Biology+Unit+Three+Review+2023 (1).docx

**Unit Three** **Conceptual Understanding:** Cells are the basic units of all organisms, both prokaryotes and eukaryotes. Prokaryotic and eukaryotic cells differ in key structural features, but both can perform all functions necessary for life. **BIO.1C: Students will relate the diversity of organ...

**Unit Three** **Conceptual Understanding:** Cells are the basic units of all organisms, both prokaryotes and eukaryotes. Prokaryotic and eukaryotic cells differ in key structural features, but both can perform all functions necessary for life. **BIO.1C: Students will relate the diversity of organelles to a variety of specialized cellular functions.** ***Eukaryote vs Prokaryote***  ***\*a nucleoid is a region in a prokaryote where the DNA is located. It is not encased, so the DNA is exposed.*** +---------+---------+---------+---------+---------+---------+---------+ | Kingdom | Example | Cell | Number | Importa | Mode of | | | | | type | of | nt | nutriti | | | | | | cells | structu | on | | | | | | | res | | | +=========+=========+=========+=========+=========+=========+=========+ | Eubacte | *E.coli | Prokary | Unicell | Peptido | Autotro | | | ria | * | ote | ular | glycan | ph | | | | | | | in cell | or | | | | *Strept | | | wall; | heterot | | | | ococcus | | | | roph | | | | * | | | Nearly | | | | | | | | no | | | | | | | | interna | | | | | | | | l | | | | | | | | organel | | | | | | | | les | | | | | | | | (except | | | | | | | | for | | | | | | | | ribosom | | | | | | | | es) | | | +---------+---------+---------+---------+---------+---------+---------+ | Archaeb | Halophi | Prokary | Unicell | NO | Autotro | | | acteria | les | ote | ular | Peptido | ph | | | | | | | glycan | or | | | | Thermop | | | in cell | heterot | | | | hiles | | | wall; | roph | | | | | | | | | | | | | | | Nearly | | | | | | | | no | | | | | | | | interna | | | | | | | | l | | | | | | | | organel | | | | | | | | les | | | | | | | | (except | | | | | | | | for | | | | | | | | ribosom | | | | | | | | es) | | | +---------+---------+---------+---------+---------+---------+---------+ | Protist | Amoebas | Eukaryo | Some | Nucleus | Autotro | | | s | | te | unicell | with | ph | | | | Paramec | | ular; | many | or | | | | ium | | some | membran | heterot | | | | | | multice | e | roph | | | | | | llular; | bound | | | | | | | colonia | organel | | | | | | | l | les; | | | | | | | | | | | | | | | | Cell | | | | | | | | wall | | | +---------+---------+---------+---------+---------+---------+---------+ | Fungi | Yeast | Eukaryo | Some | Nucleus | Heterot | | | | | te | unicell | with | roph | | | | Mushroo | | ular; | many | | | | | ms | | | membran | | | | | | | Some | e | | | | | | | Multice | bound | | | | | | | llular | organel | | | | | | | | les; | | | | | | | | | | | | | | | | Cell | | | | | | | | wall | | | | | | | | with | | | | | | | | chitin | | | | | | | | | | | | | | | | NO | | | | | | | | Chlorop | | | | | | | | last | | | +---------+---------+---------+---------+---------+---------+---------+ | Plants | Mosses | Eukaryo | Most | Nucleus | Autotro | | | | | te | multice | with | ph | | | | Grasses | | llular; | many | | | | | | | very | membran | | | | | Trees | | few | e | | | | | | | unicell | bound | | | | | | | ular | organel | | | | | | | (green | les; | | | | | | | algae) | | | | | | | | | Cell | | | | | | | | wall | | | | | | | | with | | | | | | | | cellulo | | | | | | | | se | | | | | | | | | | | | | | | | Chlorop | | | | | | | | last | | | +---------+---------+---------+---------+---------+---------+---------+ | Animals | Insects | Eukaryo | Multice | Nucleus | Heterot | | | | | te | llular | with | roph | | | | Vertebr | | | many | | | | | ates | | | membran | | | | | | | | e | | | | | | | | bound | | | | | | | | organel | | | | | | | | les; | | | | | | | | | | | | | | | | NO Cell | | | | | | | | wall | | | | | | | | and NO | | | | | | | | Chlorop | | | | | | | | last | | | | | | | | | | | | | | | | Centrio | | | | | | | | les | | | | | | | | for | | | | | | | | animal | | | | | | | | cell | | | | | | | | divisio | | | | | | | | n | | | +---------+---------+---------+---------+---------+---------+---------+ - *Remember, **viruses lack all of the features of living things**. They do not have the cellular machinery to replicate, thus the need to hijack a host cell and use the ribosomes and other structures of the host to replicate.* **Conceptual Understanding:** The structure of the cell membrane allows it to be a selectively permeable barrier and maintain homeostasis. Substances that enter or exit the cell must do so via the cell membrane. This transport across the membrane may occur through a variety of mechanisms, including simple diffusion, facilitated diffusion, osmosis, and active transport. **BIO.1D: Students will describe the structure of the cell membrane and analyze how the structure is related to its primary function of regulating transport in and out of cells to maintain homeostasis.** - ***When we covered the fluid mosaic model of the cell membrane, we explained that the phospholipid bilayer is made of many smaller and moveable parts.*** - ***We also explained that because phospholipids have hydrophobic tails, the means by which some materials move across the membrane is selectively permeable (meaning that some material can get through, but others cannot) because some materials cannot interact with those hydrophobic tails. Some materials can only enter through special channel proteins or pores. Some materials, due to their size or nature, cannot enter the cell.*** - ***For example, glucose can be moved into the cell by using special channels within the cell membrane, but starch cannot be moved out of cell because it is just too big.*** - ***One definition that was covered to help you remember selectively permeable: Transporters [(transport proteins)]: selective; only lets certain substances through.***   ***Simple diffusion-** The movement of particles from an area of high concentration to an area of low concentration, **DIRECTLY across the membrane**, without the use of energy.* ***Facilitated diffusion-** The movement of particles from an area of high concentration to an area of low concentration, **BY MEANS OF A TRANSPORT PROTEIN across the membrane,** without the use of energy.* ***Active transport-** uses energy (ATP) to move materials either with OR against their concentration gradient by means of special channels or pumps.* ***BIO.1D.2:** Develop and use models to explain how the cell deals with imbalances of solute concentration across the cell membrane (i.e., hypertonic, hypotonic, and isotonic conditions, sodium/potassium pump).*  - Plants and animals react differently in hypertonic, isotonic, and hypotonic solutions. Isotonic environments are good for animals because it allows for normal **movement of** **water (osmosis)** into and out of the cell, creating an isotonic environment. - Plants prefer hypotonic solutions because as water enters the cell, the cell membrane presses against the cell wall, causing the plant to be more rigid and stand upright (turgid). When water moves through osmosis, it moves from areas of higher water concentration to areas of lower water concentration. When there are more solutes in the water**, water will move from higher concentrations of WATER to lower concentrations of WATER.** When you drink a lot of salt water, your cells will lose water because your cells have less solutes in them compared to the salt water that you drink. This would cause you to dehydrate even faster. **Conceptual Understanding:** Cells grow and reproduce through a regulated cell cycle. Within multicellular organisms, cells repeatedly divide for repair, replacement, and growth. Likewise, an embryo begins as a single cell that reproduces to form a complex, multicellular organism through the processes of cell division and differentiation. **BIO.1E: Students will develop and use models to explain the role of the cell cycle during growth, development, and maintenance in multicellular organisms.** - *If a cell is not specialized, it is called a stem cell.* - *Stem cells are influenced by the cells around them to differentiate and specialize.* - *If a cell is specialized, it is referred to as differentiated.* - ***NOTE: Prokaryotes do not specialize. They only are one cell, so that cell needs to be able to perform all cellular tasks.*** - *Degrees of stem cells differentiation* - *Totipotent- can differentiate into anything.* - *Pluripotent- can differentiate into most cell types.* - *Multipotent- can only differentiate into a few cell types.*  - *Reread the section on the **cell cycle** with regards to what happens in each phase.* There are mechanisms that control when the cell is supposed to leave G1 of interphase. The most common are: - ***Growth factors***- encourage growth and cell division (outside the cell) - ***Cyclins***-promote mitosis after a certain concentration of the protein is met (Maturation Promoting Factor). (Inside the cell) - ***In cancer, there is no G1, and mitosis is not regulated anymore***. he Cell Cycle, Mitosis and Meiosis --- University of Leicester - Check the cell cycle notes for the diagrams of mitosis. The cell cycle goes in this order: \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_Interphase\_\_\_\_\_\_\_\_\--\>\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Mitosis\_\_\_\_\_\_\_\_\_\_\_\_\_ \-\--\>cytokinesis \-\--\> repeat G1, then S (DNA COPIED), then G2 \-\--\>Prophase, metaphase, anaphase, telophase \-\--\> cytokinesis \--\> G1 - *These cells are still going through **asexual reproduction**. Budding (some simple animals), vegetative propagation (some plants), regeneration (like skin cells), binary fission (bacteria).* - ***Since asexual reproduction produces clones, clones are exact copies of their parents.** Thus, if a cell makes an exact copy of its DNA during the s-phase of interphase and divides from one cell into two cells, then the two cells produced are identical in their DNA because there is no genetic recombination (no sperm or egg) here.*