1. Genetics and heredity

Topic 1: GENETICS

GENETICSWhat do we know?

WHAT’S GOING ON?

Topic 1: Genetics

Genetics is the study of genes, heredity and variation in living organisms. Genes hold the information to build and maintain an organism (living thing). ‘Gen’ is Latin for ‘beginning’, because genes are the beginning of how living things are created.

So where are our genes anyway??

Google: “AMNH Ology”Click “Genetics” as your Ology on the LHS scroll barScroll down to “Explore the Evidence: What makes you YOU? What makes me ME?” (Bottom RHS)

Topic 1: Genetics

Genetics is the study of genes, heredity and variation in living organisms. Genes hold the information to build and maintain an organism (living thing). ‘Gen’ is Latin for ‘beginning’, because genes are the beginning of how living things are created.

See next page

• Divide a double page into 6 and draw a series of diagrams that shows where our genes are situated.

• Title: Where are my genes?

Organism

Cell

Nucleus Chromosome

Gene

DNA

Box 1: “Me”/Organism

All organisms (living things) are made up of cells.

Humans are made up of billions of microscopic cells. Some organisms are only made of one cell.

Box 2: Cells

Cells are the building blocks of life. There are many different types of cells. E.g. Humans have: skin cells, muscle cells, red blood cells, sex cells and more.Plants have: Photosynthetic cells, stem cells, root cells and more.

Box 3: Nucleus

Inside each cell is a nucleus. The nucleus is the control center of each cell. This is because it contains genetic material (DNA) which is a code for telling the cell what to do.

Box 4: Chromosomes

Chromosomes are long thread-like strands of DNA found in the nuclei of cells.

Humans have 23 pairs of chromosomes (46 in total). One set of chromosomes comes from mum, and one set comes from dad.

Box 5: Genes

Genes are segments of chromosomes (that is a sequence of DNA). A gene controls a particular characteristic of an organism. E.g. Eye colour

Box 6: DNADNA or Deoxyribonucleic Acid makes up the genetic instructions used in the development and functioning of all organisms. DNA is made up of 4 bases: A, T, C and G. The order and number of these bases spell out the genetic code. Differences in the order of these bases between individual organisms of the same species result in differences in genes. E.g. Brown. Blue, Green or grey eyes.

Cell clip

• http://www.youtube.com/watch?v=eOvMNOMRRm8&feature=related

How many genes do we have?

Organism Number of genes

Human

Drosophila Fruit Fly

Yeast

How similar are we to other living things?Organism DNA Similarity to humans

Chimpanzee

Drosophila Fruit Fly

Roundworm

Bacteria

Traits

• Brainstorm a list of traits you think you have received from your parents. – Traits are not just physical characteristics, they can

also be connected to your behaviour (e.g. dog breeds), intelligence, health (e.g. allergies, good/bad health) interests and personality.

– Remember, a lot of who you are is not only determined by your genes, but by the environment you are growing up in. E.g. hair colour, intelligence.

8F’s traits

• Worksheet of 10 traits

8F’s traits

1 2 3 4 5 6 7 8 9 100

2

4

6

8

10

12

14

16

Trait ATrait B

Heredity: how our traits are determinedHeredity is the passing of traits from parents to their offspring. Humans have two sets of 23 chromosomes (23 pairs, which = 46 in total)

When parents conceive a child, they each contribute one complete set to the child, this way, both parents pass genes on to the child.

http://www.youtube.com/watch?v=jHWJqzlHl3w&feature=related