Asexual Reproduction

Reproduction The process by which organisms generate new individuals of the same kind is called reproduction.

Asexual Reproduction The process by which offspring (babies) are made from a single organism. They inherit information only from that “parent”, which means that they are identical to the parent they were made from.

Asexual Reproduction Advantages Disadvantages Only one individual needed Fast Minimal energy required All offspring are identical Hinders diversity More prone to disease/extinction Population control issues

Types of Asexual Reproduction Binary Fission Budding One parent cell duplicates it’s DNA, and then divides into two cells Ex: bacteria An outgrowth on the surface of an organism breaks off, and that piece continues to grow into an adult form Ex: yeast, hydra

Types of Asexual Reproduction Fragmentation Parthenogenesis An organism breaks into two or more fragments, and each fragment grows into an adult form Ex: coral, sea stars An embryo develops from an unfertilized egg Ex: komodo dragons, some invertebrates

Binary Fission Budding

Fragmentation Parthenogenesis

All living things are made of cells.

All cells progress through the cycle at different rates. The Cell Cycle The time when a cell divides to form two daughter cells to the time those cells divide again. All cells progress through the cycle at different rates.

The cell cycle has two main stages. M: cell division Mitosis: division of the cell’s nucleus Cytokinesis: division of the cell’s cytoplasm Interphase cell growth and normal functions chromosomes duplicate cell prepares to divide and there is more growth *Mitosis only occurs if the cell is large enough, and if the DNA is undamaged* Interphase lasts for about 90% of the total time required for the cell cycle.

Mitosis

Mitosis ALL cells (except sex cells) are made by mitosis. In humans, these cells are called somatic cells. Mitosis forms two genetically identical daughter cells. Mitosis is a form of asexual reproduction.

Three important reasons for cell division: Growth = adding more cells to the organism Development = cells become specialized for their function Repair = body heals itself

Interphase The cell is preparing to divide. The DNA is duplicated. Parent cell centrioles spindle fibers nucleus with DNA The cell is preparing to divide. The DNA is duplicated.

This is where the spindle attaches. Prophase The mitotic spindle fibers start to form. The chromatin condenses into chromosomes. The nuclear envelope starts to break down. Each chromosome consists of a pair of sister chromatids that are joined at the centromere. This is where the spindle attaches.

Metaphase Meta = middle! Duplicated chromosomes line up in the middle of the cell. Meta = middle!

Anaphase Sister chromatids separate to opposite sides of the cell.

Telophase Two new nuclei form. Chromosomes begin to uncoil. Mitosis ends.

Cytokinesis Cytoplasm divides to create two separate daughter cells Each new cell has its own nucleus containing identical chromosomes Each surrounded by its own cell membrane

CANCER Free Write: Free Draw: What is cancer to you? How does it relate to what we’ve been talking about in class? What does cancer look like to you?

What is cancer and how does is relate to mitosis? The cell cycle is controlled by the cell cycle control system. Cancer cells have severely damaged cell cycle control systems. These cells divide excessively and exhibit bizarre behavior. A lump created from these cancer cells is a malignant tumor. When these cells spread beyond their original site, it’s called metastasis. Cancer What is cancer and how does is relate to mitosis?