NCERT Solutions for Class 9 Biology: Diversity in Living Organisms

Class 9 is the first stepping stone for a student in the competitive world. With the introduction of the CBSE Board Exam for class 10 a few years back, this has become an important gateway for a student. Based on the results of class 9th a student selects his future stream of Science, Commerce or Arts suiting his interest.

Takshila Learning is providing NCERT Solutions for Class 9 Biology as per the latest syllabus by CBSE. Class 9 is the building block for the CBSE Class 10 Board Exams, not only for your exams but also for your higher studies and career. Biology is the most essential subject and the knowledge in this field opens up wider career opportunities for the students.

Below you can find the NCERT solution for Class 9th Biology. You can get a Solution for the all-important question of “Matter in our Surroundings“

Q1. Why do we classify organisms?

Ans:

By classifying organisms, studying their characteristics is easier and more convenient. The similarities exhibited by different entities allow us to classify different entities into one class and therefore study the group as a whole.

Q2. Give three examples of the range of variations that you see in life-forms around you.

Ans:

Listed below are a few ranges of variations observed in life-forms:

(a) Small frog to big whale

(b) Creeper to the eucalyptus tree

(c) Black cuckoo to colourful peacock.

Exercise-7.1 Questions with Answer

Q3. Which do you think is a more basic characteristic for classifying organisms?

(a) the place where they live.

(b) the kind of cells they are made of. why?

Ans:

The most basic classification of organisms must be established on the types of cells they are made of. The reason for this is that habitats may have species inhabiting harmoniously with different characteristics, whereas entities with similar cell arrangements will exhibit similar characteristics.

Q4. What is the primary characteristic on which the broad division of organisms is made?

Ans:

The basic feature on which organisms are mainly divided is the nature of cells. It is broadly classified as prokaryotic cells and eukaryotic cells followed by subclasses.

Q5. On what basis are plants and animals put into different categories?

Ans:

The following is the basis of the classification of plants and animals:(A) The most fundamental consideration of classification is the presence and absence of the cell wall.(b) The next important criterion is the method of nutrition. The mechanism through which entities acquire their nutrients is used as a basis for classification.

Exercise-7.2 Questions with Answer

Q6. Which organisms are called primitive and how are they different from the so-called advanced organisms?

Ans:

Primitive organisms exhibit a very simple and basic cell arrangement, mechanism and structure and no division of labor is observed. Advanced organisms, on the other hand, are millions of organisms, which are classified into different organs, with different functionality such as mammals.

Q7. Will advanced organisms be the same as complex organisms? Why?

Ans:

Yes. Complex organisms are similar to advanced organisms. The result of advancement leads to multiple cell arrangements that are uniquely driven.

Exercise-7.3 Questions with Answer

Q8. What is the criterion for classification of organisms as belonging to kingdom Monera or Protista?

Ans:

One of the most important differences in classification is the development of nuclei. Those that have no nuclear membrane are defined as monera, while those that have well-defined nucleus walls are protists.

Q9. In which kingdom will you place an organism which is single-celled, eukaryotic and photosynthetic?

Ans:

Since the cell is photosynthetic, it must have a well-defined nucleus wall. Therefore it needs to be placed in Protista kingdom.

Q10. In the hierarchy of classification, which grouping will have the smallest number of organisms with maximum common characteristics and which will have the largest number of organisms?

Ans:

(A) The organisms belonging to Kingdom Monera will have the smallest number of organisms and with maximum characteristics in common.(b) The largest number of organisms related to Kingdom Anemia will be of organisms.

Exercise-7.4 Questions with Answer

Q11. Which division among plants has the simplest organisms?

Ans:

Algae or Thallophyta has the simplest organisms among the plants.

Q12. How are pteridophytes different from the phanerogams?

Ans:

The following are the differences:

Q13. How do gymnosperms and angiosperms differ from each other?

Ans:

In gymnosperms, the seeds are naked while in angiosperms the seeds are covered.

 Exercise-7.5  Questions with Answer

Q14. How do poriferan animals differ from coelenterate animals?

Ans:

Listed below are the differences:

Q15. How do annelid animals differ from arthropods?

Ans:

Listed below are the differences:

Q16. What are the differences between amphibians and reptiles?

Ans:

Listed below are the differences:

Q17. What are the differences between animals belonging to the Aves group and those in the mammalian group?

Ans:

Listed below are the differences:

Exercise

Q1. What are the advantages of classifying organisms?

Ans:

Listed below are the advantages of classification of organisms:• When organisms are classified, their general characteristics can be easily studied.• The study of scientific experiments is simple.• Interpretation of humans with other entities can be explained. Their dependencies and interactions can be studied.• When the entities are genetically crossbred and modified, it paves the way for commercial applications.

Q2. How would you choose between two characteristics to be used for developing a hierarchy in classification?

Ans:

The basis of the beginning of the hierarchy will be formed by the gross character, while the basis for further steps will be taken care of by the fine character.for example:• Humans are classified under vertebrates because they are near the vertebral column.For classification of tetrapods,• For tetrapods, the existence of four organs is taken into consideration.• In the case of mammals, the mammary gland is the essential part.

Q3. Explain the basis for grouping organisms into five kingdoms.

Ans:

The following factors rule on the basis of group of organisms in five states,• The number of cells present forms the first criterion.• Further arrangement and number of layers exist.• Another important factor for classification is the existence of the cell wall• The classification of complex organisms is also based on the mode of nutritional intake.• To classify, we also consider the level of organization.

Q4. What are the major divisions in the Plantae? What is the basis of these divisions?

Ans:

The following table depicts plant division and the basis of classification for each division.

Q5. How are the criteria for deciding divisions in plants different from the criteria for deciding the subgroups among animals?

Ans:

• One of the major specialties for classifying plants into thalophytes and bryophytes is basic cell structure.• Gymnosperms and angiosperms are classified based on seed visibility.Therefore, morphological features play an important role in plant classification. In animal taxonomy, cytology is considered mainly because more minute structural changes are taken into account.• The presence and absence of various attributes decides the classification of higher hierarchies.

Q6. Explain how animals in Vertebrata are classified into further subgroups.

Ans:

Vertebrata has two subclasses

• Pisces
• tetrapod

In which, organisms belonging to the Pisces subclass have a streamlined body with tails and wings that help them in their movement (swimming), while the Tetrapoda species have four limbs of their movement.

In addition, tetrapod animals are classified as follows:

1. Amphibians: The animals belonging to this group are friendly in nature. They live on land as well as in water. They show the presence of special organs that allow them to breathe under water.

2. Reptilia: Animals belonging to this class crawl. Their skin is very thick and withstands extreme temperatures.3. Eaves: The cells of these organisms are modified which help in their flight. They lack teeth and instead have a beak and wings that cover their bodies.4. Mammals: Nutritional skills are seen in animals belonging to this group, as they have mammary glands to support them. Their skin is covered with hair and most of them are viperiporous in nature.