Mrs. Baxter and Mrs. Herndon

5th Life Science

Bill Nye Genetics Video

Genetics

1. Genetics is the study of genes, heredity, and genetic variation in living organisms. 

https://genetics of a four leaf clover

2. DNA (Deoxyribonucleic Acid) - carries the genetic information for a cell and is a set of instructions that tells the cell what to do or be.

3. Chromosome – a single long molecule of DNA (x shape).

https://brain pop DNA/

4. Gene – a part of the chromosome that contains DNA

Traits:

What are traits?

1. Traits are characteristics we

inherit from your parents.

2. The environment we grow up

and live in also helps define our

traits. For example: exposure to

chemicals or sunlight can change hair color

Genetic traits

5. Inherited trait – a characteristic passed from parents to their offspring. 6. Dominate trait – a strong trait that appears even if the organisms has only one factor. 7. Recessive trait – a trait that appears only if an organism has two factors. 8. Hidden trait – a trait that an organism carries, but is not expressed.

Dominant vs. Recessive Traits●9. Allele - one of a pair of genes that control a trait, such as blood type or colorblindness.

●Alleles are different “flavors of genes”●They will be either dominant or recessive traits

●There will always be 1 allele from the Mother and 1 allele from the Father

●a diagram called the Punnett Square●Punnett Square Video

More say of the outcome of that trait

No say unless there are 2 recessive alleles

What is Heredity?

10. Heredity - the passing on

of traits from parents to a child

We inherit traits from our parents

1. What traits have your inherited from your parents?

2. Why do brothers and sisters resemble each other?

DNA (“De-oxy-ribo-nucleic” Acid)Chemical code Master copy of instructions

for cell structure and function

Give us our traits like hair color, eye color, height, personality, & talents

Each gene makes proteins (building blocks for everything in your body)

DNA (“De-oxy-ribo-nucleic” Acid)Structure (what it looks

like) Three dimensional helix

Spiral staircase or

twisted ladder

Humans have 46 pairs

of chromosomes (or 23

pairs)

Half from one parent &

half from another parent

DNA Structure Cross pieces, “rungs” are

made of nitrogen base pairs

Same two bases always pair together:

adenine (A) & thymine (T)

cytosine (C) & guanine (G) The matching of the base

pairs, (A with T) and (C with G), provides a way for exact copies of DNA to be made called DNA replication.

DNA Mutation - Damaged chromosomes

- Mismatched base pairs

DNA Mutation - Mistakes in the DNA

- Example: albinism

DNA Discovery/History (1950-1960’s) - Rosalind Franklin 1st to

x-ray DNA

DNA X-rayRosalind Franklin

DNA Discovery/History (1950-1960’s) Maurice Wilkins gives Rosalind

Franklin’s x-rays to James Watson and Francis Crick

Crick and Watson make the 1st model of DNA

Rosalind Franklin dies of cancer

Wilkins, Watson, and Crick share a Nobel Prize for the DNA model

DNA Model

DNA Discovery/History (1950-1960’s)Maurice Wilkins

James Watson and Francis Crick

DNA Model Sketch