Lesson 8
Egg cells, sperm cells and fertilisation
Recap Questions -
Last lesson
Cells and Microscopes
Success Criteria – What you will learn in this lesson
Egg cell and sperm cells are examples of animal cells.
They have half the number of chromosomes of normal cells.
(23 in humans)
Fertilisation is the joining of the egg and the sperm to form a zygote
(fertilised egg). In humans the zygote will have 46 chromosomes.
23+23 =46.
Where and how fertilisation occurs.
Animal Cell
Recap
Animal Cell
Recap
Egg and Sperm
Egg and Sperm
Human Fertilisation Clip – 7 mins
http://www.bbc.co.uk/learningzone/clips/humanfertilisation/12227.html
Fertilisation
Fertilisation
On the following slide the second half of the sentences
with a blue background are mixed up. Rearrange the
second half to fit with the correct first half.
1
Fertilisation is the joining together
to stop other sperms from entering.
2
The sperms swim through the cervix,
up the uterus
of a sperm and an egg.
3
This is a very long way for sperms to
swim
and a sperm can live for up to 3 days.
4
To overcome these losses millions of
sperms
when it is possible for the egg to be
fertilised.
5
A number of sperms may reach the
egg
and most of them will not reach the egg.
6
This is because the egg makes a skin
around itself
are released into the vagina at once.
7
The egg can live for about a day
and into the fallopian tube to find the egg.
8
So there are only about 3 days in a
month
But only one is able to enter it.
Answers
1
Fertilisation is the joining together
of a sperm and an egg.
2
The sperms swim through the cervix,
up the uterus
and into the fallopian tube to find the egg.
3
This is a very long way for sperms to
swim
and most of them will not reach the egg.
4
To overcome these losses millions of
sperms
are released into the vagina at once.
5
A number of sperms may reach the
egg
but only one is able to enter it.
6
This is because the egg makes a skin
around itself
to stop other sperms from entering.
7
The egg can live for about a day
and a sperm can live for up to 3 days.
8
So there are only about 3 days in a
month
when it is possible for the egg to be
fertilised.
1
Fertilisation is the joining together
of a sperm and an egg.
2
The sperms swim through the cervix,
up the uterus
and into the fallopian tube to find the egg.
3
This is a very long way for sperms to
swim
and most of them will not reach the egg.
4
To overcome these losses millions of
sperms
are released into the vagina at once.
5
A number of sperms may reach the
egg
but only one is able to enter it.
6
This is because the egg makes a skin
around itself
to stop other sperms from entering.
7
The egg can live for about a day
and a sperm can live for up to 3 days.
8
So there are only about 3 days in a
month
when it is possible for the egg to be
fertilised.
Revision of reproductive system if required
Female reproductive system
Oviduct/
fallopian tube
Male reproductive system
Sperm duct
Gland
Penis
Testis
scrotum
Reproductive organs
1
4
5
2
6
7
3
8
9
Male reproductive organs
Female reproductive organs
Homework due: 00/00/0000
• Starting Science worksheet of reproductive system to label and stick into
jotter