Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Bio Ch 15
| Question | Answer |
|---|---|
| “Omnis cellula e cellula” | Every cell originates from another cell |
| All organisms produced by a series of repeated rounds of? | cell growth and division |
| In eukaryotes, cell division via? | mitosis and meiosis |
| field of genetics involving microscopic examination of chromosomes and cell division | Cytogenetics |
| When cells get ready to divide, the chromosomes become? | compact |
| reveals number, size, and form of chromosomes in an actively dividing cell | Karyotype |
| Humans have how many pairs of chromosomes? | 23 |
| 22 pairs in humans | Autosomes |
| 1 pair in humans – XX or XY | Sex chromosomes |
| humans have 23 pairs of chromosomes | Diploid or 2n |
| gametes have 1 member of each pair of chromosomes or 23 total chromosomes | Haploid or n |
| In diploid species, members of a pair of chromosomes are called? | homologues |
| each homologue nearly identical in size and genetic composition | Autosomes |
| Both carry gene for eye color but one may have brown and the other blue | example of autosome |
| X and Y very different from each other in size and composition | Sex chromosomes |
| first gap | G1 |
| synthesis of DNA | S |
| second gap | G2 |
| mitosis and cytokinesis | M |
| G1, S, and G2 are? | Interphase |
| substitutes for G1 for cells postponing division or never dividing again | G0 |
| Cell growth occurs during what phase? | G1 |
| Chromosomes replicate in what phase? | S |
| After replication, two copies stay joined to each other and are called? | sister chromatids |
| Human cell in G1 has how many chromosomes? | 46 |
| needed during mitosis and cytokinesis | Cell synthesizes proteins |
| Division of one cell nucleus into two, with separation of sister chromatids | Mitosis |
| follows mitosis to divide the cytoplasm into two daughter cells | Cytokinesis |
| External factors in the decision to divide? | Environmental conditions; Signaling molecules |
| Internal factors in the decision to divide? | Cell cycle control molecules; Checkpoints |
| responsible for advancing a cell through the phases of the cell cycle | Cyclins or cyclin-dependent kinases (cdks) |
| are kinases controlling cell cycle | Cdks (Must bind to a cyclin to be active) |
| Three checkpoints in eukaryotes? | -G1 checkpoint (restriction point) -G2 checkpoint -Metaphase checkpoint |
| Checkpoint proteins act as what to determine if the cell is in proper condition to divide? | sensors |
| Loss of checkpoints can lead to? | mutations and cancer |
| in Mitotic Cell Division, cell divides to produce? | two new cells genetically identical to the original |
| Original cell is mother cell, new are? | daughter cells |
| Mitotic Cell Division involves? | mitosis plus cytokinesis |
| Used for asexual reproduction or for development and growth of multicellular organism | Mitotic Cell Division |
| two identical copies with associated proteins | Sister chromatids |
| When preparing for cell division, chromatids tightly associated at? | centromere |
| Ensures that each daughter cell will obtain the correct number and types of chromosomes | Mitotic spindle |
| responsible for organizing and sorting the chromosomes during mitosis | Mitotic spindle apparatus (or mitotic spindle) |
| mitotic spindle composed of? | microtubules |
| Microtubule organizing center (MTOCs) | Centrosomes |
| Animal cells have centrioles, other eukaryotes don’t (True of False) | True |
| Centrosomes duplicates at the beginning of what phase? | M |
| Spindle formed from? | microtubules |
| Microtubules formed from? | tubulin proteins |
| Three types of microtubules? | Astral, Polar, Kinetochore |
| position spindle in cell | Astral microtubules |
| separate two poles | Polar microtubules |
| attached to kinetochore bound to centromeres | Kinetochore microtubules |
| phase of the cell cycle during which the chromosomes are decondensed and found in the nucleus (G1, S, G2) | Interphase |
| Phases of mitosis (in order) | -Prophase -Prometaphase -Metaphase -Anaphase -Telophase |
| division into two daughter cells | Cytokinesis |
| -Chromosomes have already replicated and are joined as pairs of sister chromatids -Nuclear membrane dissociates into small vesicles -Chromatids condense into highly compacted structures that are readily visible by light microscopy | Prophase |
| Nuclear envelope completely fragments Mitotic spindle is fully formed Centrosomes move apart Spindle fibers interact with sister chromatids Two kinetochores on each pair of sister chromatids are attached to kinetochore microtubules from opposite poles | Prometaphase |
| -Pairs of sister chromatids are aligned along a plane halfway between the poles -Organized into a single row -When this alignment is complete, the cell is in this phase | Metaphase |
| Pairs of sister chromatids are aligned along a plane halfway between the poles called the? | metaphase plate |
| -Connections broken between sister chromatids -Kinetochore microtubules shorten, pulling chromosomes toward the pole to which they are attached -Poles move away from each other as overlapping polar microtubules lengthen and push against each other | Anaphase |
| -Chromosomes have reached their respective poles and decondense -Nuclear membranes now re-form to produce two separate nuclei | Telophase |
| In most cases, mitosis is quickly followed by? | cytokinesis |
| Two nuclei are segregated into separate daughter cells | Cytokinesis |
| cleavage furrow constricts like a drawstring to separate the cells | Cytokinesis in Animals |
| cell plate forms a cell wall between the two daughter cells | Cytokinesis in Plants |
| Sexual reproduction requires a fertilization event in which two haploid gametes unite to create a diploid cell called a? | zygote |
| the process by which haploid cells are produced from a cell that was originally diploid | Meiosis |
| Like mitosis, meiosis begins after a cell has progressed through what phases? | G1, S, and G2 |
| Two key differences in meiosis? (vs mitosis) | 1. Homologous pairs form a bivalent or tetrad 2. Crossing over |
| Homologous pairs of sister chromatids associate with each other, lying side by side to form a? | bivalent or tetrad |
| Homologous pairs of sister chromatids associate with each other, lying side by side to form a bivalent or tetrad. This is what process? | synapsis |
| a protein structure that connects homologous chromosomes | Synaptonemal complex |
| -Physical exchange between chromosome pieces of the crossing bivalent -May increase the genetic variation of a species | Crossing over |
| arms of the chromosomes tend to separate but remain adhered at a crossover site | Chiasma |
| chromosomes condense, bivalents form and the nuclear membrane breaks down | Prophase I |
| -spindle apparatus complete, chromatids attach to kinetochore microtubules -Pairs of sister chromatids attached to single pole | Prometaphase I |
| bivalents organized along metaphase plate as double row | Metaphase I |
| segregation of homologues occurs | Anaphase I |
| sister chromatids have reached their respective poles and decondense and nuclear membranes reform | Telophase I |
| two haploid cells, with no pairs of homologous chromosomes | End of meiosis I |
| No S phase between? | meiosis I and meiosis II |
| Sister chromatids separated in? | anaphase II, unlike anaphase I |
| Sorting events of meiosis II are similar to those of? | mitosis |
| Mitosis produces? | two diploid daughter cells that are genetically identical (ex: 6 chromosomes in 3 homologous pairs) |
| Meiosis produces? | four haploid daughter cells (ex: Each daughter has random mix of 3 chromosomes) |
| Sequence of events that produces another generation of organisms | Sexual life cycle |
| involves an alternation between haploid cells or organisms and diploid cells or organisms | Sexual life cycle for sexually reproducing organisms |
| Most animal species are? | diploid |
| are a specialized type of cell | Haploid gametes |
| unite to form diploid zygote, then proceed immediately through meiosis to make four haploid spores | Haploid cells |
| Haploid-dominant species? | Many fungi and some protists Multicellular organism |
| Multicellular diploid organism | sporophyte |
| Multicellular haploid organism | gametophyte |
| Variations in chromosome structure and number can have? | major effects on organisms |
| Between species is it normal for structure and number of chromosomes to vary? | yes |
| Chromosome composition within a given species tends to remain? | relatively constant |
| 2 sets of 23 chromosomes (total of 46) | Humans |
| 2 sets of 39 chromosomes (total of 78) | Dog |
| 2 sets of 4 chromosomes (total of 8) | Fruit fly |
| 2 sets of 12 chromosomes (total of 24) | Tomato |
| Chromosome identification through? | Size, location of centromere, banding pattern |
| centromere at the end | Telocentric |
| centromere near end | Acrocentric |
| centromere off center | Submetacentric |
| centromere middle | Metacentric |
| short arm of chromosome is? | p |
| long arm of chromosome is? | q |
| Segment of chromosome missing | Deletions |
| Repeated segment of chromosome | Duplications |
| A segment has a change in direction along a single chromosome (can break genes at ends or separate from regulatory regions) | Inversions |
| One segment becomes attached to another chromosome May be simple or reciprocal | Translocations |
| the normal number of chromosomes (In a diploid organism, two sets is normal) | Euploid |
| 3 or more sets of chromosomes | Polyploid |
| Abnormal number of a particular chromosome | Aneuploidy |
| Missing one of normal copies of a chromosome | Monosomic |
| Normal 2 copies of a chromosome plus a 3rd | Trisomic |
| -Chromosomes do not sort properly during cell division -During meiosis can produce aneuploid gametes (too many or too few chromosomes) | Nondisjunction |
| In animals, deviations from diploidy are usually? | lethal |
| Plants commonly exhibit? | polyploidy |
| Trisomic and monosomic individuals have? | an imbalance in the level of expression of genes on different chromosomes that interact in the cell (disrupts cell function) |
Created by:
lnharrold