Microtubules outside the nucleus assembled together during prophase

.

A 3D structure widest in the middle & tapering to a point at the 2 poles in prophase.

Not seen during prophase.

Imaginary midline between 2 poles in metaphase

.

Shallow groove near the location of the old metaphase plate in cytokensis.

Only in animal cells.

No cleavage furrow.

Have a cell wall unlike animal cells.

• The chromosomes condense and become visible
• The centrioles form and move toward the poles
• The nuclear membrane begins to dissolve
• The homologs pair up, forming a tetrad
• Each tetrad is comprised of four chromotids - the two homologs, each with their sister chromatid

CROSSING OVER (XO)

[image]

When homologous chromosomes swap genetic material.

Serves to increase genetic diversity by creating four unique chromatids.

Occurs in Meiosis 1- Prophase 1[image]

• Microtubules grow from the centrioles and attach to the centromeres
• The tetrads line up along the cell equator

• The centromeres break and homologous chromosomes separate (note that the sister chromatids are still attached)
• Cytokinesis begins

• The chromosomes may decondense (depends on species)
• Cytokinesis reaches completion, creating two haploid daughter cells

Meiosis is Egg and Sperm

Mitosis is Identical Twins

• Centrioles form and move toward the poles
• The nuclear membrane dissolves

• Microtubules grow from the centrioles and attach to the centromeres
• The sister chromatids line up along the cell equator

• The centromeres break and sister chromatids separate 
• Cytokinesis begins

• The chromosomes may decondense (depends on species)
• Cytokinesis reaches completion, creating four haploid daughter cells

[image]

Phosphate

Sugar- ribose (RNA) deoxyribose (DNA)

Bases- Prymidines (Cytosine [in both RNA and DNA], Thymine [only in DNA], Uracil [only in RNA]),

Purines (Adenine and Guanine [both in RNA and DNA])

A species that plays a critical role in maintaining the structure of an ecological community and whose impact on the community is greater than would be expected based on its relative abundance or total biomass.

Predators (organisms that prey on other organisms), Mutualists (organisms that benefit eachother and if one dies then the entire ecosystem is jepoardized) , and Ecosystem Engineers (organisms that provide nutrients or habitats for other organisms)

Producers are autotrophic organisms containing most plants and a few microorganisms. Use the energy of the sun or chemical energy to sythesize organic (carbon-containing) compounds from inorganic compounds.

Consumers are hetertrophic organisms that feed off other organisms.

Consume secondary consumers. Also considered carnivores

.

1) the ash from the previous plants forms a fertilizer for colonizing
plants
2) seed germination can be stimulated by fires
3) blooming can be triggered by fires
 4) non-fire adapted vegetation is
prevented from invading and blocking out the sunlight for the many species of
herbs that thrive in a properly maintained forest.