Term
| How do bacterial cells divide? |
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Definition
| By binary fission. No sexual life cycle. Reproduction is clonal. |
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Term
| What does the DNA look like in a bacterial cell? |
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Definition
| Single, circular chromosome. |
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Term
| Where does replication begin/end? |
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Definition
| Begins at origin of replication and proceeds bidirectionally to the site of termination. |
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Term
| What is the process of binary fission? |
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Definition
1.) DNA replicates
-Starts @ origin of replication
- Ends @ site of termination
2.) Both sets of DNA move to respective side
3.) Septum forms between the two sides
4.) Cell divides and genetically identical cells are created |
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Term
| In eukaryotic organisms, how many chromosomes do each specific species have? |
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Definition
|
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Term
| How many chromosomes do humans have? |
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Definition
| 46 chromosomes/ 23 nearly identical pairs. |
|
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Term
| What are chromosomes composed of? |
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Definition
| Complex DNA, RNA, and proteins. |
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Term
| The RNA is chromosomes is the site of what? |
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Definition
|
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Term
| How long is a typical strand of DNA? |
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Definition
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Term
| Is the nucleus in eukaryotes dividing or non? |
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Definition
|
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Term
| Is heterochromatin expressed or no? |
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Definition
|
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Term
| Is euchromatin expressed or no? |
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Definition
|
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Term
|
Definition
| DNA wrapped around 8 histone proteins. |
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Term
|
Definition
| Positively charged and strongly attracted to negatively charged phosphate groups of DNA. |
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Term
| How far apart are nucleosomes spaced? |
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Definition
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Term
|
Definition
| Nucleosomes that are wrapped into a higher order. 30 nanometers in width. Usual state of non dividing (interphase) chromatin. |
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Term
| What happens to the solenoid during mitosis? |
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Definition
| The solenoid is arranged around scaffold of protein to achieve maximum compaction. Radial looping. |
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Term
| What protein helps with radial looping? |
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Definition
|
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Term
|
Definition
| Array of an organism's chromosomes. Allows a geneticist to understand traits or a person. Arranged by size, staining properties, locations of centromeres etc. |
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Term
| Humans are ____ploid. ___n |
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Definition
|
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Term
|
Definition
| The number of PAIRS of chromosomes. 23 in humans. |
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Term
| A pair of chromosomes are called _________. |
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Definition
| HOMOLOGOUS PAIR. Each one in the pair is called a HOMOLOGUE. |
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Term
| What is each chromosome composed of PRIOR to replication? |
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Definition
|
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Term
| What is each chromosome composed of AFTER replication? |
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Definition
| 2 identical DNA molecules that are held together by cohesion proteins. |
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Term
| What does DNA look like after replication? |
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Definition
| 2 strands held together as a chromosome (two sister chromatids) becomes more condensed. |
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Term
| Look at pg 4 slide 12 to see difference between chromosome, sister chromatid, and homologue. |
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Definition
| Okay good looking out girl |
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Term
| What is the Eukaryotic cell cycle? (simple) |
|
Definition
1.) G1
2.) S
3.) G2
4.) Mitosis
5.) Cytokenesis |
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Term
| How long does it take to undergo the cell cycle? |
|
Definition
VARIES!
Fruit fly = 8 mins |
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Term
| Do immature or mature cells take longer to complete the cell cycle? |
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Definition
|
|
Term
| When does growth occur of the 5 stages? |
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Definition
|
|
Term
| Which phase has the most variation in time? |
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Definition
|
|
Term
| What happens in the G0 phase? |
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Definition
|
|
Term
| What is considered interphase? |
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Definition
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Term
| What happens in G1, S, and G2? simple |
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Definition
G1 - Cells undergo most of their growth.
S - Replicate DNA
G2 - Chromosomes coil more tightly using motor proteins; centrioles replicate, tubulin synthesis. |
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Term
|
Definition
| The point of constriction. |
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Term
|
Definition
| Attachment site for microtubule. |
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Term
| How to sister chromatids stay attached? |
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Definition
| At the centromere by the cohesion protein |
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|
Term
| What are the 5 phases of mitosis? |
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Definition
1.) Prophase
2.) Prometaphase
3.) Metaphase
4.) Anaphase
5.) Telophase |
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|
Term
| What are the characteristics of prophase? |
|
Definition
- Chromosomes are visible (condensed)
- Spindles begin to form
- Centrioles move to opposite poles (not in plants)
- Asters form
- Nuclear envelope breaks down. |
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Term
|
Definition
| THe point in time where you can see tightly wound DNA |
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|
Term
| What happens in pro metaphase? |
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Definition
TRANSITIONARY PHASE.
- Microtubule attachment
- The kinetochores of the sister chromatids attach to opposite poles (motor proteins in kinetochores)
- Chromosomes move toward center of cell
- Assemly/disassembly of microtubules |
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|
Term
| What happens in metaphase? |
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Definition
| Alignment of chromosomes along metaphase plate which is the future axis of cell division. |
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Term
| What happens in anaphase? |
|
Definition
-BEGINS when centromeres split with the removal of cohesion protein.
-Sister chromatids pulled to opposite poles.
- Kinetochores moved toward poles
- Poles move apart |
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|
Term
| What happens during telophase? |
|
Definition
-Spindle apparatus dissassembles
-Nuclear envelope reforms
-Chromosomes begin to uncoil
- Nucleoulus reappears in each new nucleus |
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Term
|
Definition
| Where DNA Is found. RNA synthesis. |
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|
Term
| What happens during cytogenesis? |
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Definition
| Cleavage of the cell into equal halves. |
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Term
| What happens in cytogenesis in animal cells? |
|
Definition
| Constriction of actin filaments produces a cleavage furrow. |
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|
Term
| What happens in cytogenesis in plant cells? |
|
Definition
| Vesicles aggregate to form a cell plate. |
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|
Term
| What is the cell plate in plant cells? |
|
Definition
| Fuse to form the plasma membrane |
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|
Term
| What happens in cytokinesis in fungi/protists? |
|
Definition
| Mitosis occurs within the nucleus, division of nucleus occurs within cytokinesis |
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Term
| What are the 2 controls of the cell cycle? |
|
Definition
1.) 2 irreversible points
2.) Check points |
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|
Term
| What are the 2 irreversible points? |
|
Definition
1.) Replication of genetic material.
2.) Separation of the sister chromatids |
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|
Term
| What is the purpose of the check points? |
|
Definition
| Process is checked for accuracy and can be halted if there are errors. Allows cell to respond to internal and external signals. |
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Term
| What is the G1 checkpoint? |
|
Definition
| Cell DECIDES to divide. IS EVERYTHING OK? Primary point for external signal influence. |
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|
Term
| What is the G2/M checkpoint? |
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Definition
| Cell makes commitment to mitosis. Assess success of DNA replication. IS DNA ALL GOOD? |
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|
Term
| What is the Late Metaphase checkpoint? |
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Definition
| Cell ensures all chromosomes are attached to the spindle. |
|
|
Term
| What happens if things are not correct? |
|
Definition
|
|
Term
| What is CDKS and what does it do? |
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Definition
| Cyclin-dependent kinases. Enzymes that phosphorylate proteins. |
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|
Term
| What are CDKS the primary mechanism of? |
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Definition
|
|
Term
| What was the old view on CDKS? |
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Definition
| Cyclins drove the cell cycle. They acted as a clock. |
|
|
Term
| What do we now know of CDKS? |
|
Definition
| Is controlled by phosphorylation. |
|
|
Term
| What is the cyclin complex? What is it controlled by? |
|
Definition
| CDK. Also called mitosis promoting factor. A pattern of phosphorylation. |
|
|
Term
| What happens in the G2/M checkpoint? |
|
Definition
| MPF activity is controlled by inhibitory phosphorylation of the kinase component, CDC2, and M phase cyclin is necessary for its function. CAUSED BY DAMAGE TO DNA. |
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Term
| What happens at the Spindle checkpoint? |
|
Definition
ANAPHASE PROMOTING COMPLEX
-Presence of all chromosomes at the metaphase plate and the tension on the microtubules between opposite poles are both important. |
|
|
Term
|
Definition
Anaphase.
-Securin = destructed
-Separase = accelerated to destroy cohesion |
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|
Term
| What do growth factors do? |
|
Definition
-influence the cell cycle
-trigger intracellular signaling systems
-can override cellular controls that otherwise inhibit cell division |
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Term
|
Definition
| Platelet-derived growth factor triggers cells to divide during wound healing |
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|
Term
|
Definition
| Unrestrained, uncontrolled growth of cells |
|
|
Term
| What 2 cells disrupt the cell cycle when they are mutated? |
|
Definition
1.) Tumor-suppressor genes
2.) Proto-oncogenes |
|
|
Term
| What is p53 associated with? |
|
Definition
| G1 checkpoint and tumor-suppressor genes. |
|
|
Term
|
Definition
| Monitors the integrity of DNA. If damaged, halts cell division and stimulates repair enzymes. If irreplaceable, p53 directs cell to kill itself. |
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|
Term
| P53 is ________ in many cancerous cells. |
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Definition
|
|
Term
| For a cancer to occur, ______ copies of TSG must lose function. |
|
Definition
|
|
Term
| What was the first tumor-suppressor identified? |
|
Definition
| Retinoblastoma susceptibility gene (Rb) |
|
|
Term
|
Definition
| Predisposes people for a rare form of cancer in retina of the eye. |
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|
Term
| Inheriting a single mutant copy of RB means what? |
|
Definition
| The individual has only 1 good copy left. Any error that occurs to the remaining good copy leads to a cancerous cell. A single cancerous cell leads to the formation of a retinoblastoma tumor. |
|
|
Term
| RB integrates signals from what to do what? |
|
Definition
| From growth factors to bind important regulatory proteins and prevents cyclin and CDK production |
|
|
Term
| What are proto-oncogenes? |
|
Definition
| Normal cellular genes that become oncogenes when mutated. Can cause cancer. |
|
|
Term
| What do P-OG do that encode growth factors? |
|
Definition
| Some encode receptors for growth factors. Left in "on" position that cause out of control growth without growth factors. |
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|
Term
| What else can P-OG encode? |
|
Definition
| Signal transduction proteins |
|
|
Term
| How many chromosomes needed to cause uncontrolled division? |
|
Definition
|
|
Term
| In what % of cancers is the RB mutated? |
|
Definition
|
|
Term
| In what % of cancers of p53 mutated? |
|
Definition
|
|
Term
| In what % of cancers is Ras mutated? |
|
Definition
|
|
Term
| In what % of cancers is SRC mutated? |
|
Definition
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