(a)Characteristics of living organisms
1.1 Understand how living organisms share the following characteristics:
They require nutrition: Through the consumption of food or other sources.
They respire: Living organisms require oxygen to carry out cellular respiration and produce energy.
They excrete their waste: Living organisms produce waste products because of metabolic processes.
They respond to their surroundings: Living organisms can sense and respond to changes in their
environment.
They move: Living organisms can move from one place to another.
They control their internal conditions: Living organisms can maintain homeostasis and regulate their
internal environment despite changes in external conditions.
They reproduce: Living organisms can reproduce and pass on their genetic information to their offspring.
They grow and develop: Living organisms can grow and develop throughout their lifetime.
(b)Variety of living organisms
1.2 describe the common features shown by eukaryotic organisms: plants, animals, fungi
and Protoctists.
Plants are multicellular organisms that carry out photosynthesis, have cellulose cell walls, and store
carbohydrates as starch. Examples include like peas or beans.
Animals are multicellular organisms without cell walls, cannot carry out photosynthesis, often have
nervous coordination and can move, and store carbohydrate as glycogen. Examples include mammals like
humans and insects.
Fungi are non-photosynthetic organisms that have a mycelium made from thread-like hyphae containing
many nuclei, with walls made of chitin, and obtain nutrients through saprotrophic nutrition. They may
store carbohydrate as glycogen and examples include Mucor with typical fungal hyphal structure and
single-celled yeast.
Protoctists are microscopic single-celled organisms, some like Amoeba have animal cell-like features,
while others like Chlorella have chloroplasts and are like plants. Pathogenic examples include
Plasmodium which causes malaria.
1.3 Describe the common features shown by prokaryotic organisms such as bacteria.
Bacteria are single-celled microorganisms with a cell wall, cell membrane, cytoplasm, and plasmids,
lacking a nucleus but containing a circular DNA chromosome; they can carry out photosynthesis or feed
off living or dead organisms. Examples include Lactobacillus bulgaricus used in yoghurt production and
Pneumococcus, a pathogen causing pneumonia.
,1.4 Understand the term pathogen and know that pathogens may include fungi, bacteria,
Protoctists or viruses.
Viruses are not living organisms, they are parasitic particles smaller than bacteria that can only reproduce
inside living cells, infecting every type of organism with a protein coat and containing one type of nucleic
acid, either DNA or RNA, and examples include the tobacco mosaic virus, influenza virus, and HIV
virus.
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2) Structure and functions in living organisms
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(a)Level of organization
2.1 Describe the levels of organization in organisms: organelles, cells, tissues, organs,
and systems.
Organelles are specialized structures within cells,
Cells are the basic units of life,
Tissues are groups of similar cells that work together,
Organs are composed of different tissues that perform a specific function,
Systems are groups of organs that work together to perform a common functio n.
(b)Cell structure
2.2 Describe cell structures, including the nucleus, cytoplasm, cell membrane, cell wall,
mitochondria, chloroplasts, ribosomes, and vacuole.
Nucleus: controls the cell's activities,
Cytoplasm: is a jelly-like substance where chemical reactions happen,
Cell membrane: controls what goes in and out of the cell,
Cell wall: gives the cell support and shape,
Mitochondria: produce energy,
Chloroplasts: carry out photosynthesis,
Ribosomes: make proteins,
Vacuoles: store substances.
2.3 Describe the functions of the nucleus, cytoplasm, cell membrane, cell wall,
mitochondria, chloroplasts, ribosomes, and vacuole.
Nucleus: controls cell activity and contains genetic material
Cytoplasm: where chemical reactions take place
Cell membrane: controls substances entering and leaving the cell.
Cell wall: provides support and protection for plant cells.
Mitochondria: site of aerobic respiration, producing energy for the cell
Chloroplasts: contain chlorophyll and are the site of photosynthesis in plant cells
Ribosomes: site of protein synthesis
Vacuole: stores substances such as water, sugars, and pigments
,2.4 Know the similarities and differences in the structure of plant and animal cells.
Plant and animal cells have similarities, such as a cell membrane, cytoplasm, and a nucleus.
Plant cells have a cell wall made of cellulose and chloroplasts for photosynthesis, while animal cells do
not.
Animal cells have lysosomes, which plant cells do not have.
2.5 Explain the importance of cell differentiation in the development of
specialized cells.
Cell differentiation is the process by which unspecialized cells develop into specialized cells with specific
structures and functions. This is essential for the development of multicellular organisms, as specialized
cells perform specific roles necessary for the organism's survival. For example, muscle cells are elongated
and can contract, while nerve cells have long extensions that allow for the transmission of electrical
impulses. Without cell differentiation, organisms would not be able to perform complex functions and
survive.
2.6 Understand the advantages and disadvantages of using stem cells in
medicine.
Stem cells can differentiate into different types of cells, making them a promising tool for regenerative
medicine. Embryonic stem cells are pluripotent and can differentiate into any type of cell, but their use is
controversial due to ethical concerns. Adult stem cells are multipotent and can differentiate into a limited
number of cell types. The use of stem cells in medicine has potential benefits such as repairing damaged
tissue and treating diseases, but there are also potential risks such as rejection by the immune system and
the formation of tumors.
(c)Biological molecules
2.7 Identify the chemical elements present in carbohydrates, proteins, and lipids (fats
and oils)
Carbohydrates: made up of carbon, hydrogen, and oxygen atoms.
Proteins: made up of carbon, hydrogen, oxygen, and nitrogen, and sometimes sulphur.
Lipids (fats and oils): made up of carbon, hydrogen, and oxygen atoms .
2.8 Describe the structure of carbohydrates, proteins and lipids as large molecules made
up from smaller basic units: starch and glycogen from simple sugars, protein from
amino acids, and lipid from fatty acids and glycerol.
Starch and glycogen are made up of simple sugars,
protein is made up of amino acids,
lipids are made up of fatty acids and glycerol.
Carbohydrates provide energy for the body,
proteins are involved in many cellular functions including building and repairing tissues,
lipids play a role in energy storage and as a component of cell membranes.
2.9 Practical: investigate food samples for the presence of glucose, starch, protein, and
fat.
, You can use various chemical tests. For example,
Benedict's reagent can be used to test for glucose,
Iodine solution for starch,
Biuret reagent for protein,
Sudan III stain for fat.
By following the instructions for each test and observing any color changes, you can determine whether a
particular food sample contains these molecules.
2.10 Understand the role of enzymes as biological catalysts in metabolic reactions.
Enzymes are proteins that act as biological catalysts in metabolic reactions,
Increases the rate of these reactions by lowering the activation energy required for them to occur.
Enzymes are specific to the reactions they catalyze, and their specificity is determined by their three-
dimensional shape.
Enzymes can be affected by factors such as temperature, pH, and inhibitors, which can alter their activity.
2.11 Understand how temperature changes can affect enzyme function, including changes
to the shape of active site.
Enzymes are biological catalysts that speed up metabolic reactions. The shape of the enzyme's active site
is crucial for its function. Changes in temperature can affect enzyme activity by altering the shape of the
active site, making it less effective or completely denaturing the enzyme. Optimum temperature for
enzyme activity varies depending on the type of enzyme, but it's usually around 37°C for human
enzymes.
2.12 Practical: investigate how enzyme activity can be affected by changes in
temperature.
During this practical, the activity of an enzyme will be investigated by observing the effect of temperature
changes on the rate of reaction. The reaction rate will be measured by the time taken for a specific amount
of product to be formed. Different temperatures will be used to investigate the effect on enzyme activity.
The optimal temperature at which the enzyme works best will be observed, as well as the temperature at
which the enzyme activity is completely denatured, meaning that the enzyme loses its shape and can no
longer function.
2.13 Understand how enzyme function can be affected by changes in pH altering the
active site.
Enzyme function can be affected by changes in ph. Each enzyme has an optimum pH range in which it
functions most effectively. A change in pH can alter the active site of the enzyme, making it less effective
or completely inactive.
2.14 Practical: investigate how enzyme activity can be affected by changes in pH
In this practical, the effect of pH on enzyme activity is investigated. Different pH levels are used to
observe the effect on the enzyme's activity. The experiment involves using a specific enzyme and
substrate and measuring the rate of reaction at different pH levels. The results are recorded and analyzed
to determine the optimal pH for the enzyme's activity. This practical helps to understand the importance
of pH in enzyme function and how changes in pH can affect the enzyme's activity.
1.1 Understand how living organisms share the following characteristics:
They require nutrition: Through the consumption of food or other sources.
They respire: Living organisms require oxygen to carry out cellular respiration and produce energy.
They excrete their waste: Living organisms produce waste products because of metabolic processes.
They respond to their surroundings: Living organisms can sense and respond to changes in their
environment.
They move: Living organisms can move from one place to another.
They control their internal conditions: Living organisms can maintain homeostasis and regulate their
internal environment despite changes in external conditions.
They reproduce: Living organisms can reproduce and pass on their genetic information to their offspring.
They grow and develop: Living organisms can grow and develop throughout their lifetime.
(b)Variety of living organisms
1.2 describe the common features shown by eukaryotic organisms: plants, animals, fungi
and Protoctists.
Plants are multicellular organisms that carry out photosynthesis, have cellulose cell walls, and store
carbohydrates as starch. Examples include like peas or beans.
Animals are multicellular organisms without cell walls, cannot carry out photosynthesis, often have
nervous coordination and can move, and store carbohydrate as glycogen. Examples include mammals like
humans and insects.
Fungi are non-photosynthetic organisms that have a mycelium made from thread-like hyphae containing
many nuclei, with walls made of chitin, and obtain nutrients through saprotrophic nutrition. They may
store carbohydrate as glycogen and examples include Mucor with typical fungal hyphal structure and
single-celled yeast.
Protoctists are microscopic single-celled organisms, some like Amoeba have animal cell-like features,
while others like Chlorella have chloroplasts and are like plants. Pathogenic examples include
Plasmodium which causes malaria.
1.3 Describe the common features shown by prokaryotic organisms such as bacteria.
Bacteria are single-celled microorganisms with a cell wall, cell membrane, cytoplasm, and plasmids,
lacking a nucleus but containing a circular DNA chromosome; they can carry out photosynthesis or feed
off living or dead organisms. Examples include Lactobacillus bulgaricus used in yoghurt production and
Pneumococcus, a pathogen causing pneumonia.
,1.4 Understand the term pathogen and know that pathogens may include fungi, bacteria,
Protoctists or viruses.
Viruses are not living organisms, they are parasitic particles smaller than bacteria that can only reproduce
inside living cells, infecting every type of organism with a protein coat and containing one type of nucleic
acid, either DNA or RNA, and examples include the tobacco mosaic virus, influenza virus, and HIV
virus.
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2) Structure and functions in living organisms
_____________________________________________________________________________
(a)Level of organization
2.1 Describe the levels of organization in organisms: organelles, cells, tissues, organs,
and systems.
Organelles are specialized structures within cells,
Cells are the basic units of life,
Tissues are groups of similar cells that work together,
Organs are composed of different tissues that perform a specific function,
Systems are groups of organs that work together to perform a common functio n.
(b)Cell structure
2.2 Describe cell structures, including the nucleus, cytoplasm, cell membrane, cell wall,
mitochondria, chloroplasts, ribosomes, and vacuole.
Nucleus: controls the cell's activities,
Cytoplasm: is a jelly-like substance where chemical reactions happen,
Cell membrane: controls what goes in and out of the cell,
Cell wall: gives the cell support and shape,
Mitochondria: produce energy,
Chloroplasts: carry out photosynthesis,
Ribosomes: make proteins,
Vacuoles: store substances.
2.3 Describe the functions of the nucleus, cytoplasm, cell membrane, cell wall,
mitochondria, chloroplasts, ribosomes, and vacuole.
Nucleus: controls cell activity and contains genetic material
Cytoplasm: where chemical reactions take place
Cell membrane: controls substances entering and leaving the cell.
Cell wall: provides support and protection for plant cells.
Mitochondria: site of aerobic respiration, producing energy for the cell
Chloroplasts: contain chlorophyll and are the site of photosynthesis in plant cells
Ribosomes: site of protein synthesis
Vacuole: stores substances such as water, sugars, and pigments
,2.4 Know the similarities and differences in the structure of plant and animal cells.
Plant and animal cells have similarities, such as a cell membrane, cytoplasm, and a nucleus.
Plant cells have a cell wall made of cellulose and chloroplasts for photosynthesis, while animal cells do
not.
Animal cells have lysosomes, which plant cells do not have.
2.5 Explain the importance of cell differentiation in the development of
specialized cells.
Cell differentiation is the process by which unspecialized cells develop into specialized cells with specific
structures and functions. This is essential for the development of multicellular organisms, as specialized
cells perform specific roles necessary for the organism's survival. For example, muscle cells are elongated
and can contract, while nerve cells have long extensions that allow for the transmission of electrical
impulses. Without cell differentiation, organisms would not be able to perform complex functions and
survive.
2.6 Understand the advantages and disadvantages of using stem cells in
medicine.
Stem cells can differentiate into different types of cells, making them a promising tool for regenerative
medicine. Embryonic stem cells are pluripotent and can differentiate into any type of cell, but their use is
controversial due to ethical concerns. Adult stem cells are multipotent and can differentiate into a limited
number of cell types. The use of stem cells in medicine has potential benefits such as repairing damaged
tissue and treating diseases, but there are also potential risks such as rejection by the immune system and
the formation of tumors.
(c)Biological molecules
2.7 Identify the chemical elements present in carbohydrates, proteins, and lipids (fats
and oils)
Carbohydrates: made up of carbon, hydrogen, and oxygen atoms.
Proteins: made up of carbon, hydrogen, oxygen, and nitrogen, and sometimes sulphur.
Lipids (fats and oils): made up of carbon, hydrogen, and oxygen atoms .
2.8 Describe the structure of carbohydrates, proteins and lipids as large molecules made
up from smaller basic units: starch and glycogen from simple sugars, protein from
amino acids, and lipid from fatty acids and glycerol.
Starch and glycogen are made up of simple sugars,
protein is made up of amino acids,
lipids are made up of fatty acids and glycerol.
Carbohydrates provide energy for the body,
proteins are involved in many cellular functions including building and repairing tissues,
lipids play a role in energy storage and as a component of cell membranes.
2.9 Practical: investigate food samples for the presence of glucose, starch, protein, and
fat.
, You can use various chemical tests. For example,
Benedict's reagent can be used to test for glucose,
Iodine solution for starch,
Biuret reagent for protein,
Sudan III stain for fat.
By following the instructions for each test and observing any color changes, you can determine whether a
particular food sample contains these molecules.
2.10 Understand the role of enzymes as biological catalysts in metabolic reactions.
Enzymes are proteins that act as biological catalysts in metabolic reactions,
Increases the rate of these reactions by lowering the activation energy required for them to occur.
Enzymes are specific to the reactions they catalyze, and their specificity is determined by their three-
dimensional shape.
Enzymes can be affected by factors such as temperature, pH, and inhibitors, which can alter their activity.
2.11 Understand how temperature changes can affect enzyme function, including changes
to the shape of active site.
Enzymes are biological catalysts that speed up metabolic reactions. The shape of the enzyme's active site
is crucial for its function. Changes in temperature can affect enzyme activity by altering the shape of the
active site, making it less effective or completely denaturing the enzyme. Optimum temperature for
enzyme activity varies depending on the type of enzyme, but it's usually around 37°C for human
enzymes.
2.12 Practical: investigate how enzyme activity can be affected by changes in
temperature.
During this practical, the activity of an enzyme will be investigated by observing the effect of temperature
changes on the rate of reaction. The reaction rate will be measured by the time taken for a specific amount
of product to be formed. Different temperatures will be used to investigate the effect on enzyme activity.
The optimal temperature at which the enzyme works best will be observed, as well as the temperature at
which the enzyme activity is completely denatured, meaning that the enzyme loses its shape and can no
longer function.
2.13 Understand how enzyme function can be affected by changes in pH altering the
active site.
Enzyme function can be affected by changes in ph. Each enzyme has an optimum pH range in which it
functions most effectively. A change in pH can alter the active site of the enzyme, making it less effective
or completely inactive.
2.14 Practical: investigate how enzyme activity can be affected by changes in pH
In this practical, the effect of pH on enzyme activity is investigated. Different pH levels are used to
observe the effect on the enzyme's activity. The experiment involves using a specific enzyme and
substrate and measuring the rate of reaction at different pH levels. The results are recorded and analyzed
to determine the optimal pH for the enzyme's activity. This practical helps to understand the importance
of pH in enzyme function and how changes in pH can affect the enzyme's activity.
