Homeroom Warm Up 3-4-15 List the 4 major layers of the Earth from the hottest to the coolest. Also list at least one fact about each layer.

Science Warm Up 3-4-15 Scientist theorize that the Atlantic Ocean is slowly increasing in width. Which is the best approximation of the rate at which lithospheric plates beneath the Atlantic Ocean are moving? 2 millimeters per year 2 centimeters per year 2 meters per year 2 kilometers per year

Vocabulary Words You should be able to define all of the following words Genes Genotype Phenotype Chromosome Inherited Trait Recessive Trait Dominant Trait Heredity Homozygous Heterozygous

Unit A : Chapter 1 : Section 1 GLEs GLE 0707.4.3 Explain the relationship among genes, chromosomes, and inherited traits. GLE 0707.4.4 Predict the probable appearance of offspring based on the genetic characteristics of the parents. Unit A : Chapter 1 : Section 1

What is genetics? The scientific study of heredity

Gregor Mendel (1822-1884) The Father of Genetics Mendelian Genetics 2/15/2019 Gregor Mendel (1822-1884) The Father of Genetics This has been modified from the original ppt Oct. 2011 copyright cmassengale

Gregor Johann Mendel Austrian monk Mendelian Genetics 2/15/2019 Gregor Johann Mendel Austrian monk Studied the inheritance of traits in pea plants Developed the laws of inheritance Mendel's work was not recognized until the turn of the 20th century

copyright cmassengale Mendelian Genetics 2/15/2019 Gregor Johann Mendel Between 1856 and 1863, Mendel cultivated and tested thousands of pea plants He found that the plants' offspring retained traits of the parents copyright cmassengale

Particulate Inheritance Mendelian Genetics 2/15/2019 Particulate Inheritance Mendel stated that physical traits are inherited as “particles” Mendel did not know that the “particles” were actually Chromosomes & DNA copyright cmassengale

copyright cmassengale Mendelian Genetics 2/15/2019 Why peas? Can be grown in a small area Produce lots of offspring Produce pure plants when allowed to self-pollinate several generations Can be artificially cross-pollinated copyright cmassengale

Mendel and His Peas Mendel tested 7 traits: Flower color Flower position Seed color Seed shape Pod shape Pod color Plant height http://www.fieldmuseum.org/exhibits/traveling_mendel.htm

Mendel and His Peas Mendel crossed flowers that were true-breeding for each characteristic. He crossed a purple (PP) flowered plant with a white (pp) flowered plant. (Parent Generation) http://biology.kenyon.edu/courses/biol114/KH_lecture_images/Mendel/Mendel.html

Mendel and His Peas Purple Parent (PP) The first generation (F1) of plants all had purple flowers. Where did the white color go?? White Parent (pp)   (Pp)    (Pp)    (Pp)

Mendel and His Peas Mendel took two of his first generation (F1 x F1) purple flowered plants and crossed them together. In the second generation (F2) he had 3 purple flowered plants, and 1 white flowered plant. Purple Parent (Pp) Purple Parent (Pp)    (PP)   (Pp)   (Pp)   (pp)

Mendel and His Peas Mendel noticed in the first generation, all of the white flowers seemed to disappear. He called this a recessive trait. The white color faded into the background at first. It showed up in the next generation when he pollinated the flowers.

Mendel and His Peas The color (purple) that seemed to mask over the recessive color was named the dominant trait.

Mendel and His Peas Mendel was responsible for figuring out that each plant carried two sets of instructions for each characteristic (one from the “mom” and one from the “dad”). Like many scientists, his work was not accepted until after his death.

Let’s Review 1. If you crossed a true-breeding black rabbit with a true-breeding white rabbit, all of the offspring would be black. Which trait is dominant in rabbits: black fur or white fur? 2. Which trait is recessive?

Answer Black Rabbit (BB) The trait for black fur is dominant over the trait for white fur. The white fur trait is recessive. White Rabbit (bb)   (Bb)   (Bb) http://www.buckeyevalleyfarms.freeservers.com/photo.html

Mendel and His Peas Vocabulary Heredity- the passing of traits from parent to offspring. 2. Dominant trait- the trait observed when at least one dominant allele for a characteristic is inherited 3. Recessive trait- a trait that is apparent only when two recessive alleles for the same characteristic are inherited

Mendel and His Peas 4. Genes- a segment of DNA that carries hereditary instructions and is passed from parent to offspring. Genes are located on chromosomes. 5. Alleles- multiple forms of the same gene 6. Genotype- an organisms inherited combination of alleles 7. Phenotype- an organisms inherited appearance

Probability The likelihood of a particular event occurring. Chance Can be expressed as a fraction or a percent. Example: coin flip.

Punnett Square Developed by Reginald Punnett. A diagram used to show the probability or chances of a certain trait being passed from one generation to another.

Reading Punnett squares Gametes are placed above and to the left of the square Offspring are placed in the square. Capital letters (Y) represent dominant alleles. Lower case letters (y) represent recessive alleles.

genotypes Homozygous = when an organism possesses two identical alleles. ex. YY or yy Heterozygous = when an organism possesses different alleles. ex. Yy

Phenotype vs genotype Genotype The genetic makeup Symbolized with letters Tt or TT Phenotype Physical appearance of the organism Expression of the trait Short, tall, yellow, smooth, etc.

Punnett square example

Unit A : Chapter 1 : Section 1 More Practice Unit A : Chapter 1 : Section 1

Punnett square review:

Science Closure 3-4-15 The image shows a chromosome. What is located on the chromosome? A cells B genes C enzymes D organelles

Unit A : Chapter 1 : Section 1 Science Closure 2-28-14 In a certain breed of dog, short hair (H) is dominant to long hair (h). A short-haired dog (Hh) is crossed with a long-haired dog (hh). A Punnett square of this cross is shown below. What is the probability that one of the puppies produced by these parents will have short hair? A. 0% B. 25% C. 50% D.100% Unit A : Chapter 1 : Section 1