1. Sexual Reproduction
&
Inheritance

2. Now lets meet their children!
Starter: Characteristics from sexual reproduction leading to variation
Characteristics
Meet our Mr Men
And our Little Misses
Now lets meet their children!

3. Starter: Characteristics from sexual reproduction leading to variation

4. Objective Success Criteria
To investigate how sexual reproduction can lead to variation within a species.
Success Criteria
By the end of the lesson I:
can identify the two types of reproduction as sexual and asexual reproduction.
can explain the differences between sexual and asexual reproduction in that sexual reproduction leads to variation because the genes from two parents are mixed to create a new individual whereas in asexual reproduction there is only one parent and hence no mixing.
can explain in detail how sexual reproduction leads to variation within a species using the correct scientific key words.

5. Where do chromosomes come from?
STARTER
In most cells chromosomes are matched in pairs based on their size and shape.
Where do chromosomes come from?
Each pair of chromosomes contains one chromosome that has been inherited from each parent.
chromosome from male parent
chromosome from female parent

6. What’s in your genes?
Inside the NUCLEUS of every one of your cells there are CHROMOSOMES.
CHROMOSOMES are coiled up DNA strands.
On each CHROMOSOME there are several thousand GENES.
GENES are shorter sections of DNA that code for particular CHARACTERISTICS
GENES provide instructions to make PROTEINS that control the functions of the cell and therefore determining how the body functions (characteristics)

7. Asexual Reproduction
Asexual reproduction only involves 1 parent and so gives rise to offspring known as CLONES. Why?
Daffodils can reproduce both Asexually and Sexually! Why would this make these plants more successful? Explain the differences between the two types of offspring?

8. Sexual Reproduction All living things can reproduce.
In most animals and plants this usually happens by sexual reproduction.
This is when a male and a female mate, and produce offspring using sex cells.
The young plants or animals will have similar characteristics to their parents but will not be identical to them.

9. Sexual reproduction involves special sex cells called gametes.
Male animals produce gametes called sperm cells and female animals make gametes called egg cells.
Who's related?

10. Draw and label sex organs in plants
In plants, the female sex cells are also called egg cells; the male sex cells are found in pollen grains in the anthers.

11. What is the difference between Pollination and fertilisation
Pollination is ………………..
Fertilisation is …………………..

12. Variation Why is variation important ???
Whole population will not be wiped out
Increase genes in a population
Allow survival of the fittest

13. Sexual reproduction is VERY risky as it relies on the joining of two sex cells. Even so, sexual reproduction is SO important for variation amongst species and hence survival that it can be seen in almost all types of plants and animals
THINK
If one parent has blue eyes and one parent has brown eyes what colour eyes will their children have?
Can you prove this?

14. ?
What the...

15. Each pair of genes affects a different characteristic
Each gene can have a different form. The versions of the same gene are called ALLELES
Each parent will have two chromosomes that contain the gene for eye colour.
Gene for eye colour
How can we represent the different eye colours?
Blue eyes
Brown eyes

16. I can explain how sexual reproduction leads to variation
Different versions of the same gene are known as ALLELES.
For example, blue and brown are two alleles for eye colour.
If we inherit one chromosome from each parent what ALLELES will the offspring have?

17. I can explain how sexual reproduction leads to variation
The Brown allele is DOMINANT over the blue allele.
What colour eyes will the offspring have?
All the offspring will have Brown eyes
Some alleles are DOMINANT over other forms of the gene.
This means that the DOMINANT allele will always be expressed (shown) over the RECCESSIVE allele.
What does this mean?

18. I can explain how sexual reproduction leads to variation
Punnett Squares B B
Alleles
Brown = B
Blue = b
Genotype
Homozygous Brown = BB
Homozygous Blue= bb b b
What does HOMOZYGOUS mean?

19. I can explain how sexual reproduction leads to variation
Can two people with brown eyes have blue eyed children?
Genotype
Brown = Bb
Homozygous or heterozygous?

20. I can explain how sexual reproduction leads to variation
PHENOTYPE means the physical expression of the gene.
i.e. what colour the eyes will be
GENOTYPE is the pair of alleles for a characteristic
i.e. BB or Bb or bb

21. I can explain how sexual reproduction leads to variation

22. There are genes that decide whether;
INVESTIGATION
There are genes that decide whether;
your earlobes are attached close to the side of your head or hang freely
your thumb is straight or curved
you have dimples when you smile
you have hair on the second segment of your ring finger
You are going to complete an investigation on babies lobes!
HANG FREELY
STRAIGHT
ATTACHED
CURVED

23. PLENARY
In most cells chromosomes are matched in pairs based on their size and shape.
Recap
How many chromosomes?
How many pairs?
Where are they found?

24. Objective Success Criteria
To investigate how sexual reproduction can lead to variation within a species.
Success Criteria
By the end of the lesson I:
can identify the two types of reproduction as sexual and asexual reproduction.
can explain the differences between sexual and asexual reproduction in that sexual reproduction leads to variation because the genes from two parents are mixed to create a new individual whereas in asexual reproduction there is only one parent and hence no mixing.
can explain in detail how sexual reproduction leads to variation within a species using the correct scientific key words.