Topic 4

Reproduction & Development

Topic 4• Vocabulary on p

60 • Gamete,

recombination, differentiation,zygote, clone

• Types of reproduction:

Asexual

Sexual

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• Examples of asexual reproduction

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• Cloning

Same end resultof asexual repro.

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• Mitosis- DNA must replicate PRIOR

• Identical• One division• Diploid diploid• Essential for growth,

development, repair, etc.

• Plant cells form cell plate= cell wall, animal cells for cleavage furrow= pinches in .

• Meiosis- DNA must replicate PRIOR

• Source of variation• Produces gametes with

haploid # (half)• Two divisions• Crossing over=variety• Non-disjunction=

failure to separate• Spermatogenesis 14• Oogenesis 11 viable

+3 polar bodies

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• Zygote Formation• Haploid gametes

unite or fuse The male gamete is mobile, the female is not.• Recombination –

refers to combining of genetic material from both sources.

• DifferentiationCells of an organism have the SAME DNA but not all the genes are expressed in all cells… early in development differentiation occurs which initiates this/gene expression.

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• Human ReproductionHormones produced in brain and reproductive organs(gonads) interact with certain tissues b/c of receptor molecules found on the cell membranes of those tissues.Hormones regulate reproductive cycles.

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• Female reproductive system:

Ovaries (gonads)Fallopian tubes or OviductUterusPlacenta- temporary organ of the fetusUmbilical cordVagina/birth canal

• Gestation= time of pregnancy from conception/fertilization till birth: development(mitosis) crucial that proper pre-natal care be taken during first few months especially b/c of organ development

• Zygoteembryofetusbaby• Labor & delivery= positive

feedback

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• Male reproductive system

Testes (gonads)ScrotumPenis

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• Applications of technology in reproduction:

IV fertilizationHormone therapyVasectomyTubal ligationPre-natal screening: amniocentesis, karyotyping, etc