LO:
• Describe what a chromosome is and where chromosomes are
found in the cell.
• Describe simply how and why body cells divide.
• Draw simple diagrams to describe mitosis.
• Draw a simple diagram to describe the cell cycle
keywords: mitosis, daughter cell, interphase, cytokinesis.
Starter: Draw and label
the animal cell.
Write down the structure
of each organelle.
Think-pair-share: Have you inherited any characteristics from your
parents?
David Beckham and his sons
The genetic information of all organisms is contained in the nucleus, in
chromosomes, made of DNA. The DNA in resting cells is found in the
nucleus as long, thin strands. For cell division, these strands form
condensed chromosomes.
Human body cells have 46 chromosomes, or 23 pairs. Each chromosome
in a pair has the same type of genes along its length. One set of 23
chromosomes is inherited from the biological mother (from the egg),
and the other set is inherited from the biological father (from the
sperm).
Where is genetic information in
human body cells?
How many chromosomes are there
in a human body cells?
A karyotype shows the full set of
chromosomes of an individual
arranged in sequence.
How are the chromosomes arranged in a
karyotype?
In pairs, in order of decreasing size.
The sex chromosomes are displayed last.
A gene is a section of DNA, which carries coding for a particular
protein. Different genes control the development of different
characteristics of an organism. Many genes are needed to carry all the
genetic information for a whole organism.
What is the job of genes?
Genes, DNA and chromosomes
introduction video
The number of genes and chromosomes varies from species to
species. For example, cells in human beings have 46 chromosomes
that carry about 30,000 genes in each cell; and cells in fruit flies
have 8 chromosomes that carry about 13,600 genes.
LO:
• Describe what a chromosome is and where chromosomes are
found in the cell.
• Describe simply how and why body cells divide.
• Draw simple diagrams to describe mitosis.
• Draw a simple diagram to describe the cell cycle
keywords: mitosis, daughter cell, interphase, cytokinesis.
Cells divide to produce two new ones which are exact copies of the
original cell. This type of cell division is called mitosis. Two daughter
cells are produced from the parent cell. Each daughter cell has 46
chromosomes. All body cells divide by the process of mitosis. The only
cells in the human body that do not undergo mitosis are the gametes, or
sex cells (egg and sperm) which undergo a different process called
meiosis.
During mitosis, the double chromosomes are pulled apart as each new
set of 46 chromosomes moves to opposite ends of the cell. Two nuclei
then form. The cytoplasm and cell membrane then divides and two
identical cells are produced.
Using the
mitosis
worksheet draw
the steps of
mitosis
Mitosis video
The way to try and remember the job of mitosis:
Link t= two identical daughter cells
Remember mitosis produces two daughter cells from the parent
cell with the same chromosomes (46).
(a) (i) mitosis
correct spelling only
1
(ii) replicates / doubles / is copied / duplicates
accept cloned
ignore multiplied / reproduced
1
LO:
• Describe what a chromosome is and where chromosomes are
found in the cell.
• Describe simply how and why body cells divide.
• Draw simple diagrams to describe mitosis.
• Draw a simple diagram to describe the cell cycle
keywords: mitosis, daughter cell, interphase, cytokinesis.
A cell that is actively dividing goes through a series of stages called the
cell cycle. The cycle involves the growth of the cell and the production
of new cell components and division for growth, repairing tissue and
replacing cells. The cell cycle has 3 main phases: interphase, mitosis and
cytokinesis
What is the
function of a
cell cycle?
Cell cycle video
The cell grows. The number of sub-cellular structures such as
mitochondria and ribosomes increases.
The DNA replicates to form two copies of each chromosome.
Further growth occurs and the DNA is checked for errors and any
repairs made.
Mitosis – the chromosomes move apart and the nucleus divides. The
genetic material splits into two.
The cytoplasm divides into two and the new cell membrane separates
off to give two new, identical cells (daughter cells).
1.
2.
3.
4.
5.
6.
The cell grows. The number of sub-cellular structures, e.g.
mitochondria and ribosomes, increases.
The DNA replicates - to form two copies of each chromosome.
Further growth occurs and the DNA is checked for errors and any
repairs made.
Mitosis – the chromosomes move apart and two nuclei form.
The cytoplasm divides into two and the new cell membrane
separates off to give two new, identical cells (daughter cells).
Temporary cell resting period, or the cell no longer divides, e.g. a
nerve cell.
Complete cell cycle worksheet.
Mitosis occurs rapidly in a newly formed fertilised
egg. Suggest another situation in the body where
you might expect cells to be actively dividing by
mitosis.
Mitosis occurs rapidly in a newly formed fertilised egg. Suggest
another situation in the body where you might expect cells to be
actively dividing by mitosis.
Mitosis is also needed for repair and replacement of cells at site of
wound or injury, during growth spurts, during production of red blood
cells in bone marrow (happens all the time).
LO:
• Describe what a chromosome is and where chromosomes are
found in the cell.
• Describe simply how and why body cells divide.
• Draw simple diagrams to describe mitosis.
• Draw a simple diagram to describe the cell cycle
keywords: mitosis, stem cells, daughter cell, interphase,
cytokinesis.
True or False?
1) All cells divide by mitosis. F- sex cells undergo meiosis
2) Mitosis – the chromosomes move apart and two nuclei form. The
genetic material splits into two. T
3) Cells need to divide in order to grow and be replaced when
damaged. T
4) The daughter cells have half number of chromosomes as the
parent cell. F – daughter cells have the same number of
chromosomes as the parent cell
5) Cytokinesis is when the cytoplasm divides into two and the new cell
membrane separates off to give two new, identical cells (daughter
cells). T
6) A gene is a section of DNA, which carries coding for a particular
protein. Different proteins control the development of different
characteristics of an organism F – Different genes control
Complete Chromosomes and Mitosis worksheet.
LO:
• Describe what a chromosome is and where chromosomes are
found in the cell.
• Describe simply how and why body cells divide.
• Draw simple diagrams to describe mitosis.
• Draw a simple diagram to describe the cell cycle
keywords: mitosis, daughter cell, interphase, cytokinesis.
From 0-10 write down how confident you feel about Chromosomes
and Mitosis and write down what you need to do to increase your
score.
0 = Not feeling confident
10 = I feel confident