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Higher human biology

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Title: Higher human biology


1
Higher human biology
  • Unit 1 human cells

2
  • 1 Division and differentiation in human cells
  • Cellular differentiation is the process by which
    a cell develops more specialised functions by
    expressing the genes characteristic for that type
    of cell.
  • (a) Stem cells embryonic and tissue (adult)
    stem cells.
  • Stem cells are relatively unspecialised cells
    that can continue to divide and can differentiate
    into specialised cells of one or more types.
    During embryological development the
    unspecialised cells of the early embryo
    differentiate into cells with specialised
    functions. Tissue (adult) stem cells replenish
    differentiated cells that need to be replaced and
    give rise to a more limited range of cell types.

3
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4
Some questions to think about
  • What is a cell?
  • What varieties of cell exist?
  • What is a tissue? Give some examples.
  • What is an organ? Give some examples.
  • What is a system? Give some examples.

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6
Bozeman biology
  • https//www.youtube.com/watch?vjp6L5emD8rw

7
Specialised cells
  • The human body is made up of many specialised
    cells that have specific structural, functional
    and biochemical properties
  • Specialised cells arise from the differentiation
    of unspecialised cells during embryo development.
  • Specialised cells with similar functions are
    grouped into tissues. Similar tissues are grouped
    into organs and similar organs are grouped into
    systems.

8
Specialised cells
  • https//www.twigonglow.com/films/different-types-o
    f-cell-1042/
  • Differentiation short film

9
Why have specialised cells?
  • Division of Labour
  • Multicellular organisms have millions of cells
  • To ensure all process carried out division of
    labour where cells become differentiated and
    specialised to carry out 1 specific function

10
  • Cell differentiation is under genetic control and
    involves cell signalling processes.
  • During differentiation, genes that express
    proteins important for the function of that cell
    remain switched on.
  • Once a cell becomes specialised, it stops
    dividing and only expresses the genes are
    characteristic for that type of cell.

11
Differentiation
  • During differentiation, certain genes that
    express proteins important for the function of a
    specific cell are switched on. This allows it
    to develop a more specialised structure to carry
    out a specific function.
  • Once a cell becomes differentiated it only
    expresses the genes that produce the proteins
    characteristic for that type of cell.

12
Stem cells
  • Some questions to think about
  • What is a stem cell?
  • What are some different types of stem cells?
  • What is the purpose of stem cell research?
  • What are some ways that stem cells have been
    successfully used in medicine?
  • What are some of the issues in stem cell
    research?
  • What are some of the misconceptions that people
    have about stem cell research?

13
Stem cells film
  • http//www.educationscotland.gov.uk/video/h/video_
    tcm4664297.asp?strReferringChannelhighersciences
    strReferringPageIDtcm4-665932-64classl3d14245
    6d143862

14
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15
What is a stem cell?
16
Why self-renew AND differentiate?
1 stem cell
4 specialized cells
1 stem cell
Differentiation - replaces dead or damaged cells
throughout your life
Self renewal - maintains the stem cell pool
17
Stem cell development animation
18
What are stem cells?
Stem cells are unspecialised cells that have the
ability to reproduce to make more stem cells or
differentiate into specialised cells of one or
more types.
19
Stem cell jargon/definitions
Potency A measure of how many types of
specialized cell a stem cell can make
Stem cell type Description Examples
Totipotent Each cell can develop into a new individual Cells from early (1-3 days) embryos (zygote)
Pluripotent Cells can form any (over 200) cell types Some cells of blastocyst (5 to 14 days)
Multipotent Cells differentiated, but can form a number of other tissues Fetal tissue, cord blood, and adult stem cells
Unipotent ???? Spermatogonial cells in testicles only make sperm
20
Types of stem cells
Embryonic
Adult
21
Embryonic stem cells
22
Embryonic stem cells
  • Embryonic stem cells are derived from
    unspecialised cells found within an embryo.
  • They have the ability to differentiate into all
    cell types that make up an organism.

23
Where are stem cells found?
zygote stem cells Totipotent can diffrerentiate
into all cells and placenta/ umbilical cord etc.
tissue stem cells fetus, baby and throughout life
embryonic stem cells blastocyst - a very early
embryo about 50-100 cells
24
Adult (tissue) stem cells
25
  • Do adult vs embryo stem cell card sort!

26
Adult (tissue) stem cells
  • Adult or tissue stem cells are found in various
    tissues of adults and children, including the
    brain, bone marrow, skeletal muscle and skin.
  • These cells replenish differentiated cells that
    need replaced through age or damage in the
    tissues in which they are found. They are able to
    differentiate into a much more limited range of
    cell types and will tend to develop into cell
    types that are closely related to the tissue in
    which they are found.
  • Eg adult stem cells in bone marrow will produce
    red blood cells, platelets, phagocytes and
    lymphocytes.

27
Other types of stem cells
  • Stem cells can also be taken from the umbilical
    cord of new babies.
  • Like adult stem cells, these cells can
    differentiate into a limited range of specialised
    cells.

28
Induced pluripotent stem cells- the exception to
the rule!
Induced pluripotent stem (iPS) cells are adult
cells that have had their nucleus genetically
reprogrammed to an embryonic stem cell-like state.
29
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30
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31
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32
  • (b) Somatic cells divide by mitosis to form more
    somatic cells. These differentiate to form
    different body tissue types epithelial,
    connective, muscle and nerve.

33
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34
What do you think somatic cells are? Look at the
pictures..
B Lymphocyte
Smooth muscle
cartilage
35
Somatic cells
neutrophil
Ciliated epithelial cell
Red blood cell
platelets
36
Somatic cells
Cardiac muscle
Squamous epithelial cells
Nerve cells
T lymphocyte
37
Somatic cells
All body cells (except gametes and the cells
which make them) are called somatic cells. They
divide by mitosis and differentiate to form more
cells of that tissue. Mutations that occur in
somatic cells arent passed onto offspring.
38
  • Do somatic cell passport activity

39
Tissues and organs
  • Body organs are formed from a variety of tissues
    made from somatic cells. E.g.
  • Epithelial cells which cover the body surface and
    line body cavities (E.g bladder, respiratory etc)
  • Connective tissue includes blood, bone and
    cartilage cells
  • Muscle cells form muscle tissue
  • Nerve cells form nervous tissue

40
Give an account, with examples, of the different
body tissue types and their functions. (8 marks)
  1. Body tissue cells derive from somatic stem cells
  2. by repeated mitosis.
  3. Epithelial tissue - covers the organ surfaces.
  4. Protection - skin / secretion - intestinal glands
    / absorption - villi.
  5. Connective tissue - gives shape to organs and
    supports them.
  6. Protection - skull bones / structural framework -
    ribs / storage of energy - adipose tissue /
    connecting body organs - blood / connecting
    epithelial to muscle tissue - cartilage (in
    tendons)
  7. Muscle tissue - which causes locomotion or
    movement within organs.
  8. Skeletal muscle - locomotion / smooth muscle - in
    arterioles control of access to capillary bed /
    cardiac muscle - contraction of the heart.
  9. Nervous tissue - which transmits messages between
    the central nervous system and the rest of the
    body (and within the central nervous system).
  10. Neurons - conduct impulses / glial cells -
    maintain a constant environment for neurons.

41
  • (c) Germline cells divide by mitosis to produce
    more germline cells or by meiosis to produce
    haploid gametes. Mutations in germline cells are
    passed to offspring. Mutations in somatic cells
    are not passed to offspring.

42
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43
What do you think germline cells are?
44
Division of germline cells
  • Germline cells can divide by mitosis to produce
    more germline cells.
  • Germline cells can divide by meiosis to produce
    gametes.

45
Germline cells
Gametes and the cells that produce the gametes
are called germline cells. They divide either by
mitosis to produce more germline cells or by
meiosis to produce gametes. Mutations that occur
in germline cells are passed onto offspring
46
  • Stage 1 chromosomes copy themselves
  • Stage 4 homologous pairs of chromosomes line up
    at equator
  • Stage 5- chromosomes pulled apart by spindle
    fibres
  • Stage 6 2 cells formed
  • Stage 8 individual chromosomes line up at
    equator
  • Stage 9 chromosomes pulled apart by spindle
    fibres
  • Stage 10 gamete cells formed with half a
    chromosome complement

47
Give an account of cell differentiation under the
following headingsstem cells somatic
cellsgermline cells
48
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49
  • (d) Research and therapeutic uses of stem cells
    by reference to the repair of damaged or diseased
    organs or tissues. Stem cells can also be used as
    model cells to study how diseases develop or for
    drug testing. The ethical issues of stem cell use
    and the regulation of their use.

50
(No Transcript)
51
Stem cell research
  • http//www.educationscotland.gov.uk/video/h/video_
    tcm4664297.asp?strReferringChannelhighersciences
    strReferringPageIDtcm4-665932-64classl3d14245
    6d143862

52
Therapeutic stem cells
  • https//www.twigonglow.com/films/therapeutic-stem-
    cells-1066/

53
TED talk Anthony Atala Growing new organs
  • http//www.ted.com/talks/anthony_atala_growing_org
    ans_engineering_tissue?languageen

54
Stem cell research
  • Stem cell research provides us with a wealth of
    information and can be studied in a variety of
    ways, including
  • how cell processes such as growth,
    differentiation and gene regulation work
  • the study of diseases and their development
  • drug testing
  • therapeutic uses in the treatment of diseases
    such as leukaemia (bone marrow transplant),
    Hunters disease and heart disease
  • therapeutic uses in medicine, including skin
    grafts for burns and stem cell grafts for cornea
    repair.

55
For example, stem cells could be turned into new
bone cells and then injected into weak or broken
bones to speed up healing time.
56
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57
Windpipe Transplant
  • http//www.bbc.co.uk/learningzone/clips/woman-gets
    -windpipe-transplant/5857.html

58
  • Or they could become nerve cells that could heal
    spinal cord injuries.

59
  • Skin cells could replace burnt skin, and brain
    cells could help people who have suffered brain
    damage.

60
  • Stem cells could be taken from someone with heart
    disease and be turned into heart cells, which can
    gather in a dish and throb! They could then be
    injected back into the patient to rebuild their
    heart tissue and combat heart disease.
  • Beating heart cells in a dish! http//www.youtube.
    com/watch?vRO4pAc21M24

61
  • Symptoms mask-like face, stiffness and tremors
    until sufferers eventually become immobile.
  • Replacing the affected brain cells seems more
    hopeful than finding better drugs. Many people
    think that stem cells could be grown into new
    brain cells that could help to treat or even cure
    Parkinson's.

62
Therapeutic stem cell cloning
63
Stem cell uses
  • Model cells to study how diseases develop
  • Drug testing
  • Tissue replacement
  • e.g. skin grafting for burn patients
  • heart tissue for heart disease patients
  • brain nerve cells for Parkinsons sufferers
  • blood for transfusion
  • nerve cells for spinal cord injuries

64
  • Do stem cell newspaper report activity

65
Corneal stem cell transplant
  • https//www.youtube.com/watch?vnHK0Lp1jJnw 2
    mins
  • https//www.youtube.com/watch?vPJbdbAPXA7c 2
    mins
  • https//www.youtube.com/watch?veM9IzlK0uv8 25
    mins

66
Corneal stem cell therapy
  • Stem cells extracted from healthy eye, cultured
    (grown) and transplanted back into the damaged
    eye
  • Repairs cornea
  • Shorter waiting time than traditional donation
  • Reduced chance of rejection as patients own
    cells transplanted

67
Describe how stem cells have contributed
tocorneal transplants and skin grafts. 
  • Corneal transplants 
  • stem cells isolated from the patient's healthy
    eye
  • new tissue can be cultured/grown
  • transplanted back into the damaged eye,
  • repair the damaged cornea.
  • Shorter waiting time than corneal donation
  • Skin grafts 
  • Stem cells isolated from healthy skin
  • New tissue grown / cultured
  • dehydration and infection are risks until graft
    done.
  • Produces skin cells much more quickly.
  • reduces the time patient at risk.

68
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69
Presentation task
  • Using what you have learned already and adding
    further research, create a presentation that
    covers the following aspects of stem cells
  • the biology of stem cells what is a stem cell,
    types of stem cells
  • the potential of stem cells details of one or
    two research projects involving stem cells that
    you have found particularly interesting, details
    of potential therapies
  • stem cell dilemmas explore the moral and
    ethical issues surrounding stem cell research
    (personal points of view can be expressed if
    desired).
  • You will be assessed using all three of the above
    criteria as well as on the overall quality of
    your presentation.

70
  • www.sscn.co.uk
  • www.allthingsstemcell.com
  • www.hypeandhope.com
  • www.abpischools.org.uk click interactive, 14-16,
    biology, then stem cell research
  • http//www.hhmi.org/biointeractive/click/index.htm
    l
  • http//learn.genetics.utah.edu/content/stemcells/
  • www.cells4life.co.uk

71
Criteria 4 3 2 1
The biology of stem cells Covers the topic in depth with details and examples. All key terms and words have been defined. Subject knowledge is excellent. Includes essential knowledge about the topic. Subject knowledge is good. Includes most information about the topic but there are some factual errors/omissions. Content is minimal and there are several factual errors/omissions.
The potential of stem cells More than one example of stem cell research has been covered in depth. More than one example of potential stem cell therapies has been explored. At least one example of stem cell research has been covered in depth. Potential stem cell therapies have been covered. An example(s) has been covered but is lacking in depth and detail of information. Examples are minimal. Very few details given.
Stem cell dilemmas The moral and ethical issues surrounding stem cell research have been explored in detail. More than one perspective has been given for many issues. The moral and ethical issues surrounding stem cell research have been covered well. More than one perspective has been given for some issues. Some moral and ethical issues have been mentioned but lack detail. Arguments detailed not balanced/only one perspective given. Very little detail given in this area.
Quality of presentation Interesting, well rehearsed, all members of group involved, word content of slide minimal, good eye contact with audience, smooth delivery. Relatively interesting, fairly smooth delivery. Eye contact mainly good and most members of group involved at some stage. Able to maintain interest of audience but delivery not smooth. Failed to make eye contact on some occasions. Some group members not involved. Poor eye contact, not able to maintain interest of audience. Reading from slides, delivery not smooth.
72
The ethical issues of stem cell use
  • http//www.playbackschools.org.uk/programme/3144/s
    tem-cell-research-the-issue
  • (15min)

73
Stem cell views
  • http//www.pbslearningmedia.org/resource/tdc02.sci
    .life.cell.stemcellvid/stem-cells-seeds-of-hope/

74
  • Watch the clip on stem cell research and answer
    the following questions
  • http//www.pbslearningmedia.org/resource/tdc02.sci
    .life.cell.stemcellvid/stem-cells-seeds-of-hope/
    (7min)
  • What does Dr Snyder mean when he says stem cells
    are "flexible and plastic?"
  • In this video what evidence convinces you that
    stem cells can be used to cure spinal cord
    injury?
  • Dr Snyder points out that there are ethical
    concerns, and that there is no single answer that
    will please everyone. Who do you think should be
    the ones to decide where to obtain stem cells for
    medical research?

75
  • Do stem cell card sort for and against

76
Not in our back yard!
  • Should a business license be issued to ESC
    lifeworks Inc. by the city of Dundee?

Debate the issue- use the hand out to help
organise the structure of the debate
77
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79
Some useful Video Clips Stem Cells and Ethics
  • http//www.educationscotland.gov.uk/video/h/video_
    tcm4664297.asp?strReferringChannelhighersciences
    strReferringPageIDtcm4-658424-64classl3d14245
    6d143862
  • http//www.bbc.co.uk/learningzone/clips/stem-cell-
    research-and-medicine/6013.html
  • http//www.bbc.co.uk/learningzone/clips/ethics-of-
    using-foetal-stem-cells-for-stroke-treatment/5888.
    html
  • http//www.bbc.co.uk/learningzone/clips/alternativ
    e-to-embryo-stem-cells-developed-by-researchers/65
    81.html
  • http//www.bbc.co.uk/programmes/p00k7j7w
  • http//www.bbc.co.uk/learningzone/clips/stem-cell-
    research/14287.html

80
Ethical issues surrounding stem cells
  • Practices using adult (tissue) stem cells remain
    fairly uncontroversial.
  • Many pro-life and religious groups argue that
    embryos have human rights, should not be
    destroyed and should not be created simply for
    scientific research.
  • Opposing arguments include the potential to
    discover cures for diseases for which there are
    currently none and improved treatment of a range
    of medical conditions.

81
Regulation of stem cell use
  • The laws surrounding embryonic stem cells and
    adult stem cells differ because while both have
    similar capacities in differentiation, their
    modes of derivation are not.
  • While embryonic stem cells are taken from
    embryos, adult cells can be taken from consenting
    adults.

82
Regulations surrounding the use of embryonic stem
cells
  • The research must be licensed by the Human
    Fertilisation and Embryology Authority (HFEA).
  • Researchers must justify that the creation of an
    embryo is necessary and that the work could not
    be carried out in another way.
  • Embryos over the development stage of 14 days
    cannot be used as this is the stage at which
    there is some primitive development of the
    nervous system.

83
  • The use of stem cells in therapeutic treatments
    in the UK is currently restricted to adult stem
    cells.
  • Whether or not embryonic stem cells can be used
    in the future remains to be seen.

84
Cloning
85
Cloning
  • Human reproductive cloning is illegal in the UK.
    As a result of the Human Reproductive Cloning Act
    (2001) nobody in the UK is allowed to use cell
    nuclear transfer, or any other technique, to
    create a child.

86
Regulations surrounding stem cell use
  • Research must be licensed by the Human
    Fertilisation and Embryology Authority (HFEA).
  • Researchers must justify that the creation of an
    embryo is necessary and that the work could not
    be carried out in another way.
  • Embryos must be under 14 days old.
  • Human cloning is illegal in the UK

87
Compare the location and functions of embryonic
and tissue (adult) stem cells. (7 marks)
  • Stem cells are undifferentiated cells capable of
    repeated division to both more stem cells and
    cells that will later differentiate to form
    specialised cells.
  • Embryonic stem cells (ESCs) are found in the
    inner cell mass of the blastocyst.
  • ESCs are capable of repeated division
  • to form more ESCs and other cell types.
  • ESCs are capable of forming all the other cell
    types of the body / pluripotent
  • Tissue stem cells (TSCs) are found throughout the
    juvenile and adult body.
  • TSCs are capable of repeated division to form
    more TSCs and other cell types.
  • TSCs can only form cells of the organ to which
    they belong / are multipotent.
  • e.g. bone marrow tissue cells can only give rise
    to bone marrow cells, red blood cells, platelets,
    phagocytes and lymphocytes.

88
  • (e) Cancer cells divide excessively to produce a
    mass of abnormal cells (a tumour) that do not
    respond to regulatory signals and may fail to
    attach to each other. If the cancer cells fail to
    attach to each other they can spread through the
    body to form secondary tumours.

89
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90
Stuart brown stooibrown_at_yahoo.com
  • Cancer.  I worked for ten years in the Dept of
    Surgical Molecular Oncology at Ninewells so I
    can speak a bit about how cancer is researched
    and treated although there's not a lot I can say
    about pharmaceutical therapies - that stuff just
    went way over my head.  However, I can talk about
    the bowel cancer screening programme, for example
    and that might fit not just with this module but
    also with the public health bit later in the
    syllabus.  I also worked on x-ray ablation of
    breast cancer, cryogenic and thermal ablation of
    solid-organ cancers and a lot on colon cancer
    surgery.  Another thing I'm quite familiar with
    is the use of nanoparticles and microbubbles to
    pursue novel cancer therapies

91
What is cancer?
  • https//www.twigonglow.com/films/what-is-cancer-15
    80/

92
TED talk
  • http//www.ted.com/talks/deborah_gordon_what_ants_
    teach_us_about_the_brain_cancer_and_the_internet

93
Reverse the odds app
  • http//www.mavericktv.co.uk/news/emmy-nomination-f
    or-reverse-the-odds/

94
Cancer cells
  • Cancer cells continue to reproduce to produce a
    mass of abnormal cells (a benign tumour).
  • They do not respond to normal regulatory signals
    that would instruct them to stop dividing when
    necessary.
  • They lose the molecules on their surface that
    would normally hold them in place and can
    therefore be detached from their neighbours,
    causing the cells to spread (malignant tumour).

Skin cancer cells (melanoma)
95
  • It is thought that 9095 of cancers are caused
    by environmental and lifestyle factors such as
    obesity and tobacco.
  • It is estimated that 510 are due to genetics.

96
HPV environmental factors
  • Certain strains of the human papilloma virus
    (HPV) have been shown to cause cervical cancer.
  • The routine immunisation programme in Scotland is
    for girls aged 12 and 13 (S2). There is also a
    one-off, three-year catch-up programme for older
    girls.

97
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99
  • Watch melanoma film

100
UV sensitive yeast
  • UV sensitive strain of yeast Bakers yeast
    solution (saccharomyces cerevisiae) kept covered
    in foil.
  • Yeast glucose agar dish divided into 3 sections
    sun with sunscreen / sun with no sunscreen / no
    sun
  • Use aseptic techniques
  • Expose to sunlight for 15 mins on bright day or
    longer on less bright day (or UV light)
  • Incubate 3-4 days at room temp 1-2 days at 30
    degrees.
  • Count the number of colonies

101
Cancer
  • Cancer cells divide excessively to produce a mass
    of abnormal cells (called a tumour).
  • They do not respond to regulatory signals that
    would instruct them to stop dividing when
    necessary.
  • They may fail to attach to each other, called
    malignant tumours. This means they can spread
    throughout the body, forming secondary tumours.

102
Super Science Nanotechnology
  • https//www.youtube.com/watch?va8FM9umJXvo
  • Imagine a tiny robot the size of a human cell,
    injected by the millions into your bloodstream on
    a search and destroy mission to locate cancer
    cells, and kill them. Welcome to the scientific
    frontier of nanotechnology.

103
Your task
  • Produce an information leaflet designed to answer
    the questions of a patient recently diagnosed
    with cancer. Points to consider
  • How are cancer cells different from other cells?
  • What is a tumour?
  • How will I know if my cancer has spread?
  • What is the difference between a malignant tumour
    and a benign tumour?
  • How will my cancer be treated?
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