Term
| What happens in binary fission? What type of cells divide this way? |
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Definition
a. Bacteria divide by asexual binary fission
i.Single, circular bacterial chromosome is replicated, cell pinches in two |
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Term
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Definition
i. Composed of chromatin
1.DNA and protein |
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Term
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Definition
i. A complex of nucleic acids (e.g. DNA or RNA) and proteins (histones)
ii. Condenses to form a chromosome during cell division |
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Term
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Definition
i. Complex of DNA and histone proteins
ii. Promote and guide coiling of DNA |
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Term
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Definition
| a. Array of chromosomes in an individual organism |
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Term
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Definition
i. 2 complete sets of chromosomes
ii. 46 total chromosomes in humans |
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Term
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Definition
i. 1 set of chromosomes
ii. 23 in humans |
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Term
| Describe homologous chromosomes. |
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Definition
| a. One from mother, one from father |
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Term
| What happens to each chromosome prior to replication? |
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Definition
| a. Prior to replication, each chromosome composed of a single DNA molecule |
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Term
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Definition
| i. One chromosome composed of 2 sister chromatids |
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Term
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Definition
| i. Join sister chromatids |
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Term
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Definition
i. A protein complex that regulates the separation of sister chromatids during cell division
1. Either mitosis or meiosis |
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Term
| What are the 3 subphases of interphase? What happens in each? |
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Definition
a. G1
i.Growth
b. S
i. Replicate DNA
c.G2
i.Ready for mitosis |
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Term
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Definition
| i. Attachment site for microtubules |
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Term
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Definition
| i. The mitotic spindle is the macromolecular machine that segregates chromosomes to two daughter cells during mitosis |
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Term
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Definition
i. Organelle that is the main place where cell microtubules get organized
ii. They occur only in plant and animal cells |
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Term
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Definition
| i. Radial array of microtubules in animals (not plants) |
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Term
| What happens in prophase? Which organisms have centrioles? |
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Definition
a. Chromosomes condense and become visible
b. 2 centrioles move to opposite poles forming spindle apparatus (no centrioles in plants)
c. Nuclear envelope breaks down |
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Term
| What happens during prometaphase? |
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Definition
a. Sister chromatids attach to microtubules at kinetochores
b. Oriented to opposite poles
c. Move to equator |
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Term
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Definition
| a. Alignment of chromosomes along metaphase plate |
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Term
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Definition
| a. Alignment of chromosomes along metaphase plate |
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Term
| What happens in anaphase? |
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Definition
a. Centromeres split
b. Cohesin proteins removed
c. Sister chromatids pulled to opposite poles |
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Term
| What is the end result of telophase? |
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Definition
a. Spindle apparatus disassembles
b. Nuclear envelope reforms around each set of chromosomes
c. Chromosomes decondense
d. Nucleolus reappears |
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Term
| Compare animal and plant cytokinesis. |
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Definition
i. Animal cells
1. Actin filaments produces a cleavage furrow
ii. Plant cells
1. Cell plate forms between the nuclei |
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Term
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Definition
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Term
| What regulates the eukaryotic cell cycle? |
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Definition
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Term
| What is the relationship between checkpoints and the cell cycle control system? |
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Definition
a. Cell cycle can be put on hold at specific points called checkpoints
i. Process is checked for accuracy and can be halted if there are errors
ii. Allows cell to respond to internal and external signals |
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Term
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Definition
a. Act by triggering intracellular signaling systems
b. Can override cellular controls that otherwise inhibit cell division |
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Term
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Definition
i. Unrestrained, uncontrolled growth of cells
1. Failure of cell cycle control |
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Term
| Describe the significance of meiosis and the sexual life cycle. |
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Definition
a. Sexual reproduction is able to generate genetic variation in offspring because the process of meiosis randomly shuffles genes across chromosomes and then randomly separates half of those chromosomes into each gamete
b. The two gametes then randomly fuse to form a new organism
c. Genetic variation is one of the keys to evolutionary fitness |
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Term
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Definition
| i. Cell division to produce haploid sperm and egg |
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Term
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Definition
| i. Union of haploid sperm and haploid egg to form diploid zygote |
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Term
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Definition
i. During early prophase I
ii. Homologous chromosomes become closely associated
iii. Includes formation of synaptonemal complexes (tetrads) |
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Term
| What is the end result of Meiosis I? |
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Definition
| a. Results in daughter cells that contain one homologue from each chromosome pair |
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Term
| What is the end result of Meiosis II? |
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Definition
| a. Four new haploid gametes |
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Term
| Is there an interphase prior to meiosis? |
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Definition
| a. Meiotic cells have an interphase period that is similar to mitosis with G1, S, and G2 phases |
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