PART 1 : Asexual vs. Sexual Reproduction [ 4 marks ]
- Discuss the differences between, and the advantages and disadvantages of sexual and asexual reproduction :
SEXUAL REPRODUCTION
Sexual Reproduction is the formation of a new organism from two parents usually, and involves the joining of gametes [ e.g. sperm, pollen, egg] to form a single cell called a zygote [ or fertilised egg ]. The offspring are similar, but not identical to the parents. Sexually Reproductive organisms include mammals, most reptiles, and flowering plants. ADVANTAGES
There is greater genetic variation of the offspring and therefore, greater chance of survival in changing environments. Asexual Reproduction is the process by which a single organism produces a new organism identical to itself. An asexually reproducing organism does not require a partner to produce offspring. It is a process that requires no fusion of gametes whatsoever. Asexually Reproductive organisms include bacteria, nonflowering plants and some reptiles. DISADVANTAGES
Some disadvantages of sexual reproduction are the facts that it requires 2 parents, so if one species dies out, they can no longer reproduce. Sexual reproduction also poses risks of mutations and hereditary diseases. Sexual reproduction is also not as rapid as asexual reproduction. Energy is also expended in finding a mate in many organisms. However some organisms have both male and female reproductive organs that are able to produce gametes simultaneously.
ASEXUAL REPRODUCTION
Asexual reproduction is the formation of a new organism when there is the presence of a single parent and no joining gametes [ e.g. sperm, pollen, egg ]. The offspring has identical genes and chromosomes to the parent. ADVANTAGES
No energy is expended in finding a mate. there is a high chance of survival of the offspring, if the offspring remains near the parent in a stable environment. DISADVANTAGES
Less genetic diversity gives the offspring
Bibliography: www.google.com www.wikipedia.com.au www.emedicine.medscape.com/article/263907-overview [ Article One ] www.nytimes.com Nelson Biology VCE Units 1&2 Encyclopaedia Brittanica