Bell Work Take a “Notes Sheet” handout from the lab counter and on the blank back side, respond to the following scenario: Imagine you are the last person alive on Earth, and clinging to your skin is the last bacterium alive on Earth. Eventually, you both will die. Is it possible that humans or bacteria will ever populate the Earth once again? If so, which of you will be able to reproduce offspring and why?

Asexual Reproduction RHLT2: I can explain the difference between asexual and sexual reproduction and discuss the advantages and disadvantages of each. 7 th Grade ScienceMrs. Jerolaman

Asexual vs. Sexual Reproduction AsexualSexual

Asexual Reproduction- Budding  Offspring develops on the parent (as an outgrowth or “bud”) then later detaches  Offspring develops by mitosis

Asexual Reproduction- Regeneration  Offspring develops from a fragmented piece of the parent  Vegetative Regeneration (Propagation): plant offspring sprout from cuttings, runners, roots, etc.  Must create at least 2 independent organisms from 1, not just a new part.

Regeneration cont. Regrowth of parts through mitosis IS regeneration but NOT asexual reproduction (still only 1 organism)

Asexual Reproduction- Fission  Parent (usually a unicellular organism) divides in half to form 2 (equal-sized) offspring  “Binary Fission” = Prokaryotic cell division!!! This means NO MITOSIS  Mitosis occurs in Eukaryotic organisms E. Coli

Pros and Cons Advantages  Do not have to wait for a mate  Solitary or stationary organisms (organisms that live alone or do not move) can reproduce  Quick and efficient  Immunity is passed from parent to offspring Disadvantages  No variety in offspring  Identical offspring are vulnerable to the same diseases  Mutations or unfavorable characteristics will carry from parent to offspring

Before you leave… On the provided piece of paper, tell me your thoughts in response to the following question, “If humans reproduced asexually, how might your life be different?” Great job and have a wonderful day!!!