13 minute read
1. The organisation of the human body
Organism level The human body is ?
The systems are ? such as ?
The organs are ? such as ?
The tissues are ? such as ?
Molecular level Molecules are ? such as ? Biomolecules are ?
Cellular level
Cells are ?
Human cells
are ? such as ? They group together to form organelles such as ?
2 Write your own unit summary based on the outline below: • What is the difference between the atomic and molecular levels of organisation? Include definitions of bioelement and biomolecule. • Give a definition of cell. What higher levels are cells organised into? • What is the cell membrane composed of? What are its functions? • List the parts of a cell nucleus and explain their functions. • Write a list of the membranous organelles and the non-membranous organelles. What is the difference between them? What is the main function of each one? • Explain what cell differentiation is. • Name the different types of human tissue. What are the main characteristics of each type? • Name the different systems in the human body and the function they are involved in.
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4 Look at the following pictures of tissues and cells and answer the questions:
A B
C D
a) What types of tissues and cells are shown? b) Link each cell to the tissue it forms part of. c) What is the function of each type of tissue? d) What characteristics of each cell type make them suitable for the function they perform in the human body? 5 What cell structure can you see in the following image? What is it composed of? What level of organisation of living matter does it correspond to?
anayaeducacion.es Go to the Science Workshops ‘Observing mucosa cells’ and ‘Studying how transport occurs through the membrane’ in your resource bank. 6 State what level of organisation in the human body the following correspond to: calcium; kidney; nucleus; group made up of the mouth, oesophagus, stomach, intestine, pancreas, etc.; spermatozoa; protein. 7 Copy and correct the following incorrect sentences about the cell membrane: a) The cell membrane isolates the cytoplasm from the outside. b) The plasma membrane is formed of a double layer of proteins. c) Medium-sized substances cross the cell membrane freely and without any help. d) Small substances enter the cell by endocytosis. e) The plasma membrane is not present in all cells. 8 What is the difference between: a) The nucleus and the nucleolus? b) Chromatin and chromosomes? c) The nucleolus and nucleoplasm? 9 List the names of the cell organelles in a table.
Add another column to describe the shape of each organelle, accompanied by a drawing, and another column for its function. 10 Copy the following sentences and say which tissue they refer to: a) Its matrix is liquid and is called plasma. b) It forms glands, which secrete substances. c) Its matrix is solid and elastic. We find it between the vertebrae and in the ear. d) It has a protective function in that it lines cavities. e) It contains low levels of intercellular substance and its cells store fat. f) Its cells transmit nerve impulses. g) Its cells are elongated and it is responsible for body movement. h) Its matrix is solid and contains calcium salts. 11 Why is cell differentiation important? Provide two examples.
anayaeducacion.es Go to ‘Key concepts’ and ‘Learn by playing’ in your resource bank. Invented in the 16th century, the microscope is a key tool for studying cells. As more and more powerful microscopes were developed, scientists were able to make discoveries about cellular structure. The ‘power’ of a microscope is its resolution; that is, the smallest distance by which two points can be seperated and still seen as separate points. Optical microscopes use visible light, which passes through the sample and provides an image that is magnified by a set of lenses. Their resolution is 0.2 μm. Electron microscopes don’t use light, but rather a beam of electrons. These either pass through the sample or bounce off it and are then captured by a screen, where the image appears. Their resolution is 5 μm.
a) What type of microscope has been used to take these pictures of red blood cells? b) If the diameter of a red blood cell is approximately 5 μm, how much magnification does each microscope provide? 13 Many of the body’s cells have names related to the organ they belong to. Search for a picture of each of the following cells and indicate which organ they belong to: hepatocyte, osteocyte, myocyte, chondrocyte.
Sustainable Development Goals
14 Sustainable Development Goal 3 aims to ensure healthy lives and promote well-being for all. The UN has set numerous targets for this goal. a) In groups, find out about the targets of Goal 3 at anayaeducacion.es. Choose the target that most interests your group, and research it. b) Prepare a presentation to give to your class about the importance of your group’s chosen target and what could be done to achieve it. c) Discuss and draw conclusions about the importance of education and research in achieving this goal.
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Assessment On these pages, students are given a series of activities to check what they have learnt. We also suggest you remind your students of the importance of compiling work materials from each unit for their portfolio. Developing thinking Remember to read the document titled ‘Project Keys’ to teach students how to draw a chain of sequences for activity 1. ICT The following resources are available: • Science workshops: ‘Observing mucosa cells’ and
‘Studying how transport occurs through the membrane’ in the resource bank. • ‘Key concepts’, which lets students review the fundamental concepts, and ‘Learn by playing’, which lets students check their learning progress in an entertaining way. SDG commitment Students have access to videos about the targets of ‘Goal 3’, which provide information that will help them with activity 14. Enterprising culture Remember to read the document titled ‘Project Keys’, which provides information on the elements and aspects that students work on in this key. 3 The aim of this activity is for students to review the structure of a cell, by copying a drawing into their notebooks and indicating the name and function of the labelled structures. 1. Nucleus. Contains the genetic material (DNA), which controls cell activity. 2. Cell membrane or plasma membrane. Surrounds the cell, protects it and regulates substance exchange with the outside environment. 3. Cytoplasm. Contains many substances and the cell organelles, and is the medium in which many of the cell’s vital chemical reactions take place. 4. Mitochondrion. Obtains energy through cellular respiration. 5. Cytoskeleton. Directs cell movements, gives the cell its shape and holds the organelles in place. 6. Golgi apparatus. Modifies the substances synthesised in the endoplasmic reticulum and packages them into vesicles to be transported outside the cell. 7. Endoplasmic reticulum. The rough endoplasmic reticulum synthesises proteins, thanks to the ribosomes attached to its membrane, and the smooth endoplasmic reticulum synthesises lipids. 8. Vesicle. Stores and transports substances. 9. Ribosome. Synthesises proteins. 4 We ask students to identify the tissues in the pictures based on the characteristics they have studied, and to indicate how the specialisation of their cells helps them perform their functions. a) 1. Epithelial tissue. 2. Reticular connective tissue. 3. Nervous tissue. 4. Muscle tissue. b) Epithelial tissue lines and protects the internal and external surfaces of organs and the organism’s body; reticular connective tissue fills the space between organs, keeping them in place, and forms tendons; nervous tissue transmits information in the form of nerve impulses; and muscle tissue is responsible for body movement. c) Epithelial cells have a regular shape and are arranged with very little space between them, which allows them to cover and line surfaces; these cells and the many fibres surrounding them are able to fill the space between organs; neurons have projections with which they communicate with other neurons, allowing them to transmit information in the form of nerve impulses; muscle cells are elongated and are able to contract and relax, so they can carry out the functions of body movement. 5 The picture shows metaphase chromosomes, the state chromatin is in during cell division.
Chromosomes are made up of DNA, which contains the genetic information, and proteins that help condense it, both in chromatin fibres and in chromosomes. The level of organisation is a large-scale molecular level, known as the macromolecular level, since they are made up of many molecules and form a large structure.
Applying your knowledge
6 Calcium: atomic level; kidney: organ level; nucleus: organelle level; group made up of the mouth, oesophagus, stomach, intestine, pancreas, etc.: system level; spermatozoa: cellular level; protein: molecular level. 7 a) The cell membrane separates the cytoplasm from the outside (it doesn’t isolate it, since it regulates substance exchange with the environment). b) The plasma membrane is formed of a double layer of lipids (not proteins). c) Small (not medium-sized) substances cross the cell membrane freely and without any help. d) Large substances (not small substances) enter the cell by endocytosis. e) The plasma membrane is present in all cells. 8 a) The function of the nucleus is to contain the genetic information that controls cell activity, whereas the function of the nucleolus is to synthesise the component parts of ribosomes. The nucleus is surrounded by a membrane, whereas the nucleolus does not have a membrane. b) Chromatin is the form DNA is in when the cell is not dividing. Chromosomes are the form DNA is in when the cell is dividing. c) The nucleolus is the area of the nucleus where the component parts of chromosomes are synthesised, whereas nucleoplasm is the aqueous liquid found inside the nucleus.
The systems are ? such as ?
The organs are ? such as ?
The tissues are ? such as ?
Molecular level Molecules are ? such as ? Biomolecules are ?
Cellular level
Cells are ?
Human cells
are ? such as ? They group together to form organelles such as ?
2 Write your own unit summary based on the outline below: • What is the difference between the atomic and molecular levels of organisation? Include definitions of bioelement and biomolecule. • Give a definition of cell. What higher levels are cells organised into? • What is the cell membrane composed of? What are its functions? • List the parts of a cell nucleus and explain their functions. • Write a list of the membranous organelles and the non-membranous organelles. What is the difference between them? What is the main function of each one? • Explain what cell differentiation is. • Name the different types of human tissue. What are the main characteristics of each type? • Name the different systems in the human body and the function they are involved in.
G
F
E D
4 Look at the following pictures of tissues and cells and answer the questions:
A B
C D
a) What types of tissues and cells are shown? b) Link each cell to the tissue it forms part of. c) What is the function of each type of tissue? d) What characteristics of each cell type make them suitable for the function they perform in the human body? 5 What cell structure can you see in the following image? What is it composed of? What level of organisation of living matter does it correspond to?
anayaeducacion.es Go to the Science Workshops ‘Observing mucosa cells’ and ‘Studying how transport occurs through the membrane’ in your resource bank. 6 State what level of organisation in the human body the following correspond to: calcium; kidney; nucleus; group made up of the mouth, oesophagus, stomach, intestine, pancreas, etc.; spermatozoa; protein. 7 Copy and correct the following incorrect sentences about the cell membrane: a) The cell membrane isolates the cytoplasm from the outside. b) The plasma membrane is formed of a double layer of proteins. c) Medium-sized substances cross the cell membrane freely and without any help. d) Small substances enter the cell by endocytosis. e) The plasma membrane is not present in all cells. 8 What is the difference between: a) The nucleus and the nucleolus? b) Chromatin and chromosomes? c) The nucleolus and nucleoplasm? 9 List the names of the cell organelles in a table.
Add another column to describe the shape of each organelle, accompanied by a drawing, and another column for its function. 10 Copy the following sentences and say which tissue they refer to: a) Its matrix is liquid and is called plasma. b) It forms glands, which secrete substances. c) Its matrix is solid and elastic. We find it between the vertebrae and in the ear. d) It has a protective function in that it lines cavities. e) It contains low levels of intercellular substance and its cells store fat. f) Its cells transmit nerve impulses. g) Its cells are elongated and it is responsible for body movement. h) Its matrix is solid and contains calcium salts. 11 Why is cell differentiation important? Provide two examples.
anayaeducacion.es Go to ‘Key concepts’ and ‘Learn by playing’ in your resource bank. Invented in the 16th century, the microscope is a key tool for studying cells. As more and more powerful microscopes were developed, scientists were able to make discoveries about cellular structure. The ‘power’ of a microscope is its resolution; that is, the smallest distance by which two points can be seperated and still seen as separate points. Optical microscopes use visible light, which passes through the sample and provides an image that is magnified by a set of lenses. Their resolution is 0.2 μm. Electron microscopes don’t use light, but rather a beam of electrons. These either pass through the sample or bounce off it and are then captured by a screen, where the image appears. Their resolution is 5 μm.
a) What type of microscope has been used to take these pictures of red blood cells? b) If the diameter of a red blood cell is approximately 5 μm, how much magnification does each microscope provide? 13 Many of the body’s cells have names related to the organ they belong to. Search for a picture of each of the following cells and indicate which organ they belong to: hepatocyte, osteocyte, myocyte, chondrocyte.
Sustainable Development Goals
14 Sustainable Development Goal 3 aims to ensure healthy lives and promote well-being for all. The UN has set numerous targets for this goal. a) In groups, find out about the targets of Goal 3 at anayaeducacion.es. Choose the target that most interests your group, and research it. b) Prepare a presentation to give to your class about the importance of your group’s chosen target and what could be done to achieve it. c) Discuss and draw conclusions about the importance of education and research in achieving this goal.
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Assessment On these pages, students are given a series of activities to check what they have learnt. We also suggest you remind your students of the importance of compiling work materials from each unit for their portfolio. Developing thinking Remember to read the document titled ‘Project Keys’ to teach students how to draw a chain of sequences for activity 1. ICT The following resources are available: • Science workshops: ‘Observing mucosa cells’ and
‘Studying how transport occurs through the membrane’ in the resource bank. • ‘Key concepts’, which lets students review the fundamental concepts, and ‘Learn by playing’, which lets students check their learning progress in an entertaining way. SDG commitment Students have access to videos about the targets of ‘Goal 3’, which provide information that will help them with activity 14. Enterprising culture Remember to read the document titled ‘Project Keys’, which provides information on the elements and aspects that students work on in this key.
