Fichas
1.1 Cell Biology | IB Biology HL
Fichas del conjunto (32)
- 1State the 3 principles of cell theoryThe cell theory states that:
1. All living things are composed of cells
2. The cell is the smallest unit of life
3. All cells arise from pre-existing cells - 2List 3 atypical examples that question cell theory.Certain types of cells/tissues do not conform to a standard notion of what constitutes a cell:
1. Striated muscle cells
2. Aseptate fungal hyphae
3. Giant algae - 3Discuss how Striated Muscle Cells differ from typical cells.- Muscle cells fuse to form fibres that may be very long (>300mm). (Much larger than a typical cell)
- Have multiple nuclei despite being surrounded by a single, continuous plasma membrane.
- Challenges the idea that cells always function as autonomous units & that cells have one nucleus. - 4Discuss how Aseptate Fungal Hyphae differ from typical cells.- Aseptate fungal hyphae are long threads (hyphae) w/ many nuclei, but no dividing cell walls (septa/septum)
- Challenges the idea that cells are a single unit, as it is multinucleate, very large, & possesses a continuous cytoplasm.
- 5Discuss how Giant Algae differ from typical cells.- Gigantic size (b/n 0.5 - 10cm in length)
- Has complex parts (3 parts: bottom rhizoid, stalk, & top umbrella that may fuse into a cap).
- Challenges the idea that cells are simple in structure & small in size.
- 6List & explain the functions of life.MR SHENG
- Metabolism: Enzyme-catalysed chemical reactions that take place w/i the cells of living organisms.
- Reproduction: The production of offspring, either asexually/sexually, to pass on genetic information to the next generation. Reproduction ensures the survival of the species.
- Sensitivity/Response (to a stimulus): Living things respond to changes in their internal & external environment.
- Homeostasis: Maintenance of a constant internal environment by regulating internal cell conditions.
- Excretion: Removal of waste products from metabolism & other toxic materials.
- Nutrition: Living things exchange materials & gases with the environment.
- Growth: Living things can move & change shape or size
- 7Describe the Paramecium- Eukaryotic organism
- Unicellular
- Heterotroph - 8—
- 9State & explain the functions of life in a Paramecium (referring to its structures).- Metabolism (food vacuole/cytoplasm): Food particles are enclosed w/in small vacuoles that contain enzymes for digestion. Most metabolic pathways occur in the cytoplasm.
- Reproduction (macronucleus & micronucleus): Paramecia often divides asexually (fission) to form two new daughter cells. Macronucleus splits by a type of amitosis, & micronuclei undergo mitosis.
- Sensitivity/Response (cilia): Paramecia are surrounded by small hairs called cilia which allow it to move towards food.
- Homeostasis (cell membrane): Essential gases enter (e.g. O2) and exit (e.g. CO2) the cell via diffusion.
- Excretion (: Solid wastes are removed via an anal pore, while liquid wastes (e.g water) are pumped out via contractile vacuoles.
- Nutrition (cell mouth/cytostome): Paramecia engulf food via the cytostome.
- Growth: After consuming food, the Paramecium will get larger until it divides. - 10Contrast Unicellular & Multicellular organisms w/ examples of both.Unicellular: An organism composed of a single cell.
e.g. Paramecium, Amoeba, etc.
Multicellular: An organism composed of multiple cells.
e.g Turtle, Oak tree, Human - 11Describe the Chlorella- Eukaryotic cell
- Unicellular
- Autotroph - 12—
- 13State & explain the functions of life in a Chlorella (referring to its structures).- Metabolism (chloroplast): Chlorophyll pigments allow organic molecules to be produced via photosynthesis.
- Reproduction: The nucleus divides to support cell division via mitosis.
- Sensitivity/Response: Cilia move the chlorella in response to changes in the environment e.g. towards light
- Homeostasis: Essential gases enter (e.g. CO2) & exit (e.g. O2) the cell via diffusion.
- Excretion: Gases & other essential materials exchange via diffusion.
- Nutrition: " "
- Growth: The org. will grow until it divides asexually. - 14State the function of a cell's mass/volume.A cell's rate of metabolism bc larger cells need more energy to carry out processes.
- 15State the function of a cell's surface area.The cell's rate of material exchange bc large membrane surface = more material movement.
- 16Explain what occurs to the volume & surface area of a cell as it grows. State what effect it has on the SA:Vol ratio.As a cell grows, volume (units3) increases faster than surface area (units2), leading to a decreased SA:Vol ratio.
- 17Explain why cells divide.If metabolic rate exceeds the rate of exchange of vital materials and wastes (low SA:Vol ratio), the cell will eventually die.
Therefore, growing cells tend to divide & remain small to maintain a high SA:Vol ratio suitable for survival. - 18State examples of tissues that specialize in gas/material exchange.Intestinal tissue of the digestive tract may form a ruffled structure (villi) to increase the SA of the inner lining.
Alveoli w/in the lungs have microvilli, which function to increase the total membrane surface. - 19State the formula to calculate magnification in drawings/on a micrograph.Magnification = Image size (with ruler) ÷ Actual size (according to scale bar)
- 20Describe the function of a light microscope.- Uses visible light & a combination of lenses to magnify images of specimens.
- Live specimens can be viewed in their natural colour.
- Stains may be applied to resolve specific structures. - 21State what should be included when drawing microscopic structures.- A title to identify the specimen (e.g. name of organism, tissue or cell).
- A magnification/scale to indicate relative size.
- Identifiable structures should be clearly labelled (drawings should only reflect what is seen, not idealised versions). - 22State what is meant by Emergent PropertiesWhen the interaction of components parts produce new functions that individual cells would be unable to perform on its own.
"The whole is greater than the sum of its parts" - Aristotle - 23State the organization of an organism in multicellular organisms. Note: Emergent propertiesCells (basic unit of life) --> Tissue (group of cells working together to perform a specific function) --> Organ (group of tissues working together to perform a specific function) --> Organ system (group of organs working together to carry out the life functions of the complete organism) --> Organism
Overall: Cells --> Tissue --> Organ --> Organ System --> Organism - 24Define DifferentiationThe process during development whereby newly formed cells become specialized by expressing some genes & not others in a cell’s genome.
- 25State what causes cells to differentiate.The activation of different instructions (genes) w/in a given cell by chemical signals will cause it to differentiate
- 26Compare how Active & Inactive Genes are packaged in the nucleus. State the names of the form in which they are packaged.Active genes are usually packaged in an expanded form called euchromatin that is accessible to transcriptional machinery.
Inactive genes are typically packaged in a more condensed form called heterochromatin (saves space, not transcribed). - 27Describe the relationship b/n euchromatin & heterochromatin in differentiated cells.Differentiated cells will have different regions of DNA packaged as euchromatin & heterochromatin according to their specific function.
Genes which help w/ the cell's function will be in the form of euchromatin & expressed, whereas, genes that do not aid in the cell's specialized function will be in the form heterochromatin. - 28State the properties of Stem Cells.Stem cells are unspecialized/undifferentiated cells.
Properties:
1. They can continuously divide & replicate.
2. They have the capacity to differentiate into specialized cell types. - 29Describe the 4 main types of stem cells.1. Totipotent (e.g zygote): Can differentiate into any cell type including placental tissue.
2. Pluripotent (e.g embryonic stem cells): Can differentiate into any cell type.
3. Multipotent (e.g. haematopoeitic adult stem cells): Can differentiate into a number of closely related cell types.
4. Unipotent (e.g muscle stem cells & skin cells): Cannot differentiate, but are capable of self renewal. - 30State the function of Stem Cells.Stem cells can be used to replace damaged/diseased cells with healthy, functioning ones.
- 31Describe the general process of using stem cells for therapeutic use.- Use of biochemical solutions to trigger the differentiation of stem cells into the desired cell type.
- Surgical implantation of cells into the patient’s own tissue.
- Suppression of host immune system to prevent rejection of cells (if stem cells are from foreign source).
- Careful monitoring of new cells to ensure they do not become cancerous - 32Describe Stargart's
Información
- Descripción
- Biologie Fichas sobre 1.1 Cell Biology | IB Biology HL, creado por Risa Kunii el 11/07/2019.
- Creado por
- Risa Kunii
- Visitas
- 72
- Etiquetas
- Valoración