems and leaves. They have leaflike appendages.

Seaweeds, the larger and visible marine plants are found attached to rocks, corals and other submerged strata in the intertidal and shallow sub tidal zones of the sea.

Seaweeds grow in shallow coastal waters wherever sizable substrata is available.

Based on the colour of their pigmentation, sea weeds are broadly classified into different classes such as blue-green, green, brown, red, etc.

Seaweeds are important as food for humans, feed for animals, and fertilizer for plants.

Seaweeds are also used as the potential indicators of pollution in coastal ecosystem, particularly heavy metal pollution due to their ability to bind and accumulate metals strongly.

Solution: c)

Carnivorous plants are plants that derive some or most of their nutrients from trapping and consuming animals or protozoans, typically insects and other arthropods. However, carnivorous plants generate energy from photosynthesis. Carnivorous plants have adapted to grow in places where the soil is thin or poor in nutrients, especially nitrogen, such as acidic bogs.