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What are the five categories of eukaryotic microbes?
- 1) Unicellular and multicellular protozoa
- 2) Fungi
- 3) Algae
- 4) Water Molds
- 5) Slime Molds
Eukaryotic reproduction involves two types of divisions. What are they?
- 1) Nuclear division
- 2) Cytoplasmic division
Compare haploid vs diploid.
- A haploid is a nucleus with a single copy of each chromosome, and is also called a 1n nucleus.
- A diploid is a nucleus with two sets of chromosomes, and is also called a 2n nucleus.
What are the two types of nuclear division?
What happens during interphase?
During interphase, the cell grows and replicates its DNA.
What is mitosis?
Mitosis is the nuclear division of a eukaryotic cell resulting in two nuclei with the same ploidy (# of sets of chromosomes) as the original.
List and briefly explain the four phases of mitosis.
- 1) Prophase
- Cell condenses DNA molecules into visible threads called chromatids. Two identical sister chromatids are then joined together at a region called the centromere and form one chromosome. At the same time, a set of microtubules is constructed in the cytosol to form a spindle. This process typically takes place in the cytosol (the nuclear envelope will first disintegrate). However, some microbes maintain their nuclear envelopes and mitosis will occur in their nuclei.
- 2) Metaphase
- The chromosomes line up on a plane in the middle of the cell and attach their centromeres to microtubules of the spindle.
- 3) AnaphaseSister chromatids separate and crawl along the microtubules toward opposite poles of the spindle. Each chromatid is now called a chromosome.
- 4) TelophaseThe cell restores its chromosomes to their less compact, nonmitotic state, and nuclear envelopes form around the daughter nuclei.
What is meiosis?
- Meiosis is the nuclear division of diploid eukaryotic cells resulting in four haploid nuclei.
- *This is used to produce sexual reproduction cells called gametes.
What is cytokinesis?
Cytokinesis is the division of a cell's cytoplasm.
What are coenocytes?
Coenocytes are multinucleate cells resulting from repeated mitosis but postponed or absent cytokinesis.
What is schizogony?
- It is a type of reproduction performed only by certain protozoa. Multiple mitoses form a multinucleate schizont. Only then does cytokinesis occur, simultaneously releasing numerous uninucleate daughter cells called merozoites.
- *A body infected with this responds to the sudden release of the huge numbers of merozoites with the cyclic fever and chills characteristic of malaria.
What are the three characteristics that define protozoa?
- 1) Eukaryotic
- 2) Unicellular
- 3) Lack a cell wall