Genetics KWLKWL

What makes you…you? How do you get your DNA? Your DNA! Heredity: the passing of physical characteristics from parents to offspring Genetics: study of heredity

Deoxyribonucleic Acid It is in the shape of a Double helix = twisted ladder DNA stands for…

DNA is your genetic code 4 nitrogen bases make up your “genetic alphabet”. –A = adenine –T = thymine –G = guanine –C = cytosine These bases can be arranged differently like the letters of the alphabet to make different words. Your genetic words tell your body what protein it needs to make to get a certain job done. Remember: A pairs with T G pairs with C

Complete the dna strand… AAG GCCATAGAC

A change in the pattern creates a mutation. This may be good, bad or neutral (no effect) for the person.

Chromatin vs. Chromosomes Chromatin: unwound DNA (cell is not dividing) Chromosome: Scrunched up DNA (cell is dividing) Both are DNA!

You have 23 pairs of homologous (same size, shape and genetic info) chromosomes (23 from your mom and 23 from your dad). That’s 46 total! Each pair of chromosomes has genes for certain traits on it.

The sex chromosomes are x and y xx for a girl and xy for a boy. This means dad determines the baby’s gender! A karyotype lets you see all of the chromosomes a person has!

Cell Cycle Interphase = normal cell activity G1,S,G2 Mitosis = cell division PMAT = Prophase  Metaphase  Anaphase  Telophase Cytokinesis = cell splitting

Mitosis 1 cell divides to create 2 identical cells!

Create a mitosis flip book, write the name of the phase and draw what it looks like (we will only use the right hand side of the book for mitosis….we will use the left hand side later for meiosis)

Front Cover…. Mitosis: Cell Division 2 identical cells created

2nd page Prophase: DNA scrunches into chromosomes

3 rd page Metaphase: Chromosomes line up in the middle of the cell

4th page Anaphase: Chromatids (2 halves of the chromosome) are separated and move to opposite sides of the cell

5th page Telophase: cell begins to divide into two

6th page Cytokinesis: 2 identical cells are formed

MeiosisThe chromosome pairs separate and are divided into two different cells. This creates gametes (sperm and egg cells) that have only half as many chromosomes as the regular body cells. Body cell = 46 total chromosomes (diploid) gametes = 23 total chromosomes (haploid) Why bother splitting the number Of chromosomes in half?

Meiosis 1: –Prophase 1 = DNA scrunches into chromosomes –Metaphase 1 = chromosomes line up in the middle across from their pair –Anaphase 1 = the pairs of chromosomes separate to opposite ends –Telophase 1 = the two cells split Meiosis 2: –Metaphase 2 = chromosomes line up in the middle in a straight line –Anaphase 2 = the chromosome splits sending one copy one way and the other copy the other way –Telophase 2 = the cells separate and you know have 4 haploid gametes!

Create a meiosis flip book, write the name of the phase and draw what it looks like (use the left hand side of the flip book you created for mitosis!)

Front Cover…. Meiosis: Creates gametes (1/2 # of chromosomes)

2 nd page Meiosis 1: One body cell divides into 2

3 rd page Prophase 1: DNA scrunches into chromosomes

4 th page –Metaphase 1 = chromosomes line up in the middle across from their pair

5 th page –Anaphase 1 = the pairs of chromosomes separate to opposite ends

6 th page Telophase 1 = the two cells split

7 th page Meiosis 2: Two haploid cells divides into 4 gametes

8 th page Metaphase 2 = chromosomes line up in the middle in a straight line

9 th page Anaphase 2 = the chromosome splits sending one copy one way and the other copy the other way

10 th page –Telophase 2 = the cells separate and you know have 4 haploid gametes!