NCERT Class 6 Science Chapter 2 Diversity in the Living World Important Extra Questions and Answers

Very Short Answer Type Questions

Question 1.
What are herbs?
Answer:
The small plants with soft tender, green, short stem are called herbs. Herbs hardly attain height more than 1.5 metres. Their stems are not woody and can be bent. A herb may or may not have branches, e.g., tomato, mint, paddy, etc.

Question 2.
With the help of diagrams, tabulate the differences between a shrub and a tree, based on the properties of the stem.
Answer:
Shrub:

1. More branches arise from of stem.
2. The stem is hard and thin.

Tree:

1. The branches arise from the stem.
2. The stem is hard, thick and woody.

Question 3.
Look carefully at the plants shown in Fig. and identify their type. Are they herbs, shrubs or trees? Are they similar in shape? Which category has the biggest plants and which has the smallest?

Answer:
Close look of these plants make it clear that these plants are not of the same type.
Plants (a) and (b) are small and have soft and thin stem. These are called herbs.
Plant (c) has many branches arising from the base and its stem is thin but hard. It is a shrub.
Plant (d) is tall. Its stem is thick and hard, it is a tree.

Question 4.
From the members of the various groups given below, find the odd one out.
(a) Coriander (dhania), mint (pudina), jamun, grass.
(b) Rose, mehndi, guava, morepankh.
Answer:
(a) Jamun (Jamun is a tree while others are herbs).
(b) Guava (Guava is a tree while others are shrubs).

Question 5.
You are shown three branches of a rose in Fig. (a), (b) and (c) (below). Which one will help you best to recognize the plant?

Rose: (a) A leafless branch,
(b) A branch with leaves, and
(c) A branch with leaves and flowers
(c) A branch with leaves and flowers.
Answer:
(c) A branch with leaves and flowers.

Question 6.
What are climbers and creepers? Give some examples.
Answer:
In some plants like grape vines, money plant, bean stalk, gourd plants, etc., the stem is so weak that it cannot hold it straight. They either stand up with some support or they just spread on the ground. The ones which climb up are called climbers. For example grape vines, money plant. The ones which spread on the ground are called creepers or runners. For example gourd plants.

Question 7.
Read the function of parts of a plant given below:
(a) fixes plant to the soil
(b) prepares starch
(c) takes part in reproduction
(d) supports branches and bears flowers
In the diagram given in Fig. write the names of the parts whose functions you have just read at the appropriate space.

Answer:

(a) Fixes plant to the soil – root.
(b) Prepares starch – leaf.
(c) Takes part in reproduction – flower.
(d) Supports branches and bears flowers – stem.

Question 8.
Why do animals move from one place to other?
Answer:
Animals move from one place to other:
(i) To obtain their food and shelter.
(ii) To protect themselves from enemies and unfavourable climate.

Question 9.
Name the organs of locomotion of:
(a) Man
(b) Bird
(c) Fish.
Answer:
(a) Man – Legs
(b) Bird – Wings
(c) Fish – Fins.

Question 10.
What is adaptation?
Answer:
The change in specific features or certain habits, which enables a plant or an animal to live in its surroundings is called adaptation.

 

Question 11.
What is habitat?
Answer:
The surrounding where organisms survive, flourish and reproduce is called a habitat.

Question 12.
What are aquatic habitats?
Answer:
Habitats of plants and animals that live in water are called aquatic habitat.

Question 13.
What are terrestrial habitats? Give examples.
Answer:
The plants and animals that live on land are said to live in terrestrial habitats. For example, forests, grasslands, deserts, coastal and mountain region.

Question 14.
What are biotic components?
Answer:
The living things such as plants and animals in a habitat are its biotic components.

Question 15.
Explain abiotic components.
Answer:
Various non-living things such as rocks, soil, air and water in a habitat constitute its abiotic components.

Question 16.
Classify the following habitats into terrestrial and aquatic types. Grassland, Pond, Ocean, Rice field (NCERT Exemplar)
Answer:
Terrestrial habitats-Grassland, Rice field
Aquatic habitats – Pond, Ocean

Question 17.
Write the adaptation in aquatic plants due to which
(a) Submerged leaves can bend in the flowing water.
(b) Leaves can float on the surface of water.
Answer:
(a) Leaves are narrow and ribbon like.
(b) Stems/stalks of leaves are long, hollow and light.

 

Question 18.
Mention one adaptation present in the following animals:
(a) In camels to keep their bodies away from the heat of sand.
(b) In frogs to enable them to swim.
(c) In dolphins and whales to breathe in air when they swim near the surface of water.
Answer:
(a) Long legs
(b) Webbed feet
(c) Blow holes

Question 19.
Some desert plants have very small leaves whereas some others have only spines. How does this benefit the plants?
Answer:
Some desert plants have very small leaves whereas some others have only spines. These are adaptations to dry conditions. As a result of these modifications the surface of lamina is reduced thereby reducing water loss by transpiration.

Question 20.
What are the specific features present in a deer that helps it to detect the presence of predators like lion?
Answer:
The specific features present in a deer that helps it to detect the presence of predators like lion are:
(a) Long ears to hear movement of predators.
(b) Eyes on the sides of its head which allow it to look in all directions.

Question 21.
What is biodiversity?
Answer:
Biodiversity refers to the variety of life forms on Earth, including all living organisms, their interactions and ecosystems.

Question 22.
Give one characteristic that differentiates dicots from monocots.
Answer:
Dicots have two cotyledons, while monocots have one cotyledon in their seed.

Question 23.
What is a taproot system?
Answer:
A taproot system has a central, thick root with smaller lateral roots branching out, typically found in dicots:

Short Answer Type Questions

Question 1.
Why is biodiversity important for ecosystem stability?
Answer:
Biodiversity is crucial for ecosystem stability because it ensures the provision of essential services like pollination, nutrient cycling and climate regulation and contributes to the overall health and balance of the environment.

Question 2.
How does students observe and record animal movements during the nature walk?
Answer:
Students observe the body parts used for movement, such as legs, wings, or fins and record how animals move, including whether they fly, swim, crawl, or walk.

Question 3.
What is the difference between reticulate and parallel leaf venation?
Answer:
Reticulate venation has a network of interconnected veins, typical in dicots, while parallel venation has veins running parallel to each other, typical in monocots.

Long Answer Type Questions

Question 1.
Describe the concept of biodiversity and explain its significance in maintaining ecological balance.
Answer:
Biodiversity refers to the variety and variability of life forms on Earth, encompassing the different species of plants, animals, fungi and microorganisms, as well as their interactions with each other and their environment.

Significance in ecological balance:
Ecosystem functions: Different species contribute to various ecological processes, such as nutrient cycling, which is the movement of nutrients through the environment and liying organisms. For example, decomposers like fungi and bacteria break down dead organic matter.

Ecosystem resilience: A diverse ecosystem can better absorb shocks because different species have different roles and functions. For instance, a forest with a variety of tree species is more likely to remain stable after a pest outbreak compared to a monoculture forest.

Ecological stability: Biodiversity contributes to the stability of ecosystems by ensuring a balance of species interactions. Predator-prey relationships, competition for resources and symbiotic relationships all contribute to the regulation of populations and the maintenance of ecological balance.

Human benefits: Biodiversity provides numerous benefits to humans, including resources for food, medicine and materials.

Adaptation and evolution: Biodiversity is a source of genetic variation that is essential for the adaptation and evolution of species.

Question 2.
Explain the role of grouping in understanding biodiversity and its impact on conservation efforts.
Answer:
Role of grouping in understanding biodiversity:
Simplification and organisation: Grouping organisms into categories such as species, genus, family and so on, simplifies the study of biodiversity.

Understanding evolutionary relationships: Grouping organisms based on shared characteristics and evolutionary history allows scientists to trace the development of species over time.

Identifying patterns and trends: Classification helps in identifying patterns in biodiversity, such as the distribution of species in different habitats and the occurrence of certain traits.

Prioritising conservation actions: Conservationists use classification to focus on endangered or threatened species, which can be prioritised for protection and recovery efforts. For example, if a particular family of birds is declining, conservation efforts can target this group to prevent its extinction.

Managing habitats and ecosystems: By understanding the needs of different species within a habitat, conservationists can implement measures to protect these environments and ensure the survival of diverse species.