Post on 25-May-2015
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Homework from last class:Homework from last class:Complete the Onion Root Lab Activity
and The Cell Cycle and Cancer worksheet
Read notes on Cancer on the class blog (in this slideshow)
Keep working on your Mitotic Movies project
Read over class notes and check out the class blog: http://msoonscience.blogspot.com/
Ch 5.1 ReviewCh 5.1 ReviewWho can tell me…1) What are the phases of mitosis?
prophase, metaphase, anaphase, telophase
2) What do the nucleus and chromosomes look like during prophase?- Nucleolus disappears, nuclear membrane begins to break down.
- Chromosomes become visible and they attach themselves to spindle fibers at the centromeres.
3) How does cytokinesis differ in plant and animal cells?
animal cell: cell membrane pinches together and the cell divides
plant cell: cell plate forms to make new cell wall and cell membrane
Ch 5.1 ReviewCh 5.1 ReviewWho can tell me…4) What is the importance of checkpoints
in the cell cycle?- At these checkpoints, the cell can be stopped from growing or dividing if conditions are unsuitable.
- Important for survival of the organism.
5) What may happen if the checkpoint proteins no longer function?If a mutation occurs in a gene producing the instructions for the checkpoint protein, then cell cycle control will be lost could lead to cancer.
Asexual ReproductionAsexual ReproductionChapter 5.2 pp. 166-178
Asexual ReproductionAsexual ReproductionWhat is asexual reproduction?
asexual reproduction: reproduction that requires only one parent and produces offspring that are genetic copies of the parent
Asexual ReproductionAsexual ReproductionA clone is an identical genetic copy of its
parent.Many organisms naturally form clones via
asexual reproduction.Cloning is also used in agriculture and
research to copy desired organisms, tissues and genes.
Examples?Animals (sheep, pigs, cattle, horses)Plants (ornamental shrubs, trees)Livestock breeds and plant production Skin cells (grow new tissue for burn victims)Healthy genes (replace mutated ones)
Dolly the sheep – the world’s first cloned
animal
Activity time!Types of Asexual
Reproduction
Activity Instructions:Activity Instructions: I will make 6 groups – each group will research a
particular kind of asexual reproduction: (starts on p. 168)
Binary FissionBuddingFragmentationVegetative Reproduction
Benefits of Vegetative ReproductionSpore Formation
15 minutes to summarize your assigned type of asexual reproduction – use the information in the textbook.
Each group member must choose a role:
writer, encourager, discussion leader, questioner, conflict negotiator
Activity Instructions:Activity Instructions:Write your summary on the transparency
and present your information to the class.
You will complete a self-evaluation and will receive a teacher evaluation for your group effort and accuracy.
You will be quizzed on this material after
the activity so pay attention!!!
Types of Asexual
Reproduction
Binary Fission – p. 168-Binary Fission – p. 168-169169Binary fission: single parent cell organism splitting into 2 identical copies Binary fission is the only method of reproduction for some types of bacteria.
◦ Since bacteria do not have a nucleus, they do not undergo mitosis; however, the one ring of DNA does replicate◦ In favourable environmental conditions, bacteria can reproduce every 20 minutes!
Budding – p. 170Budding – p. 170Budding - areas of multicellular organisms undergo repeated mitosis and cell division to form an identical organism. Buds sometimes detach to form a separate organism.
◦ Example: Hydra, sponges, and yeast
Budding yeast cells
Fragmentation – p. 170 - Fragmentation – p. 170 - 171171Fragmentation - part of an organism breaks off due to injury, and the part grows into a clone of the parent
Examples: Sea star - if an arm detaches, it can develop into another sea star
Plants - aquatic weeds (e.g. Eurasian milfoil)
Sea Star Regeneration video: http://www.youtube.com/watch?v=f7cXeWxxfD4&feature=player_embedded
Vegetative Reproduction – Vegetative Reproduction – p. 172p. 172Vegetative reproduction - special cells in plants (usually in stems or roots) that develop into structures that form new plants identical to the parent
Examples: Tulip, daffodil, hyacinth bulbs, potatoes, strawberries
Main disadvantage: new plants grow very close together competition for resources (soil, nutrients, light)
Vegetative Reproduction – Vegetative Reproduction – p. 172p. 172Main benefits: Can allow crop harvest (e.g. potatoes), can make cuttings and grafts of house plants
In grafting, parts of a desirable plant are removed and attached to a rooted stock of another plant
p. 174
Spore Formation – p. 174Spore Formation – p. 174Spore formation - some bacteria, micro-organisms and fungi can form spores - single reproductive cells that can grow into a whole new organism by mitosis Light weight - can be carried by wind or water
Can grow in suitable environment (enough moisture, temperature, and food)
Have tough outer coating to allow them to survive harsh conditions
Examples: bread mold, mosses, ferns
Advantages and Advantages and Disadvantages:Disadvantages:Asexual ReproductionAsexual ReproductionTable 5.1 p. 175
Homework for next class:Homework for next class:Answer Reading Check Questions 1-5 p.
178Study for Quiz on Asexual
Reproduction Keep working on your Mitotic Movies
project - due March 8 for Science 9 (1-1) and March 9 for Science 9 (2-4)
Read over class notes and check out the class blog: http://msoonscience.blogspot.com/
Works CitedWorks CitedImages taken from the following sources:http://www.saburchill.com/ans02/chapters/chap051.html
http://www.tutornext.com/help/yeast-reproduction-budding
http://www.cosmosmagazine.com/news/392/hello-dolly-the-sheep-changed-world
http://regentsprep.org/regents/biology/units/reproduction/asexual.cfm
http://andyannie.pbworks.com/w/page/5454436/Reproduction
http://www.labtechindia.net/budding-in-hydra-1612.html
http://resources.schoolscience.co.uk/sgm/sgmmicrobes3.html
http://teacher2.smithtown.k12.ny.us/ksiolos/Science/Science8/Science8Units/R&D.htm
http://regentsprep.org/regents/biology/units/reproduction/asexual.cfm