1. Inheritance and evolution

2. Pre Assessment
Label the parts of the below given image.

3. Cell
The structural, functional and biological unit of all organisms.

4. Nucleus The nucleus is a membrane bound structure
Contains the cell's hereditary information
Controls the cell's growth and reproduction.

5. DNA-Deoxyribonucleic Acid

6. Location of DNA

8. DNA It is a nucleic acid containing the genetic instructions
It is used in the development and functioning of all known living organisms

10. There are 46 chromosomes in every cell-23 from female parent and 23 from male parent.

11. Chromosomes
A chromosome is an organized structure of DNA and protein found in cells.

13. Genes
The DNA segments carrying this genetic information are called genes.
A unit of heredity of all living organisms.
It codes for a specific protein

14. Video on Genes

15. Why are you unique?

16. Inheritance
What we are like depends on the genes we inherit from our parents
The study of inheriting characteristics is called genetics

17. The same but different !
Variation

18. Student activity
Write down similarities and differences between you and your pet.
Now get into pairs and write down the similarities and differences between you and your partner.

19. What is Variation?
Individuals within a species have different characteristics
Variation ensures survival

20. Types of variations Continuous vs. Discontinuous
Continuous Variation
- Small differences between individuals that varies over a range.
- Mostly caused by environment.
- e.g. height, shoe size, length of hair
- Bell shaped graph
Discontinuous Variation
- Differences that are classed or categorised
- Always caused by genes.
- e.g. blood group, sex, hair colour, eye colour
- Bar graph

21. Types of variation
Intra specific variations
Inter specific variations
Differences between organisms belonging to different species/ group .
Eg: Differences between a water lily and a cat.
Differences between organisms belonging to the same group/ species
Eg: differences between a boy and a girl

22. Discontinuous and Continuous Variation
Number of
people
Hair colour
only a few options
Height
varies over a continuous
range

23. What causes Variation? Variation can come about for two reasons:
Some features can be inherited. That means that you get them from your parents
Other features are affected by the environment ( acquired).
Lots of features are a combination
of both
Examples?

24. Environmental Variation
Causes:
climate, diet, lifestyle, culture, accidents
Environment affects how our inherited characteristics develop
Twins who grow up separately might become very different:
e.g. fashion, taste, hair colour, build, personality, aptitudes

25. Genetic Variation Causes:
- Mixing of parent information during meiosis
- Gamete forms from a unique combination of genetic information
Siblings can have both similar and very different traits
They are mixtures of their parents, each sibling can receive different characteristics of their parents
e.g. natural hair colour, eye colour, blood type

26. Get into groups and discuss whether these features are Inherited, environmental or both?
Example
Cause
Sex
Weight
Height
Dyed blonde hair
Strength
Beard
Cut on face
Intelligence
Got a bad cold
Blood group
Eye colour

27. TASK:-
Read Pg. No from your text book and ans ques no 1-4 on pg no 143.

28. Identify the similarities and differences among the members of this family !
Look at the picture and identify 5
similarities between the parents and the children.

29. Video on Variation http://www.youtube.com/watch?v=B_PQ8qYtUL0
- info on variation

30. Gregor Mendel

31. Identified “genes” and called it as Inherited traits.
Father of Genetics

32. Homozygous and heterozygous Types of Gene
Today’s Objective
Homozygous and heterozygous
Types of Gene
Dominant Gene
Recessive Gene
Genotype and Phenotype

34. Human Chromosomes

35. Homozygous - two alleles the same
Heterozygous - two different alleles

36. Types Of Genes

37. Genes Dominant gene Recessive Gene They are ‘stronger’
and expressed
They are ‘weaker’
and not expressed
They are written as capital letters -‘B’
They are written as small letters -‘b’

38. Brown eyes are dominant than blue eyesbb BB
Rabbits black fur is dominant than white fur bb BB

39. Genotype and Phenotype

40. So what is Phenotype and Genotype??

41. Phenotype
The physical appearance of individuals within a species is termed as the Phenotype.

42. Genotype
The different genes that each individual has is their genotype

43. B + b = Bb b + b = bb B + B =BB Genotype BB Genotype - Bb
Phenotype - Black fur
B + b = Bb
b + b = bb
Genotype - Bb
Phenotype - Black fur
Phenotype - White fur
Genotype - bb

44. MONOHYBRID CROSSES
Things to know before attempting to solve a monohybrid cross:-

45. Monohybrid worksheet posted on the Bio website.

46. Mutations: a source of variation

47. Mutations are the source of variation
A mutation is a heritable change in genetic material.
Addition or deletion of the certain codes in the genes can lead to mutations.
Major Causes
Diet
Lifestyle
Radiation
Chemicals
Stress

49. DISCLAIMER – The following Picture might be disturbing for some.

50. THE TREE MAN

51. How can Mutation be a source of evolution??

52. Natural Selection
The competition between the individuals for food, space, resources, environment led to the struggle for survival
The individuals that can compete successfully for the resources are most likely to survive
This is known as survival of the fittest and also known as natural selection.

53. Mutation:- http://www. bbc. co
Mutation:- Natural selection

54. Read the articles in the given sites and answer the questions below, in your C.W.
Name a disease that is an example of an inherited disorder. Explain how it came into being.
‘Individuals that are poorly adated to their environment are less likely to survive and reproduce’ –Explain this statement.