Table Talk What are at least 2 reasons why cells must divide? Use any/all notes so far from today or yesterday and TALK about the following questions with everyone at your table. Then, select one person to share OUT LOUD for each question…3 different people! What are at least 2 reasons why cells must divide? How is cell division different for prokaryotes and eukaryotes? What happens to the DNA of all cells before a cell can divide?

Introduction to Cell Reproduction Asexual Reproduction

What is CELL REPRODUCTION? The process of making new individual organisms.

REPRODUCTION Reproduction is different for Prokaryotes and Eukaryotes. There are 2 main types of reproduction: ASEXUAL –both prokaryotes and eukaryotes SEXUAL – only eukaryotes Let’s take a closer look!

2 Types of Reproduction ASEXUAL REPRODUCTION SEXUAL REPRODUCTION Process where 1 parent cell divides and produces genetically identical offspring. Also called CLONING! A new organism is created by combining the genetic material of 2 organisms in a process that starts with meiosis, a type of cell division. Occurs only in eukaryotes.

Types of Asexual Reproduction in Prokaryotes Binary Fission Bacteria divide into 2 equal and identical parts NOTICE: BEFORE the cell divides, the DNA is replicated!!!

Types of Asexual Reproduction in Eukaryotes 1. Binary Fission Unicellular (single-celled) organisms divide into 2 cells

Types of Asexual Reproduction in Eukaryotes 2. Budding Unicellular organisms like yeast and protists divide into 2 identical cells

Types of Asexual Reproduction in Eukaryotes 3. Vegetative Propagation Asexual reproduction in plants. Parent organism Genetically Identical Offspring

Types of Asexual Reproduction in Eukaryotes 4. Spore formation Many multicellular organisms like ferns use spores during their life cycle

5. Regeneration Replacement, renewal or re-growth of lost or damaged body parts; common in invertebrates

Types of Asexual Reproduction in Eukaryotes All use MITOSIS!

ASEXUAL or SEXUAL? Complete the chart as we view and discuss the next 7 pictures of organisms reproducing.

SEXUAL or ASEXUAL? Budding Yeast Budding– daughter cells pinches off parent cell For each mitotic division, a genetically identical copy of the parent is made, for a total of 2 cells

SEXUAL or ASEXUAL? Budding Hydra Budding– daughter cells pinches off parent cell – a genetically identical copy of the parent is made

SEXUAL or ASEXUAL? Bacteria Reproducing Binary Fission – splitting in half Parent bacteria splits to make a genetically identical offspring End result is 2 identical cells

SEXUAL or ASEXUAL? Pine Tree Reproduction Cones produce pollen which are sex cells (plant sperm) Some cones produce ovules (eggs) Pollen and eggs join during fertilization 2 parent pine cones will combine their genetic material to make a new genetically different (but similar) plant

SEXUAL or ASEXUAL? Flowering Plant Reproduction Af SEXUAL Flowers contain both pollen (sperm) and ovules (eggs) which are sex cells. These are also called gametes. During fertilization - 2 sets of DNA combine to make the new (genetically different, but similar) flower

SEXUAL or ASEXUAL? Peacock and Peahen Peahens produce eggs and peacocks produce sperm. The sperm will fertilize the egg and produce a zygote, which will grow into an embryo. 2 parent peacocks will combine their genetic material to make a new, genetically similar, but different bird

SEXUAL or ASEXUAL? Binary Fission of Paramecium Binary Fission – splitting in half A single parent protist splits to make one new genetically identical offspring Total cells at the end = 2

One extra …SEXUAL or ASEXUAL? Mushroom Sporulation The mushroom produces spores which grow into genetically identical offspring

Drawing Conclusions Noticing Trends? What general conclusions can you draw about reproduction in plants? What general conclusions can you draw about reproduction in animals? What general conclusions can you draw about reproduction of simpler, unicellular organisms such as bacteria, yeast, and hydra?

Complete the Chart Characteristic Asexual Sexual Number of parent cells involved Genetic outcome of offspring How many offspring produced? How fast are offspring produced? Main mode of reproduction for organisms like…

2 final questions… If a population needed to adapt to a changing environment by taking advantage of a diverse gene pool, which mode of reproduction would be most useful/advantageous [sexual or asexual] Why? If a population needed to spread out and colonize a large area very quickly, which type of reproduction would be most advantageous?