b2.7 mitosis and meiosis

MitosisWALT: To understand how cells divide by a process called mitosis which results in two daughter cells being produced. WILF: ~ State a definition for mitosis and what is produced as a result. (D)~ Describe how mitosis occurs. (C)~ Explain when mitosis occurs. (B)~ Explain the role of mitosis in asexual reproduction. (A/A*)Keywords

mitosis diploid chromosomes daughter cells asexual

reproduction

In human cells, you will find 46 chromosomes (23 pairs) Diploid number

To make more body cells, these cells must divide, a process called mitosis.

Parent cell

Daughter cells

Why?

For growth

For repair

Mitosis and cancer

Keywords

NucleusChromosomesDiploidDNA replicationParent cellDaughter cell

Questions1.What is a diploid cell

and how many chromosomes does a human diploid cell have?

2.Explain why mitosis must occur.

3.Define asexual reproduction and name examples of when this happens.

MeiosisWALT: To understand how sex cells (gametes) are produced by another type of cell division, meiosis. WILF: ~ State a definition for meiosis and gametes. (D)~ Describe how meiosis occurs. (C)~ Explain differences between mitosis and meiosis. (B)~ Explain the importance of meiosis in relation to variation. (A/A*)

Keywords

meiosis haploid gametes sexual reproduction

variation

Gametes (Sex cells)egg cell

sperm cell

diploid cell

haploid cells

zygote

Sexual reproduction requires sex cells, also known as…

These cells are different to body cells because…

When gametes fuse during fertilisation, they produce a…Keywords

GametesHaploidZygote

MeiosisTo produce gametes, a different type of cell division must happen, meiosis.

1st cell division-separates the pair of chromosomes.

2nd cell division-separates the copies of each chromosome.

Making gametes-Meiosis

1. You start off with a ___________ cell, which contains pairs of _____________.

2. The chromosomes then _____________ (like they do in mitosis).

3. The __________ cell ___________ now happens, the pairs of chromosomes separate.

4. The second cell division then happens. This produces ____ ____________ cells. Each cell gets a copy of one chromosome from each pair.

These 4 cells are known as being _________, as they have half the amount of chromosomes.This type of cell division is known as ___________.

KeywordsChromosomesReplicateMeiosisHaploidDiploidFirst4DivisionDaughter

Making gametes-Meiosis

1. You start off with a ___________ cell, which contains pairs of _____________.

2. The chromosomes then _____________ (like they do in mitosis).

3. The __________ cell ___________ now happens, the pairs of chromosomes separate.

4. The second cell division then happens. This produces ____ ____________ cells. Each cell gets a copy of one chromosome from each pair.

These 4 cells are known as being _________, as they have half the amount of chromosomes.This type of cell division is known as ___________.

KeywordsChromosomesReplicateMeiosisHaploidDiploidFirst4DivisionDaughter

Mitosis vs. meiosis

Mitosis Meiosis

No. of cell divisions?

No. of daughter cells formed?

Diploid or haploid cells produced?

Needed for…?

Daughter cells identical?

Use your notes on mitosis and meiosis to fill in this table of differences between the two processes.

Mitosis Meiosis

No. of cell divisions?

No. of daughter cells formed?

Diploid or haploid cells produced?

Needed for…?

Daughter cells identical?

Mitosis Meiosis

No. of cell divisions?

No. of daughter cells formed?

Diploid or haploid cells produced?

Needed for…?

Daughter cells identical?

Mitosis Meiosis

No. of cell divisions?

No. of daughter cells formed?

Diploid or haploid cells produced?

Needed for…?

Daughter cells identical?

Mitosis Meiosis

No. of cell divisions?

No. of daughter cells formed?

Diploid or haploid cells produced?

Needed for…?

Daughter cells identical?

Mitosis Meiosis

No. of cell divisions?

1

No. of daughter cells formed?

4

Diploid or haploid cells produced?

haploid

Needed for…? Producing gametes (sex cells).

Daughter cells identical?

Yes

Mitosis Meiosis

No. of cell divisions?

1

No. of daughter cells formed?

4

Diploid or haploid cells produced?

haploid

Needed for…? Producing gametes (sex cells).

Daughter cells identical?

Yes

Mitosis Meiosis

No. of cell divisions?

1

No. of daughter cells formed?

4

Diploid or haploid cells produced?

haploid

Needed for…? Producing gametes (sex cells).

Daughter cells identical?

Yes

Mitosis Meiosis

No. of cell divisions?

1

No. of daughter cells formed?

4

Diploid or haploid cells produced?

haploid

Needed for…? Producing gametes (sex cells).

Daughter cells identical?

Yes