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)
Cancer cells arise when normal control over cell division is lost. These cells divide uncontrollably, forming tumours. Malignant tumours can invade nearby tissues and spread to distant parts of the body through blood or lymph. This uncontrolled growth disrupts normal body functions and can become liRead more
Cancer cells arise when normal control over cell division is lost. These cells divide uncontrollably, forming tumours. Malignant tumours can invade nearby tissues and spread to distant parts of the body through blood or lymph. This uncontrolled growth disrupts normal body functions and can become life-threatening if not controlled.
For more NCERT Solutions of Class 9 Science Exploration Chapter 2 Cell: The Building Block of Life (2026-27)
Cells do not grow and reproduce indefinitely. They have a definite life span during which they grow, perform functions, divide and eventually die. This controlled cycle maintains balance in the body. Old or damaged cells are replaced by new ones. If this balance is disturbed, it may lead to diseasesRead more
Cells do not grow and reproduce indefinitely. They have a definite life span during which they grow, perform functions, divide and eventually die. This controlled cycle maintains balance in the body. Old or damaged cells are replaced by new ones. If this balance is disturbed, it may lead to diseases or abnormal conditions.
For more NCERT Solutions of Class 9 Science Exploration Chapter 2 Cell: The Building Block of Life (2026-27)
In 1838, a German botanist named Matthias Schleiden stated that all plants are made up of cells. Later, Theodor Schwann concluded that animals are also made of cells. Rudolf Virchow added that new cells arise from pre-existing cells. Together, these ideas formed the Cell Theory, which explains thatRead more
In 1838, a German botanist named Matthias Schleiden stated that all plants are made up of cells. Later, Theodor Schwann concluded that animals are also made of cells. Rudolf Virchow added that new cells arise from pre-existing cells. Together, these ideas formed the Cell Theory, which explains that cells are the basic structural and functional units of life.
For more NCERT Solutions of Class 9 Science Exploration Chapter 2 Cell: The Building Block of Life (2026-27)
Differentiate 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 lessHow do cancer cells grow and spread?
Cancer cells arise when normal control over cell division is lost. These cells divide uncontrollably, forming tumours. Malignant tumours can invade nearby tissues and spread to distant parts of the body through blood or lymph. This uncontrolled growth disrupts normal body functions and can become liRead more
Cancer cells arise when normal control over cell division is lost. These cells divide uncontrollably, forming tumours. Malignant tumours can invade nearby tissues and spread to distant parts of the body through blood or lymph. This uncontrolled growth disrupts normal body functions and can become life-threatening if not controlled.
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 lessDo cells grow and reproduce forever?
Cells do not grow and reproduce indefinitely. They have a definite life span during which they grow, perform functions, divide and eventually die. This controlled cycle maintains balance in the body. Old or damaged cells are replaced by new ones. If this balance is disturbed, it may lead to diseasesRead more
Cells do not grow and reproduce indefinitely. They have a definite life span during which they grow, perform functions, divide and eventually die. This controlled cycle maintains balance in the body. Old or damaged cells are replaced by new ones. If this balance is disturbed, it may lead to diseases or abnormal conditions.
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 lessCell Theory — The Unifying Principle of Biology. Explain.
In 1838, a German botanist named Matthias Schleiden stated that all plants are made up of cells. Later, Theodor Schwann concluded that animals are also made of cells. Rudolf Virchow added that new cells arise from pre-existing cells. Together, these ideas formed the Cell Theory, which explains thatRead more
In 1838, a German botanist named Matthias Schleiden stated that all plants are made up of cells. Later, Theodor Schwann concluded that animals are also made of cells. Rudolf Virchow added that new cells arise from pre-existing cells. Together, these ideas formed the Cell Theory, which explains that cells are the basic structural and functional units of life.
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