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Tuesday, January 5 th, 2016 Genetics Agenda: Welcome Back!! Ø Review: Policies, Office Hours and Seating Chart Ø Activity: Genetics Vocabulary Worksheet due at the end of the hour TODAY!! Homework/Class Work: 1. Genetics Vocabulary Worksheet due Today for 26 Points 2. New Science Notebooks due Friday 1/8/2016
Necessary Materials for the Science Folders • All Biology students will be REQUIRED maintain & Folder (1 per quarter) ONLY for Biology!! • They will be graded periodically • Students may use them as a resource while studying for the exams • Materials Needed: • 1 Folder per quarter (4 total for the year) with prongs in the center • Loose leaf paper • Pens/Pencils • NEW FOLDER DUE THIS FRIDAY 1/8/2016
SEATING CHART!!! As you hear your name called, please take a seat in your new assigned seat!
Genetics: https: //www. youtube. com/watch? v=B_PQ 8 q. Yt. UL 0 Following the video clip, please take out your Genetics Vocabulary Sheet and pick up a Biology Textbook!!
Wednesday/Thursday 1/6 -1/7/2016 Genetics Agenda: Introduction to Genetics!! Ø Activity: Finish Genetics Vocab Group Definitions Ø Notes: Intro to Genetics Ø Activity: Brain Pop and Worksheet Ø Activity: Genetic Terms Review Ø Activity: Genetics Practice Problems Part I Homework/Class Work: 1. Homework: Genetics Practice Problems Part I worksheet due Friday 1/8/2016 for 10 Points
GENETIC TERMS • Gene: a sequence of DNA that encodes for a certain trait • Allele: one of two (or more) alternative forms of a gene (a single letter) • Dominant Allele: an allele that dictates the expression of a trait (capital letter, ex: A) • Recessive Allele: an allele whose trait is masked by the presence of a dominant allele (lower case letter, ex: a)
TERMS • Genotype: genetic make-up of an organism (letter combination) • Phenotype: physical appearance of an organism (its outward physical appearance) • Homozygous: both alleles in a gene pair code for the same trait (ex: AA or aa) • Heterozygous: the two alleles in a gene pair that do not code for the same trait (ex: Aa)
TERMS • Sex Chromosome: the chromosome that determines the sex of an organism (the X and Y chromosome) • Autosome: any chromosome that is not a sex chromosome • Punnett Square: a chart which shows all possible gene combinations in a cross of parents • Monohybrid cross: a cross between two individuals for one trait (ex: Aa x Aa) • Dihybrid cross: crossing two different characteristics at the same time (Aa. Bb x Aa. Bb)
1. Chimp’s & human’s DNA are 98% identical. 2. The father determines the sex of the offspring. 3. A genetic blood disorder can make your skin look blue. 4. A person may transmit characteristics to their offspring which he/she do not show themselves. 5. Geneticists have created a potato that can self destruct. 6. We share 40 -50% of our DNA with cabbages 7. Scientists estimate that 99. 9 percent of the DNA of most humans is identical. 8. Each parent contributes half of their child’s genetic make-up. 9. Henrietta Lacks was a woman with a mutation who had immortal cells, who later died of cervical cancer (kidney injury) 10. Humans share 50% of their DNA with bananas.
Genetics: THE FIELD OF BIOLOGY DEVOTED TO UNDERSTANDING HOW CHARACTERISTICS ARE PASSED FROM PARENT TO OFFSPRING.
GREGOR MENDEL (1823 – 1884) • AUSTRIAN MONK WHO STUDIED MATH & STATISTICS. • HE BECAME KNOWN AS THE “FATHER OF GENETICS”. • HE CONDUCTED EXPERIMENTS ON PEA PLANTS.
MENDEL’S PEA PLANT EXPERIEMENTS • He observed 7 characteristics of pea plants • each characteristic had only 2 contrasting traits. - height - flower position along the stem - pod appearance - pod color - seed texture - seed color - flower color
MENDEL’S EXPERIMENT 1. GREW ONLY PLANTS THAT WERE PURE FOR EACH TRAIT. -he had plants self-pollinate for several generations. 2. CROSS-POLLINATED CONTRASTING TRAITS. -ex: he crossed a yellow pod plant with a green. 3. THE 1 ST CROSS WAS LABELED AS THE PARENTAL GENERATION (P).
4. THE OFFSPRING WERE LABELED AS THE F 1 GENERATION 5. MENDEL ALLOWED THE F 1 GENERATION TO SELF-POLLINATE & THOSE OFFSPRING WERE THE F 2 GENERATION.
MENDEL’S RESULTS • AFTER CROSSING A PURE GREEN PODDED PLANT (P) WITH A PURE YELLOW (P) ALL OF THE OFFSPRING WERE GREEN. • AFTER THESE OFFSPRING (F 1) WERE CROSSED THE RESULTING OFFSPRING (F 2) CAME OUT TO A 3 TO 1 RATIO FOR GREEN PODDED PLANTS.
MENDEL’S LAWS • LAW OF SEGREGATION - two alleles for a character will separate when a gamete is formed • LAW OF INDEPENDENT ASSORTMENT: -The factors for different characteristics are not connected
QUESTION EXPLAIN WHY MENDEL GOT THE RESULTS HE DID WITH THE PARENTAL GENERATION?
ANSWER Because the green color is considered dominant & it covers or masks the yellow color trait (recessive)
QUESTION If all of the offspring were green and then they were cross pollinated, why didn’t these offspring come out all green?
ANSWER Because the offspring from F 1 generation carried a hidden yellow factor that could be passed on to the offspring of F 2 generation.
The Testcross • A genetic procedure devised by Mendel to determine an individual’s actual genetic composition • A purple-flowered plant can be homozygous dominant (PP) or heterozygous (Pp) • One cannot tell by simply looking at the phenotype • One can tell from the results of a cross between the test plant and a homozygous recessive plant
How Mendel used the testcross to detect heterozygotes.
BRAIN POP: HEREDITY https: //www. brainpop. com/science/cellularlifeandgenetics/heredity/
Hereditary Practice On the BACK of your Hereditary Brain. Pop worksheet, make 4 quadrants and answer the following scenarios using the Punnett square method. 1. C= Cleft chin, c = no cleft chin ü Heterozygous mom crossed with heterozygous dad 2. W= Widow’s peak, w = no widow’s peak ü Homozygous dominant mom crossed with homozygous recessive dad 3. S= normal blood cells, s= Sickle cell anemia disease (sickled shaped cells) ü Heterozygous mom crossed with homozygous recessive dad 4. A= normal pigment, a= albinism (light to white hair, skin and eyes) ü Homozygous recessive mom crossed with homozygous dominant dad
Friday, January 8 th, 2016 Genetics Agenda: Crossing Genes Ø Notes: Genotypic vs. Phenotypic Ratios Ø Activity: Monohybrid Cross Practice Ø Activity: Genes with Smile Homework/Class Work: Genes with a Smile due Today 1/8/2016 (Gradebook) for 30 Points
Genotypic Ratio VS Phenotypic Ratio • Genotypic Ratio: the number of times each genotype appears in the offspring. Written from most dominant trait to the recessive. ( # of AA, # of Aa, # of aa) • Phenotypic Ratio: the number of times each phenotype appears in the offspring. Written from the dominant trait to the recessive. (# of dominant, # of recessive)
Punnett Squares • A Punnett square is a chart which shows all possible gene combinations in a cross of parents. • Horizontally across the top of the chart are the possible gametes of one parent. • Vertically down the side of the chart are the possible gametes of the other parent. • In the boxes of the chart are the possible genotypes of the offspring. TT x tt t t T T Tt Tt
LET’S TRY ONE!!!! *Brown = dominant* B= brown Bb x bb eyes b= blue B The eyesgenotypic ratio is: 0: 2: 2 b B b b The phenotypic ratio is: 2: 2 B b b b
C= Straight hair Monohybrid c= curly hair Cross: GENOTYPIC RATIO: two heterozygous 1: 2: 1 individuals CC: Cc: c Cc x Cc C c c Homozygous dominant: Heterozygous: Homozygous recessive C PHENOTYPIC RATIO: 3: 1 Straight: cu rly Dominant: Recess ive c CC Cc Cc cc IN YOUR