Study Guide Exam I (Ch 1-5) Ch. 1 a. Model organisms (importance)
-A model organism is an organism eligible for use in studying a specific trait, disease, or processes. -Important because they allow us to understand, and gain insight on the relationship between genes and human health/disease. b. Early theories of hereditary transmission: “Genetics grew out of a historical need” i. Pangenesis, acquired, preformation, epigenesis, blending
Pangenesis: *Proposed by Darwin*
-“Gene”: Where the word genetics comes from -Specific particles in the body carry information to the reproductive organs which is then passed to the embryo during conception. Acquired: *Proposed by the Greeks*
-“Acquired”: essentially learned information/characteristics - Traits collected throughout life, combined with hereditary information and was then passed on. Preformation: *Proposed by De Beer* -The idea that inside the egg or sperm, there is a fully developed human that is just very small and needs to grow. Epigenesis: *Proposed by Caspar Freidrich Wolff* -The idea that your behaviors/environments can cause changes that affect the way that your genes work. -The process in which environmental influences alter genetic expression either negatively or positively. Blending: * Proposed by Mendel* -The idea that the inheritance of traits from two parents produces an offspring with characteristics that are a blend between those of the parents c. Important people & their contributions i. Schwann and Schleiden Theodore Schwann: (1810-1882)
-German physiologist who founded modern histology by defining the cell as the basic unit
of animal structure.
-Co-founder (with Schleiden) of the cell theory -Schwann cells named after him Matthias Schleiden: (1804-1881)
-German botanist and co-founder of cell theory (with Schwann) Cell theory: It says that all the plants and animals are composed of cells and the cell is the basic unit of life. -Cells arise from preexisting cells ii. Darwin Charles Darwin: (1809-1882)
- One of the greatest British scientists who ever lived
-Darwin proposed that species can change over time, that new species come from preexisting species, and that all species share a common ancestor iii. Mendel
Gregor Mendel: (1822-1884)
-Known as the “Father of Genetics”
-Discovered the fundamental laws of inheritance and basic principles of heredity (1866)
- He proposed that genes come in pairs and are inherited as distinct units, one from each parent
-He tracked the segregation of parental genes and their appearance in the offspring as dominant or recessive traits.
-He crossed pea plants and studies patterns of transmission iv. Flemming
Walther Flemming: (1843-1905)
-A German anatomist and a founder of the science of cytogenetics (the study of the cell's hereditary material, the chromosomes).
-He was the first to observe and describe the behavior of chromosomes in the cell nucleus during normal cell division (mitosis).
-He explained that the nucleus of reproductive cells splits twice, producing four genetically different daughter cells, each containing only one set of chromosomes v. Weismann August Weismann: (1834-1914)
- A German biologist and one of the founders of the science of genetics - Best known for the theory of the “germ plasm” which proposed a segregation between germinal and somatic cells during development, ruling out the possibility that acquired characters could be inherited. “Everything is already there”
-A model organism is an organism eligible for use in studying a specific trait, disease, or processes. -Important because they allow us to understand, and gain insight on the relationship between genes and human health/disease. b. Early theories of hereditary transmission: “Genetics grew out of a historical need” i. Pangenesis, acquired, preformation, epigenesis, blending
Pangenesis: *Proposed by Darwin*
-“Gene”: Where the word genetics comes from -Specific particles in the body carry information to the reproductive organs which is then passed to the embryo during conception. Acquired: *Proposed by the Greeks*
-“Acquired”: essentially learned information/characteristics - Traits collected throughout life, combined with hereditary information and was then passed on. Preformation: *Proposed by De Beer* -The idea that inside the egg or sperm, there is a fully developed human that is just very small and needs to grow. Epigenesis: *Proposed by Caspar Freidrich Wolff* -The idea that your behaviors/environments can cause changes that affect the way that your genes work. -The process in which environmental influences alter genetic expression either negatively or positively. Blending: * Proposed by Mendel* -The idea that the inheritance of traits from two parents produces an offspring with characteristics that are a blend between those of the parents c. Important people & their contributions i. Schwann and Schleiden Theodore Schwann: (1810-1882)
-German physiologist who founded modern histology by defining the cell as the basic unit
of animal structure.
-Co-founder (with Schleiden) of the cell theory -Schwann cells named after him Matthias Schleiden: (1804-1881)
-German botanist and co-founder of cell theory (with Schwann) Cell theory: It says that all the plants and animals are composed of cells and the cell is the basic unit of life. -Cells arise from preexisting cells ii. Darwin Charles Darwin: (1809-1882)
- One of the greatest British scientists who ever lived
-Darwin proposed that species can change over time, that new species come from preexisting species, and that all species share a common ancestor iii. Mendel
Gregor Mendel: (1822-1884)
-Known as the “Father of Genetics”
-Discovered the fundamental laws of inheritance and basic principles of heredity (1866)
- He proposed that genes come in pairs and are inherited as distinct units, one from each parent
-He tracked the segregation of parental genes and their appearance in the offspring as dominant or recessive traits.
-He crossed pea plants and studies patterns of transmission iv. Flemming
Walther Flemming: (1843-1905)
-A German anatomist and a founder of the science of cytogenetics (the study of the cell's hereditary material, the chromosomes).
-He was the first to observe and describe the behavior of chromosomes in the cell nucleus during normal cell division (mitosis).
-He explained that the nucleus of reproductive cells splits twice, producing four genetically different daughter cells, each containing only one set of chromosomes v. Weismann August Weismann: (1834-1914)
- A German biologist and one of the founders of the science of genetics - Best known for the theory of the “germ plasm” which proposed a segregation between germinal and somatic cells during development, ruling out the possibility that acquired characters could be inherited. “Everything is already there”
