180 likes | 272 Views
6.9 & 7.3. Cloning Reproduction in Flowering Plants. Cloning. Cloning is the process of forming identical genetic offspring from a single cell.
E N D
6.9 & 7.3 Cloning Reproduction in Flowering Plants
Cloning Cloning is the process of forming identical genetic offspring from a single cell. It is a natural process that happens daily in nature when organisms produce exact duplicates of themselves by asexual reproduction (binary fission, budding…). Cloning is referred to as asexual reproduction because the DNA originates from a single parent.
The First Clone Cloning started in 1958 when Frederic Stewart grew a carrot from root cells. Clones are not actually identical in appearance; rather they are identical in genetics. Remember: A clone has the genes of only 1 parent so it is genetically identical to that parent. (We have ½ our genes from one parent and ½ from the other.
Dolly In 1996, Dolly the sheep, a species much more complex than simple plants or bacteria, was cloned. She was the first fertile clone! This is the most famous cloning case to date. • Genetic information from a FINN DORSET sheep. • Enucleated ovum from a POLL DORSET sheep. • Surrogate mother Blackface sheep. • Offspring Clone of the FINN DORSET. Dolly showed signs of premature aging, possibly due to using specialized somatic cell nucleus.
Genetic information from a FINN DORSET sheep. Enucleated ovum from a POLL DORSET sheep. Surrogate mother Blackface sheep. Offspring Clone of the FINN DORSET.
ACT – Advanced Cell Technology ACT is a cell cloning company. It claims to have taken the first step in cloning a human embryo – an unborn baby in the first 8 weeks of development. The ACT clone didn’t grow beyond the tip of a ballpoint pen, only 6 cells What does the future hold?
Other Clones Dolly the Sheep (1996) Tetra the Rhesus monkey (2000) Xena the Pig (2000) Alpha and Beta Male Cattle (2001) CC the Cat (2001) Idaho Gem & Utah Pioneer the Mules (03) Dewey the Deer (2003) Prometea the Horse (2003)
Types of Cloning • Recombinant DNA Cloning: Cloning a gene of particular interest. • Reproductive Cloning: Cloning that develops into a birth. (Stem cell) • Therapeutic cloning: Cloning with the goal of studying human development to treat disease. Is cloning a human being, part or whole, ethical or unethical?
Reproduction in Flowering Plants Plants use sexual reproduction – two plants combine to make one zygote through the process of fertilization of a female sex cell by a male sex cell. Some plants have separate sexes with one type of sex organ on each (poplar trees), while some plants have both sexes on one plant – hermaphrodites (tomatoes). Most plants develop or mature in one growing season.
Plant Sex Organs Plant sex organs are very different than humans. Male Sex Organs: • Pollen – male sex cells • Stamen - anther, where pollen is produced. - Filament, holds anther away from plant. Female Sex Organs: • Eggs – female sex cells • Pistil – Sticky surface for the pollen to land on. Style – traveling chamber from stigma and ovary. Ovary – holds the egg. Plant sex organs vary in length, size, colour, and shape from plant to plant.
Ch. 6 Review Questions • P. 198-199 # 4, 5, 12, 23 & 25
Anatomy of a Flowering Plant 7.3a Stigma Anther Pollen Filament Style Petal Ovary Eggs Sepal Stem
Pollination • The process by which pollen moves from an anther to the stigma so pollen can fertilize the egg. • Can occur between plants or in the same plant. • Wind, gravity, insects, animals, and water can carry pollen. It is beneficial for pollen to be spread over large areas for greater genetic disbursement.
Fertilization • The combining of pollen and eggs to produce a zygote. • In plants , the zygote is better known as seeds. • In some plants the ovary enlarges into fruit, therefore we are actually eating ovaries. • Fruit is used for protection and disbursement ex. A bear eats berries and leaves seeds through its droppings.
Ch. 7 Review Questions • P.228-229 # 3, 4, 5, 6, 7, 10, 12 & 13