Ch.8- Cellular basis of Reproduction and Inheritance

We all started out as one cell, how did we become more? Cell division from the original cell Is this type of division sexual or asexual? Asexual, because each new cell is identical to the original

When a Seastar grows back an arm what type of division does it require? Asexual What type of reproduction is required to produce Sea star sperm or eggs? Sexual - the sperm or eggs are not identical to the original cell

This is a picture of the stages of development of a Sea Star embryo

What type of reproduction is this ameba doing? Asexual - both cells are identical and will lead to 2 new ameba What do you think “like begets like” means? It means people make more people and sea stars make more sea stars, people can’t make sea stars

How do people reproduce more people? Through sexual reproduction What is the benefit to reproducing sexually over asexually? Variety - sexual reproduction does not produce clones (exact duplicates) of the parents

What type of organism is pictured on the right? Prokaryote-Bacteria What type of reproduction is this? Asexual-binary fission

What are the spaghetti like things in the cell? Chromosomes What has to happen to them before the cell can divide? It must be duplicated

How are genes carried in a cell? On a chromosome What are chromosomes made of? Protein and DNA called chromatin When the chromosome’s DNA is duplicated the chromosome is then made up of two ______ ________ Sister Chromatids

What is the longest stage of the cell cycle? Interphase When is the DNA replicated? Interphase Mitosis means the splitting of the nucleus, what does cytokinesis mean? The division of the cytoplasm

Mitosis has 4 stages what are they? Prophase, metaphase,anaphase and telophase (PMAT) What is happening during these stages? The sister chromatids are lining up in the middle of the cell and separating When did the sister chromatids get made? Interphase (S phase)

What is happening during the three stages of interphase? G1 = gap1 supplies are increased S = DNA copied creating two sister chromatids G2 = proteins synthesis for mitosis

At what stage of mitosis are the chromosomes first visible? Prophase What stage of the cell cycle is the longest? Interphase

What phase is shown on the right? Metaphase

Cleavage What does cleavage mean? Separation What is happening when a cleavage furrow forms? The cell is separating into two. What type of cells form cleavage furrows during cytokinesis? Animal

What types of cells form cell plates during cytokinesis? Plant

What do you notice about these cells growth when some cells are taken away? They never grow on top of each other, they stop dividing when the dish has one layer.

What happens when those cells become cancerous? They don’t stop growing and create a tumor

What is the purpose of the checkpoints in the cell cycle? They are like built-in brakes to keep the cell from reproducing when it shouldn’t What types of chemicals can switch the G1 checkpoint on? Growth hormones

What type of process is it when a hormone signals the cell to do something? Signal transduction What happens if a cell does not get growth factor? It will probably stay in interphase How the cell How the cell cycle works

What causes cancer cells to grow out of control? Their checkpoints are not working What is the difference between a malignant tumor and a benign tumor? Malignant tumors continue to divide and pieces can break off and spread to other parts of the body. Benign tumors usually stop growing on their own and do not spread

Cancer animations More animations More What is the difference between a carcinoma and a sarcoma? Carcinoma is a cancer of the coverings of the body like skin cancer, sarcoma is cancer of the tissues like bone and muscle

What is the difference between these two mamograms? The bottom picture shows a tumor

Review What are the purposes of mitosis? Growth as seen in the root tip of a plant Repair Asexual reproduction as seen with the budding hydra