B1 - Cell Structure and Transport Flashcards
What is the magnification Triangle?
Image Size on Top (I)
Magnification on bottom (m)
Real object on bottom (R)
What is found in an Animal Cell?
Cell membrane, ribosomes, nucleus, mitochondria and cytoplasm.
What is found in most/all plant cells?
Cellulose cell wall, cell membrane, mitochondria, ribosomes, nucleus, cytoplasm, chloroplasts and a permanent vacuole filled with sap.
What is the function of the nucleus?
- Controls all the activities of the cell.
- Contains all the genetic information that is needed to build new cells or organisms.
- Average Diameter is around 10 nanometers.
What is the function of the cytoplasm?
- A liquid gel in which the organelles are suspended and where most of the chemical reactions needed for life take place.
What is the function of the cell membrane?
- Controls the passage of substances such as glucose and mineral ions into the cell.
- Controls the movement of substances such as urea or hormones out of the cell.
What is the function of mitochondria?
- Where aerobic respiration takes place in the cytoplasm.
- Release energy for the cell.
What is the function of ribosomes?
- Where protein synthesis takes place, making all the proteins needed in the cell.
What is the function of the cellulose cell wall?
- Strengthens the cell and gives it support.
What is the function of the chloroplasts?
- Found in the green parts of the plant.
- Chlorophyll give them the green colour.
- Absorbs light so the plant can make food by photosynthesis.
What is the function of the permanent vacuole?
- Space in the cytoplasm filled with cell sap.
- Important for keeping the cells rigid to support the plant.
What are the features of a eukaryotic cell?
- Cell membrane, cytoplasm and genetic material enclosed in a nucleus.
- Animals, plants, fungi and Protista are all eukaryotes.
What are the features of a prokaryotic cell?
- Cell membrane, cell wall, cytoplasm.
- Genetic material isn’t in a distinct nucleus - forming ga singular DNA loop.
- Prokaryotes may contain one or more small era rings of DNA called plasmids.
- Bacteria are prokaryotes.
What is the function of a nerve cell?
- Carry electrical impulses around the body of an animal.
- Provide a rapid communication system between the different parts of the body.
What is the function of a muscle cell?
- Specialist cells that can contract and relax.
- Striated muscle cells work together in tissues called muscles.
What is the function of a sperm cell?
- Released a long time from the egg they are going to fertilise.
- Contain the genetic material from the male parent.
What happens as an organism develops?
- Cells differentiate to form different types of cells.
What happens as an animal cell differentiates to form a specialised cell?
- It acquires different sub cellular structures to enable it to carry out a certain function.
What is the function of a root hair cell?
- Help plants to take in water and mineral ions more efficiently.
- Mostly relatively close to the xylem cells.
What is the function of a photosynthetic cell?
- Can help plants make their own food by using photosynthesis.
What is the function of a xylem cell?
- Transport plant that carries water and mineral ions from the roots to the highest leaves and shoots.
- Important in supporting the plant.
What is the function of a phloem cell?
- Carries the food made by photosynthesis around the body of the plant.
- Phloem cells don’t become lignified and die.
What are plant cells specialised for?
- To carry out a particular function.
What is diffusion?
- Diffusion is the spreading out of any substance, in solution or a gas, resulting in a net movement from an area of higher concentration to an area of lower concentration.
How is the rate of diffusion affected?
- Difference in concentrations, the temperature and the available surface area.
What is osmosis?
- The movement of water from a dilute to a more concentrated solute solution across a partially permeable membrane which allows water to pass through.
What is a dilute solution of sugar?
- Contains a high concentration of water and a low concentration of sugar.
What is a concentrated solution of sugar?
- Contains a low concentration of water and a high concentration of sugar.
What is meant by the term isotonic?
- Where the concentration of solutes in the solution outside the cell is the same as the internal concentration.
What is meant by the term hypertonic?
- Where the concentration of solutes in the solution outside of the cell is higher than the internal concentration.
What is meant by the term hypotonic?
- Where the concentration of solutes in the solution outside of the cell is lower than the internal concentration.
Why is osmosis important in plants?
- To maintain turgor in the plant cells.
What is active transport?
- Moves substances from a more dilute solution to a more concentrated solution against a concentration gradient.
How does active transport use energy?
- Energy released from food in respiration to provide the energy required.
How does active transport allow root hair cells in plants to work?
- Absorbs mineral ions required for healthy growth from very dilute solution in the soil against a concentration gradient.
How does active transport molecules allow sugar molecules to work?
- Used for cell respiration to be absorbed from lower concentrations in the gut into the blood where there is higher concentration of sugar is higher.
What are the features of a single celled organism?
- Relatively large surface area to volume ratio so all necessary changes with the environment take place over this surface.
What are the features of a multicellular organism?
- Many organs are specialised with effective exchange surfaces.
