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zygote
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cell that develops into offspring
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embryo
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unprotected or unhatched off spring
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genetic diversity
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inherited genetic differences in a species
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sustainability
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ability of environment to keep supporting its organisms into future
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reproduction
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ensures life exists beyond its present gen. and species exist in future
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Chromatin
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Condensed form of DNA
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Nitrogen bases
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"steps of DNA"; a with t, c with g
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Chromosomes
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condensed chromatin for reproduction
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Homolog pairs
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chromes that are the same shape, size, have same genetic info in same spot; one from ea. parent
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binary fission
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mitosis in prokaryotes
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budding
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buds in multicelluar can detach through repeated mitosis and form separate org.
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frag.
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part of multicelluar breaks off due to injury and becomes separate org.
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vegetative.
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stems, leaves, or roots are used to asex. repro.
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spore
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spores grow into new org.
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prophase
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nuclear membrane disappears, fibres attach to centromeres
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metaphase
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chromes align on equator
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anaphase
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fibers pull sister chromatids to poles
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telophase
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fibres disappear and membrane reforms around each set
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(cytokinesis)
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cell contents are divided into 2 cells
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cleavage furrow or cell plate
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morula
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end of week one
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ball of cells
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blastula
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end of week two
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hollow ball of cells, cell can develop to any kind
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gastrula
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3 distinct layers of cells (DIFFERENTIATION)
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ecto: skin/ nerves, mes: muscles/bones, end: lungs/liver/digestive system lining
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lots of offspring quickly, large colonies can form to out-compete, lots=many may survive if conditions change, less energy
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disease/mute=death, compete for food and space, bad condition=wiped out
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genetic diversity, ext: little energy to mate, more offspring can exist after disaster, int: more protect and care
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int: more energy/risk to mate, fewer produced, ext: gams,embryos, offs are unprotect
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external
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very little energy mate, lots of offspring, spread widely in evrionment (less comp.)
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many gametes die, many eggs aren't fertilized, offspring are unprotected
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internal
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embryo protected, offspring's parents will protect
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more energy, fewer zygotes, more energy to raise
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differentiation
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formation of organs/tissue from gastrula
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1st tri
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0-12 wks
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development of all organ systems
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2nd tri
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12-24
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rapid growth (12-16); fetal movements felt
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3rd tri
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24-38
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continued growth (brain)
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prophase
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spindle fibres form and push centris. to poles, homolo chromosomes are paired
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cross over
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metaphase
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homolo chromosomes align on 2 sides of equator
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anaphase
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homolo chromosome pairs separate to opposite poles
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assort
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telophase
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2 nuclei form, after 2 cells form
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mating
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egg and sperm come together at same time and place
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fertilization
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gametes fuse to make zygote
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development
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embryo develops
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Cheatography n. The art of mapping complex subjects into clear, instantly navigable reference guides.
