Sexual+and+Asexual+reproduction

Expert number 3 can add information here about Asexual and Sexual reproduction

Jennifer morrissey group 7 Since this is for primary school i chose text and pictures that i thought could be used for this type of cohort. Group 1 - Kathryn Kypr Asexual reproduction only requires one organism while sexual reproduction requires both a male and female to produce offspring. Some organisms can reproduce both asexually and sexually, like coral and the Komodo dragon. However, if they continually use the asexual method over several generations, problems will occur with their ability to adapt to their environment as there is no genetic variation in their genes to pass along. Cahill & Spence (2003, p. 70) state that ‘there are five methods of asexual reproduction: budding, vegetative propagation, fragmentation, spores and fission’. Method of reproduction
 * Expert group member 3 **
 * Asexual reproduction **
 * Fission -parent cell splits into two identical parts (one celled organisms such as protozoa or bacteria).
 * Fragmentation – similar to fission but in multi-cellular organisms (eg. worms)
 * Budding – occurs in both single and multi-cellular organisms (grows off parent to become an individual)
 * Spores – contain numerous reproductive cells which grow new individuals
 * Vegetative propagation – reproduce asexually and sexually by growing parts (runners) which separate from parent plant to form individual plant
 * 1) Nucleus divides
 * 2) Each chromosome is copied
 * 3) Each nucleus receives the same genetic material (DNA)
 * 4) Cell divides into two
 * 5) Resulting cells are exact copies of one another.



Animals (including us) also use this process during normal growth and development and when tissues are being replaced during illness or injury. As there is no new genetic material being introduced, these cells can be described as clones.

Cahill & Spence (2003) surmise that after the sperm has fertilized the egg, the offspring has the characteristics of both parents and will have different features from their siblings (accept for identical twins). Sexual reproduction therefore produces unique variations into offspring which is essential for evolutions to occur.
 * Sexual reproduction **
 * 1) Sperm (animals) or pollen (plants) fertilize egg (animal) or ovules (plant)
 * 2) Cell division occurs which halve the number of chromosomes in each resulting cell
 * 3) Chromosome separation process ensures each sex cell has a unique combination of genes from both specimens in its nucleus
 * 4) Egg then divides over and over using the normal process of cell division (clones)
 * 5) Cells begin to specialize as embryo/seed develops (only read ½ of genetic material)
 * 6) At this point they lose the ability to divide into other cell types; however unspecialized cells such as stem cells still retain the ability to change.


 * Comparison chart **
 * || ** Asexual Reproduction **  ||  ** Sexual Reproduction **  ||
 * Number of organisms involved || One parent needed || Two parents are required to mate ||
 * Cell division || Cells divide by Fission, budding, or regeneration || Cells divide by Meiosis ||
 * Types || Budding, vegetative reproduction, fragmentation, spore formation || Syngamy and conjugation ||
 * Advantages || Time Efficient; no need to search for mate, requires less energy || Variation, Unique., organism is more protected ||
 * Disadvantages || No variation - if the parent has a genetic disease, offspring does too. || Requires two organisms, requires more energy ||
 * Evolution || There is very little chance of variation with asexual reproduction. Mutations in [|DNA] can still occur but not nearly as frequently as in sexual reproduction. || Sexual reproduction leads to genetic variation in new generations of offspring. This is fundamental to evolution. ||
 * involvement of sex cells || no formation or fusion of gametes(sex cell) || formation or fusion of gametes(sex cell) occurs ||
 * found in || lower organisms || higher invertebrates and all vertebrates ||
 * unit of reproduction || may be whole parent body or a bud or a fragment or a single somatic cell || gamete ||
 * time period || less || more ||
 * number of offsprings produced || two(minimum) or more than two || one(minimum) or more than one ||

Information sources Biotopics.co.uk - [] Cahill, J., Spence, R. (2003). //Heinemann science 2 for Western Australia//; an outcomes based approach. Diffen - []