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55 Cards in this Set
- Front
- Back
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What is Cell Theory? |
1. All living things are made of cells 2. Cells are the basic structural and functional unit of organisms 3. All cells are from pre-existing cells |
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How did Robert Hooke contribute to the development of cell theory? |
In 1663, Robert Hooke introduced the term 'cell' |
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How did Robert Brown contribute to the development of cell theory? |
In 1801, Robert Brown discovered the nucleus in cells |
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What is the significance of technological advances to developments in cell theory? |
Without technological advances the cell theory could not have happened. The microscope enabled us to see cells. The staining of the cells enabled division of the nucleus in cell division to be observed. |
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What cell organelles can be seen with a light microscope? (7) |
1. Nucleus 2. Cell Membrane 3. Cell Wall 4. Cytoplasm 5. Chloroplast 6. Vacuole 7. Nucleolus |
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What cell organelles CAN NOT be seen with a light microscope? (5) |
1. Endoplasmic Reticulum 2. Ribosomes 3. Lysosomes 4. Golgi Body 5. Mitochondria |
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What is the function of the NUCLEUS? Can it be found in a plant cell? Can it be found in an animal cell? |
Contains the genetic information of the cell (chromosomes) and controls most of the cell's functioning. Plant - YES Animal - YES |
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What is the function of the CELL MEMBRANE? Can it be found in a plant cell? Can it be found in an animal cell? |
To protect the cell from its surroundings as well as keeping everything inside the cell. Plant - YES Animal - YES |
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What is the function of a CELL WALL? Can it be found in a plant cell? Can it be found in an animal cell? |
Surrounds the cell membrane and provides cell with structural support and protection, it also acts as a filtering system. Plant - YES Animal - No |
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What is the function of CYTOPLASM? Can it be found in a plant cell? Can it be found in an animal cell? |
It is responsible for giving a cell its shape. It helps to fill out the cell and keeps organelles in place. Plant - YES |
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What is the function of CHLOROPLASTS? Can it be found in a plant cell? Can it be found in an animal cell? |
Absorb sunlight and use it in conjunction with water and carbon dioxide to produce food for the plant, capture light energy from the sun and produce the free energy through photosynthesis Plant - YES Animal - NO |
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What is the function of a VACUOLE? Can it be found in a plant cell? Can it be found in an animal cell? |
Contain the waste products of cells and isolate them from the rest of the organelles. Remove unwanted or toxic minerals from the cell. Plant - YES Animal - NO |
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What is the function of a MITOCHONDRIA? Can it be found in a plant cell? Can it be found in an animal cell? |
The 'powerhouse' of the cell. They are the working organelles that keep the cell full of energy. Plant - YES Animal - YES |
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What is the function of an ENDOPLASMIC RETICULUM? Can it be found in a plant cell? Can it be found in an animal cell? |
Transport and processing of proteins and lipids. May also transport substances from one cell to another in plant cells. Plant - YES Animal - YES |
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What is the function of RIBOSOMES? Can it be found in a plant cell? Can it be found in an animal cell? |
The 'machinery' that carries out the genetically coded instructions of DNA to produce proteins for cell function and structure. Plant - YES Animal - YES |
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What is the function of LYSOSOMES? Can it be found in a plant cell? Can it be found in an animal cell? |
Commonly break down worn out cell organelles so that materials can be used to make new ones. Plants - NO Animals - YES |
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What is the function of a GOLGI BODY? Can it be found in a plant cell? Can it be found in an animal cell? |
Process, package and sort cell products. Involved in adding proteins and carbohydrates to cell products, provide a cell membrane and determine their destination. Plants - YES Animals - YES |
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What are some examples of organic substances? |
- Carbohydrates - Lipids - Proteins - Nucleic acids |
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What are some examples of inorganic substances? |
- Water - Mineral salts - Gases (Carbon dioxide, Oxygen) |
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What is the current model of membrane structure? How does it account for the movement of substances in and out of cells? |
- Fluid Mosaic Model (moving, pattern) - Semi (selectively) permeable bilipid layer - Proteins can be interspersed throughout this structure. - Water is attracted by the hydrophilic end and repelled through by the hydrophobic middle layer. Water can also move through special protein channels. - Salt ions and larger carbs are actively transported (energy required) across the membrane though channel proteins. |
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What is diffusion? |
The movement of any type of molecule from a high to low concentration until equilibrium is reached. |
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What is osmosis? |
The movement of water molecules from a high to low concentration through a selectively permeable membrane. |
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Explain how the SA:V ratio affects the rate of movement of substances into and out of cells |
As any shape gets larger, its SA:V ratio gets smaller. In a large cell, there is relatively less SA for osmosis and greater volume for diffusion of substances to organelles. Organelles may also be further away from the membrane. The greater the surface area, the more effective the rate of diffusion. |
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Indicators to identify substances in tissues: Starch Glucose Protein Lignin Chloride Ions |
Iodine Benedicts Solution Biurets test (sodium hydroxide and copper sulfate) Toluidine blue Silver nitrate |
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What are Autotrophs? What are Heterotrophs? |
Autotrophs: organisms that produce their own food. Heterotrophs: Organisms that are not able to produce their own food, and are reliant on other organisms to survive. |
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What is the process of photosynthesis summarised as? |
water + carbon dioxide -> glucose + oxygen |
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What is photosynthesis? |
Photosynthesis occurs in the chloroplast of plant cells. The green pigment chlorophyll absorbs light energy from the process. This energy is then stored as chemical energy in the glucose molecules produced. |
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Glucose from photosynthesis can be converted into and stored as: |
- Lipids - Proteins - Complex carbohydrates |
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What is the relationship between the organisation of the structures used to obtain water and minerals in a range of plants and the need to increase the surface area available for absorption? |
Roots have an extensive surface area that allows water and inorganic mineral salts to be absorbed efficiently. Large amounts of water in plants is absorbed through osmosis. When the water in the soil is at a higher concentration than the root cells, water will move from the soil into the root. Increased SA in roots are achieved by root hair zone, extensive branching and epidermal cells. |
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What is the role of the external leaf structure? |
Arrangement: Leaves are arranged along stems in a way that exposes them to maximum sunlight. Shape: Broad, thin & flat shape of leaf provides large SA for capturing sunlight and gas exchange. |
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What is the role of the internal leaf structure? |
Cuticle: Waxy layer of leaf, is waterproof and provides protection. Does not burn. Epidermis: Protective layer of cells on upper and lower sides of leaves. Transparent to allow light to pass through Stomates: Pores in the leaf that open and close to allow gas exchange Veins: Tubes of vascular tissue that provide structure and shape. |
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What is the Xylem and Phloem? |
XYLEM: Transports water and minerals from roots to leaves. PHLOEM: Transports products of photosynthesis to the rest of plant. |
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What is the role of teeth in increasing the SA of complex foods to exposure to digestive chemicals? |
Chewing breaks food into smaller pieces with greater surface area, so it takes less time for digestive enzymes to attack it faster. Therefore the greater the surface area, the better the digestive chemicals can act on the food. |
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Digestion in Herbivores |
- Flat, grinding teeth to chew food thoroughly to increase the surface area exposed to enzymes. - Relatively long intestines and caecum, for more surface area and longer time available for digestion - Bacteria living in their gut which have enzymes to digest cellulose. |
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Digestion in Carnivores |
- Sharp, tearing teeth to cut flesh into chunks for swallowing.. chewing is not so important. - Relatively short intestines - A highly elastic stomach, which allows them to swallow a large meal. - The stomach acid and enzymes are vital for digesting their high protein meat diet. |
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Role of respiratory system? |
Enables organisms to take in oxygen and to remove carbon dioxide from their bodies.
E.G. LUNGS |
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Role of circulatory system? |
Main function is to transport gases, maintenance of a constant internal environment, removal of toxins and pathogens and distribution of heat. E.G. BLOOD, HEART, VEINS |
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Role of excretory system? |
Remove metabolic wastes from the transport medium. E.G. KIDNEYS |
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Role of digestive system? |
Absorbs nutrients and water |
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What is active transport? |
Energy must be used to cause the material to flow. |
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What is passive transport? |
Happens without any effort or energy from the organism. |
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What are XYLEM? |
Tubes that carry water and dissolved minerals from the roots to the leaves. "TRANSPIRATION" causes a suction effect at the top of each xylem tube, this draws more water from the roots. |
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What are PHLOEM? |
Transport sugars and other food nutrients using active transport of cytoplasm through each cell. The movement of food via the phloem is called "TRANSLOCATION". |
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What are LENTICLES? |
Simple structures on stems and trunks of plants which allow gas exchange to the cells by simple diffusion from the air. |
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What are ROOT HAIRS? |
Plants Absorb Water through specialoutgrowths on the roots called “root hairs”. Root hairs help absorption of water by greatlyincreasing the surface area of the root in contactwith the soil. Oxygen in soil diffuses into the root hair cells, and spreads toother root cells by further diffusion. |
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What are STOMATES? |
The lower leaf surface has many openings, called“stomates”. These receive the gases needed for photosynthesis by opening and closing to allow gas exchange. |
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What are radioisotopes? |
- Used to give information about the function of organs and tissue in living organisms. - They are atoms of elements with different numbers of neutrons from the original element, which are radioactive/ emit radiation. - They are able to be attached to molecules by chemical means and can then be traced to see how they are used and transported through the organs and tissues of the organism. - Scientists are able to develop 3D images of the information gathered |
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Radioisotopes in humans and animals? |
- Attach to red blood cells once injected into the body. - Travel through the circulatory system and are able to detect abnormalities in the functioning of the brain and blood vessels. - NEGATIVE: can cause health issues such as mutations in the DNA cells and can also cause cancers. |
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Radioisotopes in plants? |
- Used to track movement in and out of plants. - It was used to trace how sunlight is used in the chlorophyll to produce organic compounds AND to test whether the oxygen released in photosynthesis is that received from carbon dioxide or from water taken in during photosynthesis. - Track how quickly atoms are absorbed and where they are absorbed in plants which assists biologists in producing proper fertilising programs for commercial crops. |
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What is mitosis? |
- Where a single cell divides, resulting in two identical cells containing the same number of chromosomes and genetic content as that of the original cell.
- In a multicellular organism, this is vital for growth and repair. Cells cannot grow large, so the only way to grow larger is through many cells. Used to replace damaged and worn out cells in the body |
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Where are the sites of mitosis in plants? |
Only grow at certain places known as 'mermistems' located at: - The root tip - The 'buds' where shoots and flowers grow - In the cambium layer, between xylem and phloem (this is how the length of a stem/trunk gets larger) |
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Where are the sites of mitosis in insects? |
- Only occurs in special 'disks' of cells during a process of metamorphosis, in which their body tissues completely break down and are rebuilt to form the totally different adult. |
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Where are the sites of mitosis in mammals? |
- Mammals grow larger proportionally all over, therefore mitosis must occur in all parts of the body of a mammal. |
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What is the need for cytokinesis in cell division? |
Cytokinesis: the final division of mitosis When the cell membrane grows to divide cell into two parts. Cytokinesis gives and equal share of cytoplasm and organelles to each cell, ensuring the identical copy of each cell and avoiding mutation. |
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Which organelles inside a cell contain DNA? |
Nucleus contains the main store of genetic material. Mitochondria and chloroplasts are able to reproduce themselves in mini versions of cell division. |
