Genetics Buzzwords

the set of genes (alleles) that an organism possesses

physical appearance of an organism.

when two alleles (gene types) are identical

when the two alleles are different

different forms of the same gene

allele which controls the characteristic whenever it is present.

allele whose characteristics only show up when it is present on both chromosomes

BB or Bb

bb

Determining characteristicsIn pea plants, tallness (T) is dominant to dwarfness (t)

A tall pea plant could have a genotype of:

TTTt

Both combinations have the same phenotype- tall.

A dwarf pea plant could only have the genotype tt Phenotype- dwarf.

homozygous dominant

heterozygous

homozygous recessive

Gene combinationsThe simplest genetic cross involves one characteristic and is called a monohybrid cross.

In this the parents (P) are crossed (bred) with each other, and the offspring (F1 generation) observed and counted.

Follow the procedure on the board!!

This explains how the sex of a child is determined by X and Y chromosomes.

gametes

This can also be shown and combinations worked out using a Punnett square:

X X

X XX XX

Y XY XY

Mother

XX

X X

Father

XY

X Y

Offspring: Male or female?

XX XY XX XY

F FM M

1:1 ratio male to female offspring

Task

1. Complete the problems in the Monohybrid Crosses booklet

• DO NOT SKIP STEPS!!

• Always define the alleles

• Always draw the Punnet square

2. Let´s play Traits Bingo! (15 min)

Keywords review

• Can you match up the key words to the definitions?

• You only have 4 min before the bomb goes off!

STARTER: Get your brains in gear!NO NOTES!!!

A – normal skin pigmentationa – albino

What percentage chance is there of producing a child with albinism?

Tasks this lesson

1: Finish the Monohybrid Crosses revision booklet (15 min)

2: Try the problems in the More Monohybrid crosses booklet! (20 min)

3: Let’s play Traits bingo! (15 min)

STARTER1. Who is known as “the man of 1000 peas?”

2. How long has he been running his experiments for?

3. How many plants did he grow?

4. What did he notice when he first grew pea plants?

5. What field of biology has come about because of his experimenting on peas?

Tasks this lesson

1. Finish the More Monohybrid Crosses booklet2. Attempt the past paper questions (put the theory into practice!)3. Finish the lyrics!

Tasks this lesson

1. Have a go at the past paper question booklet 2. Read the Mendel´s Laws booklet and answer the questions3. The genetics of skin colour TED talk