Mitochondria and chloroplasts are similar as both are double-membraned organelles with their own DNA and ribosomes. They can synthesise some proteins independently. However, mitochondria perform cellular respiration and release energy, while chloroplasts carry out photosynthesis and produce food usiRead more
Mitochondria and chloroplasts are similar as both are double-membraned organelles with their own DNA and ribosomes. They can synthesise some proteins independently. However, mitochondria perform cellular respiration and release energy, while chloroplasts carry out photosynthesis and produce food using sunlight. Thus, they differ functionally but share structural similarities and evolutionary origin.
For more NCERT Solutions of Class 9 Science Exploration Chapter 2 Cell: The Building Block of Life (2026-27)
Renu is correct because plastids are present in all plant parts, including roots. While roots do not perform photosynthesis and lack chloroplasts, they contain leucoplasts, which store food materials like starch. Plastids are not limited to photosynthesis; they perform various functions. Therefore,Read more
Renu is correct because plastids are present in all plant parts, including roots. While roots do not perform photosynthesis and lack chloroplasts, they contain leucoplasts, which store food materials like starch. Plastids are not limited to photosynthesis; they perform various functions. Therefore, plastids are present in roots, supporting Renu’s statement
For more NCERT Solutions of Class 9 Science Exploration Chapter 2 Cell: The Building Block of Life (2026-27)
In pure water, Cell X gains water through osmosis and swells. In concentrated salt solution, Cell Y loses water and shrinks. This occurs because water moves across the cell membrane from higher to lower water concentration. The correct explanation is option (iii): water moves into Cell X and out ofRead more
In pure water, Cell X gains water through osmosis and swells. In concentrated salt solution, Cell Y loses water and shrinks. This occurs because water moves across the cell membrane from higher to lower water concentration. The correct explanation is option (iii): water moves into Cell X and out of Cell Y through the cell membrane.
For more NCERT Solutions of Class 9 Science Exploration Chapter 2 Cell: The Building Block of Life (2026-27)
Cell membrane is selectively permeable, controlling entry and exit of substances, while cell wall is freely permeable and provides support. Rough endoplasmic reticulum (RER) has ribosomes and appears rough, whereas smooth ER lacks ribosomes. Chloroplasts contain green chlorophyll for photosynthesis,Read more
Cell membrane is selectively permeable, controlling entry and exit of substances, while cell wall is freely permeable and provides support. Rough endoplasmic reticulum (RER) has ribosomes and appears rough, whereas smooth ER lacks ribosomes. Chloroplasts contain green chlorophyll for photosynthesis, while chromoplasts contain coloured pigments like red, yellow or orange for attraction.
For more NCERT Solutions of Class 9 Science Exploration Chapter 2 Cell: The Building Block of Life (2026-27)
Cells maintain balance by regulating growth through controlled cell division, contact inhibition and programmed cell death (PCD). Contact inhibition stops cells from dividing when they touch others. PCD removes unnecessary or damaged cells. Together, these processes ensure proper growth, prevent oveRead more
Cells maintain balance by regulating growth through controlled cell division, contact inhibition and programmed cell death (PCD). Contact inhibition stops cells from dividing when they touch others. PCD removes unnecessary or damaged cells. Together, these processes ensure proper growth, prevent overcrowding and maintain healthy functioning of tissues and organs.
For more NCERT Solutions of Class 9 Science Exploration Chapter 2 Cell: The Building Block of Life (2026-27)
Mitochondria and chloroplasts are two important organelles in a plant cell. Discuss how these two organelles are structurally and functionally similar to each other and different from each other.
Mitochondria and chloroplasts are similar as both are double-membraned organelles with their own DNA and ribosomes. They can synthesise some proteins independently. However, mitochondria perform cellular respiration and release energy, while chloroplasts carry out photosynthesis and produce food usiRead more
Mitochondria and chloroplasts are similar as both are double-membraned organelles with their own DNA and ribosomes. They can synthesise some proteins independently. However, mitochondria perform cellular respiration and release energy, while chloroplasts carry out photosynthesis and produce food using sunlight. Thus, they differ functionally but share structural similarities and evolutionary origin.
For more NCERT Solutions of Class 9 Science Exploration Chapter 2 Cell: The Building Block of Life (2026-27)
https://www.tiwariacademy.com/ncert-solutions/class-9/science/exploration-chapter-2/
See lessTwo students, Renu and Rohit, were having a discussion on the plastids. Renu emphasised that all parts of the plants, even roots, contain plastids. However, Rohit did not agree with the statement and told her that plastids are absent in plant roots since the roots are underground and do not need to perform photosynthesis. Who is correct? Justify your answer.
Renu is correct because plastids are present in all plant parts, including roots. While roots do not perform photosynthesis and lack chloroplasts, they contain leucoplasts, which store food materials like starch. Plastids are not limited to photosynthesis; they perform various functions. Therefore,Read more
Renu is correct because plastids are present in all plant parts, including roots. While roots do not perform photosynthesis and lack chloroplasts, they contain leucoplasts, which store food materials like starch. Plastids are not limited to photosynthesis; they perform various functions. Therefore, plastids are present in roots, supporting Renu’s statement
For more NCERT Solutions of Class 9 Science Exploration Chapter 2 Cell: The Building Block of Life (2026-27)
https://www.tiwariacademy.com/ncert-solutions/class-9/science/exploration-chapter-2/
See lessTwo similar animal cells are placed in two different solutions: Cell X is placed in pure water. Cell Y is placed in a concentrated salt solution. Cells are observed after some time. Cell X swells and Cell Y shrinks. Which statement provides the correct explanation for the above observations? (i) Salt molecules moved into Cell Y, causing it to shrink. (ii) Water moved into Cell X and more water moved out of Cell Y than the salt solution entered in it. (iii) Water moved into Cell X and moved out of Cell Y through the cell membrane. (iv) Solute movement caused osmosis in both cells.
In pure water, Cell X gains water through osmosis and swells. In concentrated salt solution, Cell Y loses water and shrinks. This occurs because water moves across the cell membrane from higher to lower water concentration. The correct explanation is option (iii): water moves into Cell X and out ofRead more
In pure water, Cell X gains water through osmosis and swells. In concentrated salt solution, Cell Y loses water and shrinks. This occurs because water moves across the cell membrane from higher to lower water concentration. The correct explanation is option (iii): water moves into Cell X and out of Cell Y through the cell membrane.
For more NCERT Solutions of Class 9 Science Exploration Chapter 2 Cell: The Building Block of Life (2026-27)
https://www.tiwariacademy.com/ncert-solutions/class-9/science/exploration-chapter-2/
See lessDifferentiate between the following pairs of terms based on the clues given in parentheses: (i) Cell membrane and cell wall (permeability) (ii) RER and SER (structure) (iii) Chloroplasts and chromoplasts (pigments)
Cell membrane is selectively permeable, controlling entry and exit of substances, while cell wall is freely permeable and provides support. Rough endoplasmic reticulum (RER) has ribosomes and appears rough, whereas smooth ER lacks ribosomes. Chloroplasts contain green chlorophyll for photosynthesis,Read more
Cell membrane is selectively permeable, controlling entry and exit of substances, while cell wall is freely permeable and provides support. Rough endoplasmic reticulum (RER) has ribosomes and appears rough, whereas smooth ER lacks ribosomes. Chloroplasts contain green chlorophyll for photosynthesis, while chromoplasts contain coloured pigments like red, yellow or orange for attraction.
For more NCERT Solutions of Class 9 Science Exploration Chapter 2 Cell: The Building Block of Life (2026-27)
https://www.tiwariacademy.com/ncert-solutions/class-9/science/exploration-chapter-2/
See lessHow do cells monitor their growth to maintain a balance?
Cells maintain balance by regulating growth through controlled cell division, contact inhibition and programmed cell death (PCD). Contact inhibition stops cells from dividing when they touch others. PCD removes unnecessary or damaged cells. Together, these processes ensure proper growth, prevent oveRead more
Cells maintain balance by regulating growth through controlled cell division, contact inhibition and programmed cell death (PCD). Contact inhibition stops cells from dividing when they touch others. PCD removes unnecessary or damaged cells. Together, these processes ensure proper growth, prevent overcrowding and maintain healthy functioning of tissues and organs.
For more NCERT Solutions of Class 9 Science Exploration Chapter 2 Cell: The Building Block of Life (2026-27)
https://www.tiwariacademy.com/ncert-solutions/class-9/science/exploration-chapter-2/
See less