Important Questions Test: The Living Organisms - Characteristics & Habitats - UPSC

In ecology, a habitat is the type of natural environment in which a particular species of organism lives. It is characterized by both physical and biological features. A species' habitat is those places where it can find food, shelter, protection and mates for reproduction.

The physical factors are for example soil, moisture, range of temperature, and light intensity as well as biotic factors such as the availability of food and the presence or absence of predators. Every organism has certain habitat needs for the conditions in which it will thrive, but some are tolerant of wide variations while others are very specific in their requirements. A habitat is not necessarily a geographical area, it can be the interior of a stem, a rotten log, a rock or a clump of moss, and for a parasitic organism it is the body of its host, part of the host's body such as the digestive tract, or a single cell within the host's body.

Leaves lose water by the process of transpiration but cactus grows in deserts and cannot afford to lose water. The spines of the cactus store water. They reduce air flow around cactus and help the plant to get enough water by storing it.

Hydrophytes are aquatic plants that are especially suited for living in aquatic environments. In order to survive, a hydrophyte, also known as an aquatic macrophyte, must either be completely submerged in water, or in some cases be allowed to float on the surface of the water. Example: Lotus, Sea weeds, Pistia, Water lily, Singhara etc.

Global warming occurs when carbon dioxide (CO₂) and other air pollutants and greenhouse gases collect in the atmosphere and absorb sunlight and solar radiation that have bounced off the earth’s surface.

Biology is the science of life. Its name is derived from the Greek words "bios" (life) and "logos" (study). Biologists study the structure, function, growth, origin, evolution and distribution of living organisms.

A decomposer is an organism that decomposes, or breaks down, organic material such as the remains of dead organisms. Decomposers include bacteria and fungi. These organisms carry out the process of decomposition, which all living organisms undergo after death. Decomposition is an important process because it allows organic material to be recycled in an ecosystem.

Chlamydomonas is a genus of unicellular green algae (Chlorophyta). These algae are found all over the world, in soil, fresh water, oceans, and even in snow on mountain tops.

Around 11 % of the angiosperm plants produce latex. Latex is a milky product that is released from the shoot of the plants. It is usually a waste product of metabolism of plants which comes out of the stem.

It is a complex product containing resins, gums, tannins, starch, etc. On exposure to air after exudation, these products coagulate. As a result, the milky form is produced. It is useful for making glue, rubber, gum, lubricant, etc.

Growth in living things is Permanent and irreversible
- Living things undergo growth throughout their life cycle, which is a continuous process of increasing in size and complexity.
- Growth in living things is permanent, meaning that once an organism has reached its mature size, it does not continue to grow larger.
- This is true for most organisms, including plants, animals, and humans. Once they have reached their adult size, they do not continue to grow taller or larger.
- However, growth can still occur in other ways, such as the growth and repair of tissues, the development of new cells, and the increase in body mass through the accumulation of fat or muscle.
- Growth in living things is also irreversible, meaning that once an organism has completed its growth and development, it cannot go back to a previous stage.
- For example, a caterpillar undergoes growth and development to become a butterfly. Once it has transformed into a butterfly, it cannot revert back to being a caterpillar.
- Similarly, a seed grows into a plant through germination and development. Once the plant has reached maturity, it cannot revert back to being a seed.
- Therefore, growth in living things is both permanent and irreversible, as organisms continue to grow and develop until they reach maturity, and cannot reverse this process once it is complete.

Respiration is right answer as it break down simpler molecule of food to make CO₂ in humans and O₂ in plants.

The pores through which leaves exchange gases is Stomata. They are the small openings present on the inner surface of the leaves.

The cell (from Latin cella, meaning "small room") is the basic structural, functional, and biological unit of all known organisms. A cell is the smallest unit of life. Cells are often called the "building blocks of life". The study of cells is called cell biology, cellular biology, or cytology.

Plants which grow below the water surface and not in contact with atmosphere are called free floating submerged hydrophytes. E.g. Ceratophyllum, Hydrilla and Utricularia.

Biotic components, or biotic factors, can be described as any living component that affects another organism or shapes the ecosystem. This includes both animals that consume other organisms within their ecosystem, and the organism that is being consumed.

A heterotroph is an organism that cannot manufacture its own food by carbon fixation and therefore derives its intake of nutrition from other sources of organic carbon, mainly plant or animal matter. In the food chain heterotrophs are secondary and tertiary consumers.

Stimulus influences or causes a temporary increase of physiological activity or response in the whole organism or in any of its parts.

A unicellular organism is an organism that consists of a single cell. This means all life processes, such as reproduction, feeding, digestion, and excretion, occur in one cell. Amoebas, bacteria, and plankton are just some types of unicellular organisms. They are typically microscopic and cannot be seen with the naked eye.

Yeast is one of the few unicellular organisms that fall into the Kingdom Fungi.

The correct option is A.
Stages of Life: All life cycles start at birth, end with death, and involve growth and reproduction. Some living things go through their life cycle quickly, like male drone ants that live for only three weeks.
 

Wind helps to carry seeds far away from parent plant.seeds of some plants like Dandelion, Sycamore, Cotton are very light, and these plants have wings and hair on their seeds.

The plants survive in shady locales, but then grow quickly once surrounding trees fall down to expose sunlight. The trunk is sturdy but flexible, supported by many long roots that will keep a coconut palm alive after tipping over or leaning.

Their body colour being black,absorb heat from Sunlight & hence to cool it, take to a nearest water body. 

It means movement of plant in response to light. When potted plant is kept in a cardboard box with a small slit. Plant shows movement towards the light to acquire energy. We can also say it positive phototropism because it shows moment towards sunlight .

Lime water is the common name for Ca(OH)₂. It is usually used for testing of carbon dioxide and sulphur dioxide as both the gases turns lime water milky. We exhale Carbon dioxide, hence the lime water turns milky.

Hot object is stimulus.

Whales and dolphins are mammals and breathe air into their lungs, just like we do. They cannot breathe underwater like fish can as they do not have gills. They breathe through nostrils, called a blowhole, located right on top of their heads.