Q25
3 marksShort AnswerSection B

Write the full form of DNA. Name the part of the cell where it is located. Explain its role in the process of reproduction of the cell.

How do Organisms Reproduce?
DNA and its Role in Reproduction
Official Answer
  1. Full Form of DNA: Deoxyribo Nucleic Acid.
  2. Location in the Cell: DNA is located in the chromosomes within the nucleus of a cell.
  3. Role of DNA in Cell Reproduction:
  • Information Source: DNA is the primary source of information for making proteins. If this information is altered, different proteins will be made, leading to altered body designs.
  • DNA Copying: A basic event in reproduction is the creation of a DNA copy using chemical reactions. This ensures that genetic features are inherited from parents to the next generation.
  • Cellular Apparatus Creation: DNA copying is accompanied by the creation of an additional cellular apparatus. This is essential because a DNA copy pushed out without an organized cellular structure cannot survive or maintain life processes.
Deoxyribo Nucleic AcidNucleusChromosomesInformation sourceProteinsDNA copyingCellular apparatus

Marking Scheme

  • 1State the full form of DNA as Deoxyribo Nucleic Acid (1 mark)
  • 2State the location of DNA (chromosomes in the nucleus) (1 mark)
  • 3Explain the role of DNA copying and protein synthesis in cell reproduction (1 mark)

Hint

Think about where chromosomes are found in a cell and what DNA stands for. Remember that DNA contains the blueprints for making proteins.

Quick Oral Answer

DNA stands for Deoxyribo Nucleic Acid. It is located in the chromosomes inside the cell nucleus. Its role is to act as the blueprint for making proteins and to transmit genetic information to the next generation through DNA copying.

Analysis & Explanation

According to the NCERT textbook, chromosomes in the nucleus contain genetic information in the form of DNA molecules. During cell division, the cell must make two copies of its DNA. However, simply copying the DNA is not enough; the cell must also duplicate its cellular machinery (cytoplasm, organelles) so that both resulting daughter cells are fully functional and capable of sustaining life. Variations occur during this copying process because no biochemical reaction is 100% accurate, which serves as the basis for organic evolution.

Common Mistakes

  1. 1Writing incorrect spellings for 'Deoxyribo Nucleic Acid'.
  2. 2Stating that DNA is located generally in the cytoplasm instead of specifically in the nucleus/chromosomes.
  3. 3Failing to mention that DNA copying must be accompanied by the creation of an additional cellular apparatus for the cell to survive.

Interesting Facts

No biochemical reaction is absolutely reliable. Therefore, every time DNA copies, minor variations are introduced, which is the fundamental driver of evolution!

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Frequently Asked Questions

How many marks does this question carry in CBSE Class 10 Science 2010?

This question carries 3 marks in the CBSE Class 10 Science 2010 examination.

Which chapter does this question come from in Science?

This question is from the chapter "How do Organisms Reproduce?" in the CBSE Class 10 Science syllabus.

What topic does this question cover in Science?

This question covers the topic "DNA and its Role in Reproduction" from CBSE Class 10 Science.

What type of question is this in the CBSE Class 10 Science 2010 paper?

This is a Short Answer question from Section B in the CBSE Class 10 Science 2010 paper.