MENDEL’S WORK WEEK 5 NOTES CH. 3, SECTION 1 PAGE 76 - 81

I. MENDEL’S WORK a. __HEREDITY__ is the __PASSING__ of physical caharacteristics from __PARENTS__ to __OFFSPRING__ b. __DIFFERENT__ form of a __CHARACTERICSTIC__, such as stem height or seed color, is called a __TRAIT__. c. __GENETICS__ is the scientific study of __HEREDITY__ d. __HEREDITY__ is the __PASSING__ of physical caharacteristics from __PARENTS__ to __OFFSPRING__

1. MENDEL’S EXPERIMENTS a. __Mendel__ worked with __PEA PLANTS__ b. A __NEW__ organism begins to form when __EGG__ and __SPERM__ join in a process called __FERTILIZATION__ c. __POLLEN__ reaching the __PISTIL__ is called __POLLINATION__ Brain Pop: Heredity (2:28)

A. Crossing Pea Plants a. A __PUREBRED__ organism is the offspring of many __GENERATIONS__ that have the same __TRAIT__ b. Purebred __TALL__ plants will __ONLY__ have __TALL__ offspring

B. The F1 Offspring C. The F2 Offspring a. __PARENT__ plants are known as the __PARENTAL GENERATION__, or __P__ generation b. The offspring from this cross are the first __FILIAL__ generation, or the __F1__ generation c. __FILIAL__ comes for the latin work for __DAUGHTERS__ or son a. __F2__ offspring are a __MIX__ of the __P__ and __F1__ generation

D. Experiments with Other Traits a. Only 1 form of the __TRAIT__ appeared in the __F1__ generation. b. In the __F2__ generations the __LOST__ form of the __TRAIT__ always reappeared.

2. DOMINANT AND RECESSIVE ALLELES a. Individual factors, or __SETS__ of genetic information __CONTROL__ the inheritance of __TRAITS__ b. The __FACTORS__ that control each __TRAIT__ exist in __PAIRS__ c. __ONE__ factor comes from __FEMALE__ parent and the __OTHER__ factor comes from the __MALE__ parent d. One __FACTOR__ in a pair can __MASK__, or __HIDE__, the __OTHER__ factor

A. Genes and Alleles a. __GENE__ is the work for the __FACTORS__ that __CONTROL__ a trait. b. __ALLELES__ are the __DIFFERENT__ forms of genes c. __2__ alleles from the __PARENTS__ - __ONE__ from the __EGG__ and the other from the __SPERM__

Genes and Alleles Cont. d. An __ORGANISM”S__ traits are __CONTROLLED__ by the __ALLELES__ in inherits from its __PARENTS__. Some alleles are __DOMINANT__, while other __ALLELES__ are __RECESSIVE__. e. A __DOMINANT__ allele is one whose __TRAIT__ always shows up in the organism when the allele is __PRESENT__. f. A __RECESSIVE__ allele is __HIDDEN__ whenever the __DOMINANT__ allele is present. g. A __RECESSIVE__ allele will __ONLY__ show up if the organism does __NOT__ have the dominant allele BrainPop Genetics (3:04)

B. Alleles in Mendel’s Crosses a. A __HYBRID__ organism has __2__ different __ALLELES__ for a trait

C. Symbols for Alleles a. __GENETICISTS__ use __LETTERS__ to represent __ALLELES__ b. A __DOMINANT__ allele is represented with a __CAPITAL__ letter c. A __RECESSIVE__ allele is represented with a __LOWERCASE__ letter

D. Significance of Mendel’s Contribution a. __BEFORE__ Mendel the idea was a __BLEND__ of each parent, so __TALL__ + __SHORT__ = __MEDIUM__ b. Instead, __TRAITS__ are determined by __INDIVIDUAL__ separate __ALLELES__ inherited from each __PARENT__ c. Mendel is often called the __FATHER__ of __GENETICS__ 100 Greatest Discoveries: http://science.discovery.com/tv-shows/greatest-discoveries/videos/100-greatest-discoveries-shorts-genetics.htm (2:15)