Sexual Vs. Asexual Reproduction

Sexual vs. AsexualReproduction

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DNA – what is it and how does it work? Every cell in your body has a job – there are over 200 cell types in the humanbody that means over 200 jobs! How does each of these cells know exactly what job to do? DNA Set of instructions or a blueprint for each cell Made up of 4 bases (A, G, T, C) T - A G - CDNA coding Two sides to DNA double helix – match to each otherSide one - ATG CGT GGT CAG TCG ATA TAT GGC CCCSide two - TAC GCA CCA GTC AGC TAT ATA CCG GGG

Chromosomes hold all of your DNA DNA is packaged tightly and organized intochromosomes Chromosomes hold the needed codes forcharacteristics like hair color, eye color, height All cells in an organism have the same set ofchromosomes Chromosomes exist in pairs One from mother, one from father Humans have 23 pairsEach chromosome pair codes for characteristics Codes interact with each other – some dominant, some recessive

Purpose of Reproduction Produces offspring Continues genetic line Increases population of the species

Types of Reproduction Asexual Offspring arise from a single organism offspring are genetic copies of the parentSexual Offspring arise from two parent organisms offspring are a genetic mix of half the mother’s DNA and half the father’s DNA

Asexual Reproduction Organisms that reproduce asexually: Single-cell Organisms Bacteria Protists AmoebasSome multi-cellular Organisms Starfish Fungi Sea anemones Coral

How does Asexual Reproduction work? Mitosis – process makes exact copy of DNA Cell copies its chromosomes and splits Creates a cell exactly like the original Parent OffspringTWOIDENTICALCELLSPARENT CELLCOPIES CHROMOSOMESSPLITTING APART

Video on Asexual Reproduction/Mitosis Be amazed and enriched by the carefully selected and very important video!

Advantages vs. DisadvantagesADVANTAGESDISADVANTAGES FAST PROCESS LACK OF GENETIC VARIATION POPULATION GROWS QUICKLY VULNERABLE TO EXTINCTION IF ENVIRONMENTCHANGES ONLY ONE PARENT NEEDED no need to find mate LITTLE ENERGY REQUIRED IF PARENT HAS ISSUE (BAD TRAIT) – OFFSPRINGHAS ISSUE

Sexual Reproduction Organisms the reproduce sexually: Most: Mammals Fish Reptiles Birds Insects

How does Sexual Reproduction work? Meiosis – process that makes sex cells (“gametes”) – cells that only have halfthe chromosomes of the cells of the parents Cell copies its chromosomes and splits Cells then split AGAINCreates 4 cells that have halfthe chromosomes of theoriginal cell These 4 cells are called GAMETES Sex cells – eggs or spermEgg and Sperm come together ½ ½ whole cellORIGINAL CELLFIRST SPLITCOPIES CHROMOSOMESSECOND SPLIT

Video on Sexual Reproduction/Meiosis Be amazed and enriched by the carefully selected and very important video!

Advantages vs. DisadvantagesADVANTAGESDISADVANTAGES GENETIC VARIATION WITHIN SPECIES combination of sperm and eggcreates variety REQUIRES A LOT OF ENERGY AND TIME LESS LIKELY TO GO EXTINCT more likely to have traits that allow foradaptation POPULATION GROWS SLOWLY ALLOWS FOR EVOLUTION AND SURVIVAL OFSPECIES HAVE TO FIND/ATTRACT A MATE

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Meiosis –process that makes sex cells (“gametes”) –cells that only have half the chromosomes of the cells of the parents Cell copies its chromosomes and splits Cells then split AGAIN Creates 4 cells that have half the chromosomes of the original cell These 4 cells are called GAMETES Sex cells –eggs or sperm