Download Cells and reproduction Jordanhill School S1 Science

Jordanhill School
S1 Science
Cells and reproduction
Name___________________
Teacher_________________
Learning Outcomes
Cells and reproduction
Using a microscope, I have developed my understanding of the structure and variety of cells
and of their functions.
SCN 3-13a
I understand the processes of fertilisation and embryonic development and can discuss
possible risks to the embryo.
SCN 3-14a
□ I can state that a cell is the basic unit of life
□ I can state that living organisms are made up of many cells of different types
□ I know that groups of cells are arranged into tissues, which are organised into
organs which are organised into systems
□ I can state that animal and plant cells contain structures called the nucleus,
cytoplasm and cell membrane
□ I can state that plant cells also contain structures called the cell wall, chloroplasts
and vacuole in addition to those named above
□ I can identify each of these structures on a diagram
□ I can describe the functions of each of the above structures
□ I can state identify all of the main parts of alight microscope and understand how
to look at a slide underneath a microscope
□ I know that before living cells can be viewed underneath a microscope they must
be stained with a chemical to make the structures clearer
□ I can state that a specialised cell is one that has a specific job in the body
□ I can give 4 examples of specialised cells and can describe some of the special
features they have to help them to do their job
□ I can identify the main parts of the male and female reproductive system and can
describe the function of each
□ I can state that the male sex cell is a sperm cell and a female sex cell is an egg
(ovum)
□ I can state that fertilisation is when the nucleus of a sperm and egg cell fuse to
form a zygote
□ I can state that fertilisation occurs in the oviduct of the female reproductive
system
□ I can state that the embryo develops in the uterus within an amniotic sac which
has fluid to protect it from knocks and bumps
□ I can state that the embryo gains its food and oxygen from its mother via an
organ called the placenta
□ I can state that the embryo gets rid of carbon dioxide and other wastes via the
placenta
□ I can briefly describe the development of an embryo from a fertilised egg
(zygote) to an embryo to a foetus
□ I can name various external agents that may pose a risk to developing embryos
and can describe effects that they can have.
Make sure you have ticked off these learning outcomes
by the end of the topic.
Use the checklist when you are revising for a test or the
S1 exam.
Ask your teacher if you’re unsure about any of the
learning outcomes.
Activity 1 – what’s the common factor????
Collect a set of picture cards from your teacher. Every card has something
in common. In your groups, try to make links between the pictures.
Maybe start with small groups first and then try to decide one thing that
all of the cards have in common. Write your ideas in the space below
Microscope – needed to see cells
Plants, dog, human, micro-organisms – all living organisms
that are made up of cells
Red blood cells – type of cell
Set of instructions – each cell contains a set of instructions for
the functioning of the cell
Robert Hooke and Cork – the discovery of cells
Now watch a short video clip that introduces some interesting
facts and images about cells. They really are amazing! Write
down three things that you are excited to learn about in this
topic.
Various options here:
https://www.glowscience.org.uk/mindmap#!/biology
Cells and the microscope
Every living organism on earth is made up of tiny building blocks called
cells. A cell is the basic unit of life. Cells make up every organ in our
body!
Some organisms are made of only one cell; the human body on the
other hand is made of around 10 trillion cells!!!! But what do they look
like and what do they do?
Use the word bank below to complete the following diagram which
shows how living organisms are organised
Cells
tissue
system
cells
organ
tissue
system
organ
Activity 2 – the structure of living cells
There are two main basic types of cells – animal cells and plant cells.
Each cell is made up of structures that help the cell to do its job.
Look at the labelled diagram on the left of an animal cell. A plant cell
contains all of these structures too – label them on the diagram on the
right and then use page 94 of your textbook to label the three other
structures. Show clearly which cell is animal and plant.
Cell
membrane
Chloroplast
Cytoplasm
Nucleus
cytoplasm
nucleus
__animal__cell
Cell membrane
Cell wall
Vacuole
__plant____cell
Activity 3 – using the microscope
Living cells are so tiny that we need a microscope to see them.
Your teacher will show you an animation which shows just how small a
cell actually is!!
Give some examples of the cells you seen in this animation. You will
be learning much more about these cells in this topic.
A microscope is a very expensive piece of equipment. Your teacher will
show you how to use this properly and there are instructions below–
be careful!!
Use the microscope to look at the prepared slides. Draw a quick
sketch of each in the boxes below.
1.
2.
3.
4.
5.
Ensure you can see the light source by looking through the eyepiece.
Ensure the objective lens is at the lowest magnification
Lower the stage as far as the focusing handle will go
Place the microscope slide on the stage using metal clips.
Look through the eyepiece & carefully turn the focusing handle until the
slide is in focus.
6. Move the revolving turret to the next power and use fine focusing knob if
necessary
Homework 1
Use the wordbank on the left to label the diagram of the microscope
Eyepiece
Mirror
Objective lens
Focusing knob
Focus knob
Eyepiece
Objective lens
Stage
Stage
Mirror/ light source
Each part of a cell has an important job. Use page 94 of your
textbook to complete the table below
Part of Cell
Function
Found in
animal cell?
Found in
plant Cell?
nucleus
Controls the cell
yes
yes
cytoplasm
Site of chemical
reaction
yes
yes
vacuole
Contains cell sap
no
yes
no
yes
yes
yes
no
yes
Provides support to
the cell
Allows substances
Cell
to move in and out
membrane
of the cell
Site of
chloroplasts
photosynthesis
Cell wall
Activity 4 – starter task
As a group, use laminated cards to label the large diagram of plant and
animal cells. Compare your answers with another group and check
them against your completed diagrams on page 5.
Activity 6 – preparing animal and plant cell slides
Earlier in the topic you looked at some animal and plant cells under the microscope.
Before we can look at cells under the microscope they need to be put onto a glass
slide and then have to be stained with a chemical so that we can see the structures
of the cell clearly
Today you are going to learn how to make your own slides
Your teacher will show you how to prepare some slides of animal and plant cells.
Follow the instructions below – work in pairs to do one each. Draw what you see in
the boxes below. Label any of the important parts we learned about in the last
activity clearly.
To prepare cheek cell slides
1. Move the cotton wool bud over the inside of the mouth and along the lower side of
your gum.
2. Smear the cotton bud over a small area of the microscope slide.
3. Place the used cotton bud immediately in the disinfectant provided.
4.
Place 1 drops of the stain methylene blue onto the smear and cover with a cover
slip. Do this over the sink using a staining rack
Hint - Take care not to add too much stain as this will affect your results.
5. Look at your sample under the microscope
6. The cytoplasm will be stained blue and the nucleus should be stained dark blue.
7. After the cells have been observed, immerse the slide and cover slip in a beaker of
disinfectant.
8. Draw what you can see through the microscope. Label the cell membrane, nucleus,
and cytoplasm.
Did you
know…there are
more bacterial cells
than human cells in
the human body!!
To prepare onion cell slides
1. Collect a layer of onion from your teacher.
2. Place onion on slide and add a couple of drops of water
3. Place 1 drop of iodine stain onto the slide
4. Gently lower the cover slip on top to avoid air bubbles (big black circles on slide).
5. Carefully blot off excess liquid with a paper towel.
6. Look through the microscope and draw what you see in the space below, labelling
nucleus, cell membrane, cell wall, vacuole and cytoplasm.
Cheek cell
onion cell
1. Which part of the cell contains the genetic information?
The nucleus
2. Why must cells be stained before we can look at them
underneath the microscope?
To see the structures more clearly (not to see the cells more clearly)
3. Name three parts of a plant cell not shared by an animal cell
Chloroplast, cell wall, vacuole
Activity 7 – starter task
As a small group, use the laminated cards to match up each part of a cell
with its function. Check your answer against your completed table in
activity 4.
Activity 8 – specialised cells
Not all cells look the same. Living organisms are made up of many
different types of cells that do different jobs. Many cells have special
features that allow them to do their jobs well. These are called
specialised cells.
Use the microscopes to look at some slides containing specialised cells
Produce a table in the space below that shows the name of each type of
cell and the special features that it has.
Specialised cell
Red blood cells
Palisade mesophyll
Ciliated epithelium
Sperm
Egg
Nerve cell
Feature
Function
disc shaped/ Red pigment
for carrying oxygen
lots of chloroplasts
for photosynthesis
tiny hairs (cilia)
help sweep mucus away
tail
for swimming
yolky cytoplasm
food store
long extension
carrying nerve impulses
Cartilage – elastic and strong
Rods and cones – sensitive to light
Xylem – lignin to provide support
Root hair – large surface for absorbing water
Bone – flexibility and strength
Homework 2 – specialised cell passports
Your teacher will give you a type of specialised cell to research. Use the
resources suggested below to complete the specialised cell passport.
This will be used to create a class display so they must contain detailed
and accurate information as well as look attractive! Ensure that you
follow all of the criteria below. Use the space below to gather your
information
Information to include
1. Name – what is the cell called
2. Address – Which part of the body does the cell work in? Is it
part of a tissue?
3. Occupation – what job in the body does this cell do? How
does it do this job?
4. Partner cells – names of other cells that they work closely
with to do their job
5. picture or diagram – this should clearly show any special
features that the cell has, e.g shape etc
Suggested resources
http://www.bbc.co.uk/schools/gcsebitesize/science/add_aqa/cells/cells2.shtml
http://www.dr-sanderson.org/specialisedcells.htm
http://www.projectgcse.co.uk/gcse_biology/specialised_cells
Page 96 of science textbook
The information card provided
Did you know…cells
commit suicide when
damaged!
Activity 10 – consolidation activity
You are going to make a 3D model of a cell. Your teacher will provide you with the
materials and instructions. You should ensure that all structures of the cell are
represented and be prepared to talk about your model with others. Your model will be
assessed by other in the class so make it good!
Peer assessment – use the assessment rubric provided by your teacher
to provide a grade and comment to one other group on their model
Did you know…that there
are over 210 different
types of human cells!
The following materials can be used to represent cell parts:
cell wall – Tupperware box
cell membrane – food bag
cytoplasm – wall paper paste/jelly inside food bag
chloroplasts – frozen peas inside jelly/wall paper paste
nucleus- small inflated balloon, bouncy balls inside jelly/wall
paper paste
vacuole – small food bag filled with water inside wall paper
paste/jelly
Activity 11 – consolidation activity
Some cards are repeats of cell passport activity. Others are
additional
Collect a set of cards showing images and words relating to specialised cells. With your
group, match up the words with the images to show:
i)
the name of the cell
ii)
the location of the cell
iii)
the special features each cell has to help it to do it’s job.
Pick 5 of these cells and produce a table to show the above information for each
13
Homework 3 – My journey to the centre of the cell…..
Just imagine if we could shrink ourselves down to be the same
size as cells and we could look inside!
Imagine you can do this and you are visiting a plant cell.
Produce a story that documents your travels to the centre of
the cell. Your story must name all parts of the plant cell that
you have learned about.
The way that you do this is up to you but try to be as
imaginative and creative as you can. You may wish to consider
the following:
- what did you see/feel/touch/smell
- use lots of adjectives (descriptive words)
- could you see the parts doing their jobs? If so what were
they doing?
- try to imagine what it would be like to be actually in the
cell
Your story should be written or typed on no more than 1 piece
of A4 paper and should have some images or pictures.
14
Did you know…the three
things that pregnant woman
dream most about is frogs,
worms and potted plants!
Cells and reproduction
Twig on Glow science vids very good here
Reproduction is the process of making new offspring and is
very important as it enables a species to survive.
Male and female mammals have reproductive organs that work
together as part of the reproductive system. You will have
already learned about these in primary.
Activity 12 – the male and female reproductive system
Demo - Work together as a class to try and label all of the parts
of the male and female reproductive system on the interactive
game.
Now use the wordbank to label each part of the male and
female reproductive systems and complete the tables below
Gland
Scrotum
Sperm
tube
Scrotum
Sperm tube
Testi
Uterus
Uterus/womb
Cervix
gland
Penis
Penis
Oviduct
testi
Vagina
Ovary
Vagina
15
ovary
oviduct
cervix
Name of Structure
Function
Testes/ testi
Production of sperm
Sperm duct/ sperm tube
Carries the sperm to the penis.
Scrotum
A bag of skin which holds the testis
gland
Penis
provides sperm with the energy to
move
Carries the sperm out of the body
Name of Structure
Function
Vagina
Where penis deposits sperm and is the
birth canal
oviduct
Site of fertilisation
Uterus/ womb
Where fertilised egg implants and
develops
cervix
Sits at the neck of the womb
ovary
Production and storage of eggs
16
Activity 13 – sex cells
The ovary and testes are responsible for producing special sex cells that fuse together
during sexual reproduction. These were two of the specialised cells you learned about
in activity 8.
Read the following passage carefully. As you are doing this highlight any key ideas or
words (including the one’s you don’t know the name of).
Then read the passage again and complete the diagrams and table that follows
The sex cells are the cells that fuse together during sexual reproduction to form a
new cell that will eventually form a new organism. The female sex cell is called the
egg or ovum and is produced in the ovary. These round cells are the largest in the
human body. They have a cell membrane, cytoplasm and nucleus. The cytoplasm
contains a rich food store which provides an energy source for the new organism
that will eventually grow. They are visible to the naked eye, being about the size of
the dot at the end of this sentence. Once the female sex glands have matured during
puberty, they normally release not more than one egg per month. Even so, in the
course of a woman's life their total number may very well reach more than 400.
The male sex cell is called sperm. Sperm cells are produced in the male testes. They
are the smallest cells in the human body. While they are invisible to the naked eye,
they can be seen and studied under the microscope. An individual sperm cell has a
certain vague resemblance to a very skinny tadpole, Its total length is about 0.042 mm
(1/600th of an inch). The head, which is only of the length of the sperm, has a nucleus
containing all of the genetic information. Sperm have tails which allow them to swim.
The sperm can move ahead at the rate of 2 cm per minute under favourable
conditions. This movement is essential since the sperm has to reach the egg deep
inside the woman's body. Once the male sex organs have matured during puberty,
they produce millions of sperm cells every day.
17
_animal__cell
_plant__ cell
Cell membrane
tail
cytoplasm
Name of organ in
which produced
size
Special features
nucleus
Sperm
Testes
egg
Ovary
0.042mm
Size of a full stop…
Tail allows them to Largest cell in the
swim 2cm per
human body
minute
Homework 4 – read pages 100 and 101 + questions 1-4
Did you know…most babies are
born with blue eyes and can
change after birth when the
pigment melanin darkens on
exposure to light!
18
Activity 14 – starter task
As a group use the laminated cards to label the large diagram of male and female
reproductive system. Compare your answers with another group and check them
against your completed diagrams on page 16.
Activity 15 - life’s greatest miracle
In order to produce a new organism, the nucleus of the male and female
sex cells must fuse. In many animals, including humans, these cells
come together during sexual intercourse when a man inserts his penis
into a woman’s vagina.
Watch the video that shows the processes involved in
sexual reproduction and then answer the questions that
follow.
1. Where does a male deposit his sperm during sexual intercourse?
vagina
2. Name the process whereby the nucleus of the sperm and egg fuse? Why do you
think it is so important that the nuclei fuse?
Fertilisation- this is where the genetic information is stored – the DNA of the baby
will consist of copies of half of the mothers DNA and half of the fathers. This
information will provide the information for all of the baby’s characteristics.
4. Where in the female reproductive tract does this process happen?
Oviduct/fallopian tube
Did you know… a foetus
acquires fingerprints at 3
months!
5. What name is given to a fertilised egg cell?
zygote
6. Where does the fertilised egg cell implant to continue its development?
Uterus wall
7. Describe what happens to the fertilised egg as it continues its development.
Divides to produce increasing number of cells (ensure that pupils do not think that
cells increase in size)
8. Describe how the female reproductive system prepares itself for a pregnancy
each month
9. How is the foetus protected from knocks and bumps during its development?
The amniotic sac and fluid
19
10. Name the structure that allows the foetus and mother to exchange substances
The placenta
Activity 16 – life’s greatest miracle…mythbuster
Collect a set of cards from your teacher containing various statements
about sexual intercourse and pregnancy. Read through each
statement in your group deciding whether you agree, disagree or are
unsure about each. Create three piles and then compare your
thoughts with another group.
Activity 17 – Askit basket
Hopefully today’s lesson has answered some of your questions about sexual
intercourse and reproduction. If you have any other questions or worries then write
your question on the slip of paper provided and pop it in the basket. This is
anonymous so you do not have to add your name.
Activity 18 - consolidation
Collect a set of cards containing the beginning and ends of sentences about sexual
reproduction, fertilisation and embryonic development. Match them up to make full
sentences. Once your teacher has checked them write the full sentences in the
space below.
20
Activity 19 – the developing embryo
Did you know…a baby’s
teeth start to grow about 6
months before it is born!
It is incredible to think that we all developed from one single cell! The development
of an embryo from a fertilised egg cell to a baby is a complicated and amazing
process!
Watch the video showing the development of an embryo throughout pregnancy
In your small group use the information from the video and the
website below to produce an information card about the stage of
foetal development you have been assigned. Ensure that you follow
the criteria below. This will be used to create a whole class timeline of
development!
Criteria for information card
Your card should contain/show the following information:
1. the period of development in days or weeks
2. the length/size/weight of the foetus at this stage
3. the main developments that take place during this time – any organs formed
,any distinguishable features etc
4. an image showing what the foetus looks like at this time
5. any other interesting/relevant information that you find
Useful websites
 http://www.wpclinic.org/parenting/fetal-development/
 http://www.bbc.co.uk/learningzone/clips/development-of-afoetus/861.html
 www.on101.co.uk/foetal.html
suggested weeks
0-8 weeks
9-16 weeks
17-25 weeks
25 - birth
21
Homework 5
1. Rewrite the following terms into the correct sequence to describe the increasing
number of cells:
New born baby, egg, embryo, zygote, foetus
2. Write a sentence to explain the function of each of the following:
a) the placenta
b) amniotic fluid
c) umbilical cord
d) oviduct
e) uterus
3. How long in total does a foetus take to fully develop?
4. At 2 weeks of development an embryo is made of 1024 cells. At 4 weeks of
development it is made of 4096 cells. What % of the total cells after 4 weeks was
developed at 2 weeks?
5. What was the average weekly increase in the number of cells during the first 4
weeks of development?
6. What is the simple whole number ratio of the number of cells at 2 weeks to the
number at 4 weeks?
7. Label the following diagram using the wordbank provided
, Uterus wall,
Embryo, Amniotic Fluid,
Umbilical cord
22
Activity 20 – starter activity - timeline of life
Collect a card showing a stage of development. Work together
with your classmates to put yourself in the correct order to
show a timeline of life
Activity 21 – factors that affect the development of the embryo
As you have seen the development of the human embryo is a complicated process!
Embryo’s are very vulnerable during these stages and their development can be
seriously affected by many external agents such as chemicals, pathogens and drugs.
You will work in your group to produce a public health campaign in the form of a TV
advert to warn expectant mothers of these risks. In your groups assign the following
roles:
1.
2.
3.
4.
camera operator
researcher
presenter
facilitator
Criteria
Your TV campaign will:
1. Describe the dangers/risks associated with your external agent on a
developing embryo/foetus
2. Give examples of abnormalities that can be caused by this agent
3. Describe the steps that should be taken by an expectant mother to avoid the
dangers posed by this external agent.
23
Extension 1
Look at the following table and draw a bar graph showing how the lining of
the uterus changes during the menstrual cycle
DAY
0
2
4
6
8
10
12
14
16
18
20
22
24
26
THICKNESS OF UTERUS LINING
3.2 mm
2.1mm
1.3mm
1.0mm
1.0mm
1.0mm
1.2mm
1.5mm
1.8mm
2.2mm
2.8mm
3.0mm
3.0mm
3.0mm
Colour the bars for days 0 to 6 in red to show menstruation and 14 to 16
yellow to show ovulation. The remaining bars should be coloured blue.
Write menstruation and ovulation on the graph in the correct places
Sperm can live for 3 days. An egg can live for 2 days. A woman ovulates
between day 12 and day 14. Her fertile period is any time when, as a result of
sex, she could conceive. Can you work out when a woman might be fertile?
Put arrows on your graph to show when a woman is fertile. Say how you
came to your decision
Test your understanding of the cycle by answering the following questions:
a) What is the period of bleeding called?
b) What is the biological name for the uterus lining?
c) What is the release of an egg called?
d) What is the period when fertilisation could take place called?
e) How is day 1 of the cycle marked?
24
Extension 2
The instructions on how to use a microscope have been intentionally messed
up. Sort the following statements into the correct order in your jotter.
A) Lower stage as far as focusing handle will go
B) Place microscope slide on stage using metal clips.
C) Ensure objective lens is at the lowest magnification
D) Ensure the light source by looking through the eyepiece.
E) Look through the eyepiece & carefully turn focusing handle until slide is in focus.
25
Glossary
Word
Cell
Definition
Basic unit of life
Microscope
Piece of apparatus used to magnify cells and small structures
Magnification
The process of enlarging an object in appearance not in physical size
Tissue
A group of cells that work together to perform a specific function
Stain
Chemical applied to cells in order to see their structures more clearly
Cell wall
Provides support to a plant cell
Cell membrane
Allows substances to move in and out of a cell
Vacuole
Found in plant cell only. Contains cell sap and is involved in the movement of
water in and out of cells
Cytoplasm
Site of chemical reactions
Nucleus
Controls all cellular processes – contains the genetic information
Chloroplast
Contains chlorophyll – site of photosynthesis
Specialised cell
Cell that has a specific function and has special structural and functional features
that allow the cell to perform its function
Reproduction
Process of producing offspring
Fertilisation
Fusion of the nuclei of a sperm and egg cell
Testi
Part of male reproductive system that produces sperm
Ovary
Part of female reproductive system that produces eggs
Scrotum
Sac-like structure that contains the testes
Penis
Inserted into the female reproductive tract during intercourse. Releases sperm
during ejaculation
Sperm tube
Carries sperm from the testes to the penis
Vagina
Cervix
Place where penis is inserted during sexual intercourse.
Opening to the womb through which baby is delivered.
26