Hereditary and Asexual Reproduction Flashcards
Asexual Reproduction
Creating a clone of oneself by:
1. Binary fission (e.g. bacteria)
2. Budding (e.g. hydra)
3. Fragmentation (e.g. star fish)
Pros and Cons of Asexual Reproduction
Advantages: no need for a mate, no energy needed to court a mate, rapid increase in population
Disadvantages: offspring are genetically identical, if environment changes - whole population could die
Cloning
Process of forming a genetically identical offspring from a single cell or tissue –> can be natural (e.g. mitosis, grafting) or created by humans (e.g. biotechnology)
Animal Cloning
In 1996, Dolly the sheep was created (since then: goats, cows, rats, etc.)
A body cell from an adult sheep was fused using electric shock to an unfertilized egg lacking a nucleus from a second donor - resulting embryo implanted into third sheep for incubation (two cells and three sheep needed in total)
Problems with Cloning
Do not live as long as normal organisms
Suffer from variety of health conditions (Dolly died prematurely of a lung disorder)
Have signs of premature aging like arthritis
Genetically Modified Organisms
Cloning used to move genes from one species into another (ex. human insulin put into safflower plants to grow insulin) - other: spider goats, vaccine bananas, glow-in-the-dark mice, etc.
Cloning Endangered Species
230 plants and animals in Ontario alone are endangered - captive breeding programs are starting to make use of cloning –> In 2009, the extinct spanish ibex was cloned, however, it died of lung defects
Why Not Clone Endangered Species?
- Egg harvest is challenging - requires extensive knowledge on the reproductive system of an animal
- Loss of genetic diversity (whole population of inbreeding) - more susceptible to genetic disorders
- Won’t solve root of problems - poaching, habitat destruction, etc.