Class 6 Science, Chapter 2 (NCERT). 15 questions by concept, 13 with pictures. Open “Show answer” for the answer and why.
How to teach this chapter · Common misconceptions & worked visual for this chapter
Use the grouping chart to decide what similarity or difference was used to make the two groups. What basis does the chart show?
(b) hard or soft stem
The chart puts items with the same feature tag together. The shared difference between the two columns is hard or soft stem. Grouping by a common feature helps us study similarities and differences.
Cow, cockroach, pigeon, bat, tortoise, whale, fish, grasshopper and lizard have to be put into two groups. The feature used must be different from height, flowers, stem, eating habits, place, colour and movement. Which response groups these animals by a common feature?
(d) Feature: presence or absence of wings. Group 1: cockroach, pigeon, bat, grasshopper. Group 2: cow, tortoise, whale, fish, lizard.
A good grouping picks one feature and uses it for every animal. Wings are a feature of the animals themselves, so presence or absence of wings sorts all nine of them. Liking an animal or its place in the list is not a feature of the animal. More than one grouping can be correct, but each grouping must be based on a shared feature.
Use the line drawing. What does the marked relationship show?
(b) Plants and animals are dependent on each other.
The marked relationship is one role in biodiversity. Trees can provide food or shelter to birds and other animals, and animals can help in spreading seeds after eating fruits. This shows that plants and animals are dependent on each other.
Which statement best describes biodiversity in a region?
(d) The variety of plants and animals found in that region
Biodiversity means the variety of plants and animals found in a particular region. It is not only animals, only plants, or only the organisms that someone happened to draw.
Two weak-stem plants are observed. Plant A creeps along the ground. Plant B needs support to climb and grow. Which pairing is correct?
(a) Plant A is a creeper and Plant B is a climber
Both plants have weak stems, but they grow differently. The plant that uses a support to climb upward is a climber, and the plant that spreads along the ground is a creeper.
A student looks at a plant with many hard brown woody stems. The plant is not as tall as a tree, and its branches start very close to the ground. The student's note says: "hard stem, so tree." What feature did the student miss?
(b) The plant is not as tall as a tree and its stems branch very close to the ground.
The note uses only the hard stem, but the rule also uses height and where branches start. A shrub can have hard brown woody stems, but it is not as tall as a tree and often branches close to the ground.
A weak-stem plant needs support to climb and grow. Which plant group is it?
(c) climber
The rule is about how the weak-stem plant grows. A plant that needs support to climb and grow is called a climber, while a plant that creeps along the ground is called a creeper. So this plant is a climber.
Plant 1 and Plant 2 have different root systems. In the drawing, one plant has one main root with small side roots. The other plant has many similar-sized thin roots from the base of the stem. Which comparison correctly describes the difference?
(d) Plant 1 has taproot system because it has one main root with small side roots. Plant 2 has fibrous roots because it has many similar-sized thin roots from the base of the stem.
A taproot system has one main root with small side roots. Fibrous roots appear as a bunch of similar-sized thin roots from the base of the stem. The two root systems are different because their root structures are different.
The drawing shows the lower stem and roots of a plant. The root system is marked with ?. What type of root system is drawn?
(b) taproot system
The drawing should be read by comparing the root structure. A root system with one main root with small side roots is taproot system. The important feature is the arrangement of the roots, not just that they are roots.
Use the flowchart to decide what can go at A and B. Here every plant with leaves has either reticulate or parallel venation. A plant reaches A when it has reticulate venation; it reaches B when it does not. Which pair fits A and B?
(a) A: plants with taproot; B: plants with fibrous roots
The flowchart sends plants with reticulate venation to A. Plants without reticulate venation go to B, and the linked leaf pattern used here is parallel venation. Reticulate venation is linked with dicot plants and taproot, while parallel venation is linked with monocot plants and fibrous roots.
A duck's feet are compared with the feet of another bird. Which observation correctly compares the feet?
(d) The duck has webbed feet.
The supplied comparison identifies the duck's feet as webbed feet. The difference to notice is about the feet, not about where the birds are seen or the fact that both are birds.
The marked part is on a duck's foot. Which label names this marked part?
(a) Webbed feet
The labelled part on the duck is its webbed feet. This is a body part used for movement, not a place where the bird is seen.
A student groups animals in a Venn diagram. The Aquatic-only part has Dolphin and Frog. The Terrestrial-only part has Sheep. The Both habitats part is empty. Frog can live in water as well as on land. What change is needed?
(d) Move Frog to the Both habitats part.
The grouping has put frog in only one part. Frog can live in water as well as on land. It should be placed in the both-habitats part.
In the Venn diagram, the left circle is labelled Aquatic and the right circle is labelled Terrestrial. What does the region marked ? mean?
(d) animals living in water as well as on land
A circle labelled Aquatic means animals that live in water. A circle labelled Terrestrial means animals that live on land. The marked region is animals living in water as well as on land.
A flow diagram shows a cause-effect chain ending in loss of biodiversity. What goes in the missing middle box?
(b) Plants and animals lose homes, food, and other resources.
The diagram begins with damage to habitats and ends with loss of biodiversity. The missing step is that plants and animals lose their homes, food, and other resources.
Wrong
A whale is a fish because it lives in water.
Why it feels right. The habitat seems like the easiest feature to use.
Right
Classify using traits such as breathing and feeding young.
Worked example
