Reproduction Part 1 Reproduction and development are necessary

Reproduction Part 1

Reproduction and development are necessary for the continuation of any species. Every organism requires a set of coded instructions (their chromosomes) for specifying it’s traits. For offspring (children) to resemble their parents there must be a reliable way to transfer the information on the chromosomes from one generation to the next. This may be accomplished by asexual reproduction (one parent) or sexual reproduction (two parents). Hereditary information is contained in the genes, located in the chromosomes in each cell. I. Types of reproduction: Asexual v________ reproduction (without sex) 1. Only ______ parent. one fusion 2. No ______ (joining together) of cells or cell nuclei. 3. No special reproductive cells (eggs and sperm) or organs involved.

4. The two cells produced are _______ to identical each other and _______ to the parent cells. 5. Another name for asexual reproduction is _______. Cloning v In cloning a somatic cell (body cell) is used to create a genetically identical organism. The first successful cloning of a mammal occurred in 1996 at the Roslin Institute in Scotland 1. A donor cell is taken from a sheep’s udder 2. An egg cell is taken from an adult female sheep 7. The embryo develops normally into a lamb- Dolly 4. These two cells are fused using and electric shock 3. The nucleus of the egg cell is removed 6. The embryo is placed in the uterus of a foster mother 5. The fused cell begins dividing normally

Sexual v_________reproduction. 1. ________ parents are involved. Two 2. ________ (joining together) of two Fusion nuclei from specialized sex cells which are produced by two separate parents (for example the fusion of egg and sperm cells to produce an embryo) 3. Special reproductive cells (eggs and sperm) or inherit organs (ovaries and testes) are involved. variation 4. The offspring _______ characteristics of both parents, and this allows for ______ in the offspring

II. Mitotic Cell Division- This process is used for two purposes: 1. Reproduction in one-celled organisms. growth 2. Repair and ______ of body (somatic) cells in multicellular organisms. v Mitotic Cell Division involves two steps: 1. _______ - complex changes in the Mitosis ______ involving ______ nucleus replication of the chromosomes and separation of these identical chromosomes into two _______ sets (nuclei)

Cytoplasmic division 2. ____________ the separation of ______ cytoplasm which occurs during or at the end two of mitosis, resulting in the formation of _____ cells ______ each daughter _______ identical containing a nucleus with an _______ set of _______. chromosomes

Interphase. Chromosomes are replicating Parent Cell Chromatin condenses into chromosomes. Nuclear envelope disappears Chromosomes align at the equatorial plate Sister chromosome separate. Centomeres divide Chromatin expands. Cytoplasm divides Two daughter cells

v Mitosis is divided into stages or ______. phases 1. ______Interphase ______ Duplication of chromosomes, chromatids are attached at the _______ centomere in the center of the doubled chromosome. DNA is packed with proteins to form chromatin Two chromatids Chromosome Centomere 2. ______ Prophase - Centrioles (animal cells) separate, ______ form, nucleolus spindles disappears, __________ begins nuclearthemembrane to disappear, chromatids shorten and thicken.

Metaphase chromosomes _____ line up 3. ______(meet) on the equatorial plane, centromere replicates. 4. _____Anaphase daughter chromosomes move to poles opposite ______ (away). Telophase uncoil 5. ______chromosomes ______ disappear back to chromatin, spindle fibers ______, nuclear membrane forms, cytoplasm divides (cytokinesis) (in plants cells, cell plate forms). AS A RESULT OF MITOTIC CELL DIVISION, TWO IDENTICAL DAUGHTER CELLS ARE PRODUCED. THEY ARE IDENTICAL TO EACH OTHER AND TO THE PARENT CELL!

46 46 46 This diagram shows a human cell that has undergone Mitosis. Notice that two cells are produced. Each has 46 chromosomes and are identical to the parent cell. v Plant Cell Mitosis: 1. Mitosis in Plants occurs in developing seeds and in growing regions of roots and stems. 2. Differences in plant and animal cell mitosis: centrioles a) No ______, but spindle fibers do form. b) In telophase there is no pinching of the cytoplasm. Instead a ___________ forms which Cell plate becomes the cell wall.

Plant cell Mitosis

Comparisons between Plant and Animal Cell Mitosis Plant Cells centrioles No _______ Cytoplasm divides by Cellforming plates a __________ Animal Cells centrioles Have _______ Cytoplasm divides by Pinching in of cell _______ membrane (cytokinesis)

Cancer cell growth v ______ Cancer - Uncontrolled, abnormal , rapid mitotic cell division. This abnormal cell division invades surrounding tissues and interferes with normal tissue and organ function

v. Types of asexual reproduction (involves only mitosis) Binary Fission A. ____________ 1. The simplest form of asexual reproduction two 2. The parent organism divides into ______ equal parts. daughter cells 3. Results in two ____________ that become a separate individual and grow to normal single size. celled 4. This is the usual method of reproduction in _________ organisms. Binary Fission

Budding B. _______ 1. In unicellular organisms such as yeast, budding is similar to fission except that the cytoplasmic _______ division is ______. unequal 2. New individuals develop as small outgrowths or buds ______ on the outer surface of the parent. 3. These buds may break off and live independently or remain together to form acolony ______. Budding in yeast

4. Budding in the hydra produces a multicellular outgrowth (a new hydra) from the parent organism. This little hydra then breaks away from the parent but is genetically identical.

C. ______ Sporulation or spore formation. 1. ______ are small, microscopic, Spores nucleus specialized cells which contain a ______ and a small amount of cytoplasm surrounded by a thick outer wall. spores Moldy bread

Spore 2. These are released from ____________. cases 3. Spores can resist unfavorable environmental conditions (extreme heat and cold). When the conditions are favorable the spore can produce a new organism. 4. Bacteria, yeasts, molds mushrooms, mosses and ferns produce spores. Regeneration D. _______ whole new 1. The development of a _____ organism from a _____ of the original part organism. 2. Regeneration also refers to the replacement of lost _____ structures for example: Lobsters may regenerate a lost claw.

3. Organisms that can regenerate have many cells that are ________ meaning they have not undifferentiated yet been assigned a “job”. This lobster has regenerated a new claw. This lizard will regenerate a new tail lost perhaps in a fight Whole starfish regenerating from a lost leg Vegetative propogation D. _______________When an runner entire new plant can grow from a _____ or a ______. bud Examples: Potatoes and strawberries

Vegetative Propagation in Strawberries Mother plant Daughter plant genetically identical to mother. Vegetative propagation in potato plant The roots will develop into another potato plant genetically identical to the original.