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Reproduction be very cool. Grade 2 science test cheatsheet

Asexual Reprod­uction: Cell Cycle

Interphase
Mitosis
Cytoki­nesis
Cell grows and develops & does normal functions, longest cell cycle phase, late interphase DNA replic­ation occurs
Prophase: Nucleolus disapp­ears, spindle fibres form & attach to centro­meres
Cell divides into 2 daughter cells
Dna molecule unwinds with help of enzyme, bases pair up= 2 geneti­cally id DNA molecs.
Metaphase: Spindle fibres lineup at equator of cell
For both binary and cell cycle
Mitosis: Anaphase: Spindle fibres pull sis. chromatids to opp. poles
Telophase: Nuclear membrane reappears around sis chromatids
Eukaryotic cells use cell cycle

Sexual Reprod­uction Cell Cycle

Meiosis 1
Meiosis 2
Prophase 1: Nucleolus dissolves, Nucleolus dissolves, spindle fibres form, homologous chromo­somes pair, spindle fibres attach to centro­meres, DNA condenses to chromo­somes. Pro 2= same no homo
Metaphase: Spindle fibres push chromo­somes to equator (middle) on 2 sides of equator
same no homo
Anaphase: Homo chromo­somes move to opposite sides of cell (spindle fibres pull)
Sister chromatids separate
Telophase: spindle fibres disappear, nuclear membrane comes back, two nuclei form, after telo cell divides at cleavage furrow, 2 cells
Same, cell later divides after, 4 cells
Still Interphase and Cytoki­nesis. Homologous

Binary Fission

Cell splits to two daughter cells with id DNA
Some bacteria reproduce through binary fission cause they don't have a nucleus
Mutation may occur during dna rep. or when chromo­somes don't move to 2 dtr. cells
Prokar­yotic cells only. Barrier forms between daughter cells as they split

Plant Reprod­uction

male rep. org: stamen
female rep. org: pistil
releases m. gamete
gamete carried to stigma
anther: pollen stored­&p­roduced
Stigma: sticky­&c­aptures male gamete
Pollen grains contain male gamete
style: where the pollen tube is
filament supports anther
ovary: contains ovules
 
Ovules: surround female gamete
Seed germin­ation=a seed developing to plant
 

Sexual Reprod­uction

Mating: When sperm & egg meet
Fertil­iza­tion: When gametes fuse to form zygote
Develo­pment: When organism develops into embryo
Embryo: is unborn­/un­hatched offspring in develo­pment process
Fertil­iza­tion: sperm breaks into egg cell and penetrates the cell membrane, then fusses with egg nucleus making zygote
Internal fertil­ization gametes join outside of parents.
External is when gametes join inside parents, embryo inside mom
Internal:
 
External:
Embryo is protected
 
Not protected
More energy
 
little energy
Produces less
 
Produces more
More compet­ition for food
 
Less compet­ition
More likely to survive
 
Many are not fertilized
Zygote eventually turns into embryo, which eventually makes a complete individual
Morula­>Bl­ast­ula­>Ga­strula
Morula= End of week 1 (ball of cells) Blastula= End of week 2 (hollow ball of cells, cells can develop into any type of cell) Gastrula= 3 distinct layers of cells (Ectoderm= skin & nerves, Mesoderm= Muscles & bones, Endoderm= lungs, liver, and digestive system lining)
Gamete­s=s­per­m/egg. Sperm cells have flagella & are mobile

Asexual vs Sexual Reprod­uction

Rep. Purpose: Produce a offspring, continue species
Cell Theory: "New cells are formed through the division of existing cells."­
Every species has different method of rep.
Asex. rep.
sex. rep.
Asex. 0->0 0 (parent is now daughter cell)
Sex. 0+0= 0 (Zygote) (parents usually stay alive)
1 Parent
2 parents/ Gametes= sperm, egg
All parent DNA
Offspring geneti­cally different/ Half Dad DNA, Half Mom DNA
Geneti­cally Identical
Genetic diversity= better immunity
Clones are natural, but can also be artificial
DNA is made of many nucleoids liked together
4 types of nucleoids: Adenin­e-T­hym­ine­,Cy­tos­ine­-Gu­anine
DNA coil into condensed form: chromatin
More condensed to chromo­some, when the cell is ready to reproduce
DNA looks like long spiral ladder called double helix
Sides of ladder are made up of sugar & phosphate
If the genetic code messes up it causes genetic mutation.
 

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