DNA Cellular Reproduction Genetics FCAT Review DNA Cellular Reproduction Genetics Assembled by: Jami Shaw and Amanda Braget

DNA Deoxyribonucleic Acid (DNA)- genetic material of all organisms is made up of two twisted strands of sugar-phosphate molecules and nitrogen bases. Found in the nucleus of a cell Looks like a spiral stair case (double helix) with matching bases A-T Adenine - Thymine G-C Guanine - Cytosine

DNA Hierarchy of DNA Nitrogen bases Sugar phosphate backbone DNA= Gene (small section) Chromosome (different shape)

DNA and Genetics DNA is responsible for all of our traits It is passed from the parent to the offspring Cells must divide in order for reproduction of organisms to occur Two ways DNA is passed from parent to offspring Asexual reproduction (one parent cell) Sexual reproduction (two parent cells)

Asexual vs. Sexual Reproduction Asexual Reproduction One parent cell that has all of the chromosomes makes an identical copy of itself Parent cell then splits into two genetically identical cells These cells go through Mitosis Sexual Reproduction Two parent cells that have half the number of chromosomes must join Two cells combine giving the offspring half of the mother’s genetics and half of the father’s genetic information

Asexual VS Sexual Reproduction

Asexual vs. Sexual Reproduction

Mitosis Cell division for body cells Outcome- 2 IDENTICAL cells They have the same amount of chromosome as the parent cell Humans have 46 chromosomes

Meiosis Cell division to produce sex cells with ½ the DNA For sexual reproduction meiosis must happen in order to create cells which have HALF the number of chromosomes as the parent cell Human sex cells have 23 chromosome so together they can make 46 total chromosomes (full DNA)

Heredity – passing of traits from parents to offspring With sexual reproduction you can have different traits show up in the offspring because of different alleles in the parents Alleles – different forms a gene has for a trait A – dominant allele for a trait (upper case) a – recessive allele for a trait (lower case) Heterozygous – different alleles (Aa) Homozygous – identical alleles (AA or aa)

Punnett Squares Tools for predicting genetic crosses Genotype – genetic makeup What alleles are present Letters (A, a, B, b etc.) Phenotype – physical makeup What is shown The physical appearance (tall, short, white, red etc.)

Fill in the Punnett Square T – tall plants t – short plants What is the likelihood the plants offspring will be tall? What is the likelihood the plants offspring will be short? What percentage of offspring will be tall plants?

Fill in the Punnett Square T – tall plants t – short plants What is the likelihood the plants offspring will be tall? What is the likelihood the plants offspring will be short? What percentage of offspring will be tall plants? 2 :4 or 1:2 2:4 or 1:2 50%

Punnett Squares YOU MUST know how to compete a punnett square and tell what percentage of traits will show up in the offspring You’re percentages should always add up to 100% Pay attention to whether is asking about the genotype of phenotype