Major Types of Reproduction

1. Major Types of Reproduction Mr. Hollander’s 8th Grade Science Class

2. What is Reproduction??? • Reproduction is the biological process by which new organisms (offspring) are produced (parent{s}) • It is a fundamental feature of all known life and every individual organism exists as the result of reproduction • There are two main types of reproduction: • Asexual Reproduction • Sexual Reproduction

3. “It Takes One to Make a Thing Go Right” • Asexual reproduction occurs when an individual can reproduce without involvement with another individual of that species • The offspring will be genetically the same as the parent (a copy) because there is no genetic material from another individual • Most organisms that reproduce asexually are simple in nature • Some examples include: • Bacteria - Binary Fission • Single-Celled Organisms - Mitosis • Fungus – Spores • Starfish – Fragmentation

4. Asexual Reproduction The Good… The Bad… Offspring are genetic clones and a negative mutation can make organisms susceptible to disease/death The offspring can be close together and compete for resources Slow reaction to environmental changes and temperatures can quickly wipe out populations • It is faster in producing offspring when conditions are favorable • It is easier and uses very little energy as there is no finding of an acceptable mate • It is more reliable because there are less steps and less that can go wrong

5. Asexual Reproduction and Mitosis • Mitosis is a step by step process in which a cell divides itself in half to make two identical copies • There are a total of six phases of mitosis • It is important to realize that during mitosis the chromosomes/genetic material doesn’t change but is simply a copy of the original

6. Asexual Reproduction Video

7. “It Takes Two to Make a Thing Go Right” • Sexual reproduction is the creation of an offspring by combining the genetic material of two organisms • The offspring that is created inherits genetic material from each parent and is genetically different from both parents • Sexual reproduction is the primary method of reproduction for the majority of animals and plants • It is believed that sexual reproduction evolved so that organisms could rapidly respond to changing environments and compete for limited resources

8. Sexual Reproduction The Good… The Bad… It requires two healthy organisms to create a healthy offspring It is more complicated due to additional stages in the process of fertilization of the two sex cells; or gametes Sexual reproduction requires more energy than asexual reproduction • More genetic variation allows for adaptations to occur more rapidly and change with the environment • Sexual reproduction creates a more diverse population of offspring and leads to a “survival of the fittest” outcome • Creates new traits that can remove weaknesses within the species

9. Sexual Reproduction and Meiosis • In meiosis, through a series of steps, one complete cell is divided into four cells with ½ the number of chromosomes present in the original cell • These cells created through meiosis serve as sex cells, or gametes • Two gametes, through fertilization, fuse together and each contributes one half of the set of chromosomes needed for the new offspring’s genotype

10. Sexual Reproduction Video

11. What You Need To Know In Review • Reproduction is the biological process by which new organisms (offspring) are produced (parent{s}) and is essential to all forms of life • Asexual reproduction involves one individual and produces an offspring that is identical to the parent and involves the process of mitosis • Positives: Fast, Easy and Reliable • Negatives: Negative Mutation Stays Around, Competition in Small Area, Slow to Change • Sexual reproduction involves two organisms and produces an offspring that is genetically different from that of the parents and involves the process of meiosis • Positives: Genetic Variation, Rapid Change with Environmental Features, Removes Weaknesses • Negatives: Requires Two Organisms, More Complex, More Energy

12. The End!!!