Genetics

SB3: Genetics

(𝑡𝑎𝑦𝑙𝑜𝑟'𝑠 𝑣𝑒𝑟𝑠𝑖𝑜𝑛)

Mendel, Alleles, Inheritance

Esto es un párrafo listo para contener creatividad, experiencias e historias geniales.

What are we going to learn?

Mendel

Mendel's Laws of Inheritance

Alleles

Genetic Diagrams

The Pea Plant Punnet Square

How Sex is Determined in Humans

The Pea Plant Experiment

Alleles

Mendel

Mendel's Laws of Inheritance

Genetic Diagrams

Inheritance: Punnet Squares

Inheritance: Punnet Squares

Six Mark Question

Gregor Johann Mendel

The Father of Genetics(1822-1884)

Austrian monk Gregor Mendel observed how plant traits were handed down from one generation to the next while tending to his garden plot at the monastery in the middle of the 19th century. Mendel's discovery of the laws determining the inheritance of traits forms the basis of modern genetic research.

Info

The Pea Plant Experiment

Breeding pea plants is as easy as one, two three

Two of the tall pea plant from the 1st set of offspring are crossed

A tall pea plant and a dwarf pea plant are first crossed

Dwarf Pea Plant

Tall Pea Plant

Tall Pea Plant

Dwarf Pea Plant

Tall Pea Plant

Tall Pea Plant

Tall Pea Plants : Dwarf Pea Plants 3 : 1

All Tall Pea Plant Offspring

Mendel's Laws Of Inheritance

No rules in breakable heaven

Law 1

Law 3

Law 2

One 'hereditary unit' from each parent is passed on to the offsprings.

Traits are determined by "hereditary units" and these hereditary units are passed unchanged from parent to offspring.

Hereditary units can be dominant or recessive.

No Guts, No Glory

It took a while for people to understand his work...

Reasons to feel sorry for Mendel 1

Reasons to feel sorry for Mendel 3

Reasons to feel sorry for Mendel 2

Scientists at the time did not have the knowledge to properly understand Mendel's discoveries. They knew nothing about genes, DNA, and chromosomes..

Although groundbreaking, his work was new to the scientists of the time.

After his death, people realized the importance of his work.

Alleles

Key Definitions

• Alleles: Different versions of the same gene.
• Genotype: The combination of alleles responsible for determining each trait.

• Phenotype: The physical appearance of a genotype e.g. eye colour, hair colour.
• Homozygous: Both alleles are the same, e.g. AA, aa
• Heterozygous: The two alleles are different; Aa
• Gene: a little region of DNA on a chromosome that specifies the amino acid sequence needed to produce a particular protein. It can be copied and passed on to the following generation; it is the unit of heredity.

Genetic Diagrams

Example-Cystic Fibrosis

Unaffected but carrier

Unaffected but carrier

FF

ff

Carrier

Carrier

Unaffected

Has CF 25%

Inheritance: Punnet Squares

The Pea Plant Punnet Square

The T is the allele inherited from the Tall Pea Plant (dominant). The t is the allele inherited from the Dwarf Pea Plant (recessive). The offspring with the TT or Tt alleles, will be tall as only the dominant (T) allele will be expressed. The tt has no dominant allele (only recessive alleles will be expressed)-so the pea plant will be a dwarf pea plant. So the ratio for Tall: Dwarf will be 3:1

TT

Tt

tt

Tt

Inheritance: Punnet Squares

Determing the sex of the child

XX

XX

XY

XY

Father

Mother

Offspring will be a Female: 50%Offspring will be a Male: 50% Female:Male 1:1

Six MarkQuestion

ANSWER

Figure 16 shows a drosophila fruit fly.

The brown body colour of a drosophila fruit fly is dominant to black body colour and is not sex-linked. Explain how Gregor Mendel could have used a brown drosophila fruit fly and a black drosophila fruit fly to show that brown body colour is dominant to black body colour.

THANK YOU!

HAPPINESS IS A BUTTERFLY

AND MAKE SURE YOU WATCH THE ERAS TOUR

Esto es un párrafo listo para contener creatividad, experiencias e historias geniales.