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34 Cards in this Set
- Front
- Back
Asexual reproduction
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generates offspring that are genetically identical to a single parent
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Sexual reproduction |
two parents contribute genetic information to produce unique offspring |
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Cell division in Prokaryotes |
binary fission, genome (chromosome) small and circular, DNA in the cytoplasm |
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Cell division in Eukaryotes |
mitosis and cytokinesis, genome (many chromosomes) large and linear, DNA in nucleus |
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Describe binary fission in prokaryotes |
single chromosome, & the origin, it starts copying the DNA, then you end up with two copies of that chromosome, they pull apart and the cells split into two |
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What is the G1 phase in the cell cycle? |
basicmetabolic energy; think about what it is doing |
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What is the S phase in the cell cycle? |
whenthe cell replicates its DNA; synthesis phase
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What is the G2 phase in the cell cycle?
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thecell is getting ready for mitosis
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What is the M phase in the cell cycle?
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mitosis |
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What is the G0 phase in the cell cycle?
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cellsthat are not actively dividing
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What is a chromosome? |
DNA;23 pairs; packed tightly into a linear structure; proteins
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What are homologous chromosomes? |
same complementary chromosome
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What are sex chromosomes? |
chromosomenumber 23, uniquely different from other chromosomes
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What is a haploid? |
onecopy of every chromosome (1n
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What is a diploid? |
twocopy of every chromosome (2n)
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What are sister chromatids? |
have homologous chromosomes and it’s the copy
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What is a centromere? |
centerof the chromosome that connects and keeps the sister chromatids together |
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What are autosomes? |
the 1-22 chromosomes
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What is prophase in Mitosis? |
DNA chromosomes condense into linear structures;nucleus starts to break down; centrosomes produce some long microtubules(spindle fibers)
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What is prometaphase in Mitosis? |
Nucleusis broken down; spindle fibers attach to the centromeres of the chromosomes
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What is metaphase in Mitosis?
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chromosomesall line up individually into the middle on the metaphase plate, spindle fibersare directing them |
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What is anaphase in Mitosis? |
spindlefibers shorten and pull apart the sister chromatids |
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What is telophase in Mitosis?
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thenucleus reforms and the chromosomes uncondensed (loose DNA)
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What happens after mitosis? |
Cytokinesis: cells split; Plants formthe cell plate and Animals pinchoff |
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What is the difference between meiosis and mitosis? |
Meiosis—4 unique daughter cells; 2n to 1n (diploid to haploid);2 cell divisions
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What is prophase I in meiosis I? |
DNA (chromosomes) condense; spindle fibers start toform, connect to centromeres, and the nucleus breaks down; homologues pair up
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What is crossing over in prophase I? |
when homologues pair up, parts of the genetic materialcrosses over from one of the sisters to the other sister chromatid
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Describe the rest of Meiosis I.
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Metaphase I—homologues line up on metaphase plate Anaphase I—pull apart· Telophase I—nucleus reforms
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Explain Meiosis II.
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Prophase II—nucleus break down, spindle fibers attach MetaphaseII—line up on plate· Anaphase—sister chromatids pull apartTelophaseII—sisters separated into four cells; 23 totalchromosomes
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Contrast meiosis in females and males. |
males start at puberty and females start before birth and resume at puberty |
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List chemicals that regulate the cellcycle.
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Cyclinand CDK form a complex; regulate the cell cycle=cyclin-CDK complexes
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List the events that these chemicalsactivate.
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G1 to S—initiate preparing DNA replication S phase—starting replication G2 to M—getting the cell ready for mitosis
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List what inactivates these chemicals (whatare the cell cycle checkpoints(?))
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1. In G1 if DNA isdamaged2. In G2 if any ofthe DNA has not been copied and will stop mitosis3. In M if thechromosomes are not lined up in the metaphase plate
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Why is cancer discussed at the end ofthis chapter?
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Constantly dividing regardless of any of these issues(ignore the stop (checkpoints)) Oncogene—cancer causing genes Proto-oncogenes—normal genes important in cell division that have thepotential to become cancerous if mutated Tumorsuppressors—encode proteins whosenormal activities inhibit cell division
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