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A+P Test 1 Ch3c
Nucleus and Cell Division
Question | Answer |
---|---|
Parts of nucleus | Nuclear envelope containing nucleus containing one or more nucleoli. |
Have no nucleus. | Red blood cells. |
Have multiple nuclei. | Skeletal muscle cells. |
nucleoli | Make ribosomes. Cluster of protein, DNA, and RNA. |
Genetic info organization. Humans? | Genes arranged along chromosomes. Human somatic (body) cells have 46 chromosomes, 23 from each parent. |
Name for total genetic info carried in a cell or an organism. When was human one mapped? | Genome. Human Genome Project completed in April 2003 (3.2 billion nucleotides. 0.1% account for inherited differences. About 30,000 human genes.) |
How are genes expressed? | TRANSCRIPTION: Info of specific region of DNA is copied to produce a specific RNA. Then, in TRANSLATION, the RNA attaches to a ribosome where the info in RNA is translated into a corresponding sequence of amino acids to form a nw protein molecule. |
In what form is genetic info stored? | Sequences of nucleotide (base) triplets represent genetic info and serve as templates. |
What are the types of RNA made from the DNA nucleotide template? | mRNA directs protein synthesis rRNA hold info for making ribosomes (joins with ribosomal proteins to do so) tRNA binds to amino acids to hold in place on a ribosome until needed for protein synthesis. |
How do bases pair in transcription? | DNA Cytocine with RNA Guanine DNA Guanine with RNA cytocine DNA adenine with RNA uracil DNA thymine with RNA adenine |
tRNA | transferRNA bind amino acids to ribosome until needed by ribosome for making a protein |
mRNA | messanger RNA directs protein synthesis |
rRNA | ribosomal RNA holds info for making ribosomes and binds with ribosomal proteins to make ribosomes (in nucleoli) |
Reproductive Cell Division | Chromosomal replication, then Meiosis- the making of gamites. 46 chromosomes become 23. 1 cell becomes 4 cells. |
Somatic Cell Division | Mitosis (nuclear division) + Cytokinesis (cytoplasmic division). Cell's 46 chromosomes copied and remain the same number in the 2 resulting cells. |
Why do somatic cells divide? | Replace old and damaged cells. |
Cytokinesis | dividing of cytoplasm |
Nerve cell cycle | Always active and nondividing. Never enter interphase. Said to be in G zero. G = gap. |
Interphase | Replication of DNA and many organelles (thus a high metabolic rate during this phase). |
Prophase | Start of mitosis. Microtubules start latching onto organelles. The nucleus and nuclear envelope breaks down. |
Metaphase | Everything in Midline. |
Anaphase | Material moves toward the poles and a cleavage furrow begins to show (=cytokinesis begins). |
Indent of cell membrane | Cleavage furrow. |
Telophase | Nucleus and nuclear envelope builds back up. Almost two cells.Cytokinesis complete after this phase. |
Somatic cell division stages | IPMAT (or I then mitosis then cytokenisis |
Reproductive cell division stages | IPMAT PMAT (or I, then meiosis 1, then meiosis 2) |
5 Aging Theories | 1.Free radicles 2. Cell genetically programmed to replicate only so many times 3. Autoimmune responses 4. Telomere destruction and resulting damage to chromosomes 5. Environmental Factors (foods, water, air radiation... cancer, cell damage....) |
Necrosis | Pathological cell death (disease, injury, lack of blood) |
apoptosis | programmed cell death (as embryo) |