Cell structure Flashcards
Name the main features of plant and animal cells (eukaryotic cells)
Nucleus, cytoplasm, cell membrane, ribosomes, mitochondria + plants have vacuole, cell wall and chloroplasts
Recall the relative size of bacterial cells (prokaryotic cells)
0.1 micrometres to 5 micrometres
Describe the difference in how the genetic material is found within eukaryotic and prokaryotic cells.
In Eukaryotes: Genetic material stored in 23 pairs of chromosomes inside the nucleus. Each chromosome has lots of DNA strands which each control a certain biological characteristic.
In prokaryotes: Stored in circular strands of DNA that float around in cytoplasm
Complete magnification calculation equations using the formula
magnification = Image size/ actual size
A | M
Explain how the main sub-cellular structures, including the nucleus, cell membranes, mitochondria, cell wall and chloroplasts in plant cells and plasmids in bacterial cells are related to their functions
Nucleus: the control centre of the cell, tells the cell what to do. Contains cell DNA
cytoplasm: Gel-like substance where most chemical reactions occur.
cell membrane: Semi-permeable surface that controls what goes in and out of the cell. Maintains the cell structure
ribosomes: Produces cell proteins
mitochondria: Powerhouse of the cell. Respires using glucose from digestion/ photosynthesis, water and oxygen to release energy to the cell.
chloroplasts: has chlorophyll to absorb sunlight, and then photosynthesize using carbon dioxide and water to produce oxygen and glucose
plasmids: small separated fragments of DNA found in bacterial cells
Explain how the structure of different types of cell relate to their function in a tissue, an organ or organ system, or the whole organism. Including sperm cells, nerve cells and muscle cells in animals and root hair cells, xylem and phloem cells in plants.
sperm cells: long and streamline to help it glide. Strong flagellum to help it propel itself. Enzymes in the head to help it digest its way into the ovum. lots of mitochondria to provide lots of energy. job is to fertilize the female egg for reproduction
nerve cells: long with lots of branches to transport messages quickly over long distances and to create a network across the body with other nerve cells.
muscle cells: lots of mitochondria to provide lots of energy for contractions. Long so that they have space to contract.
root hair cells: lots of hair like projections on the surface of plants to maximize absorption of water and mineral ions. Big surface area to volume ratio
xylem: specialized to allow fast transportation of things inside plants. long and hollow
phloem cells:
specialized to allow fast transportation of things inside plants. very few sub cellular structures to maximize efficiency
Describe cell differentiation
Things become specialized with unique features so that they can better perform their individual task. For example, villi in the small intestine has a large surface area to maximize the rate of diffusion
Describe the differences in magnification and resolution between electron and light microscopes
Light/ optical microscope: cheaper, lighter, simpler, smaller, less magnification, colour image, less resolution
Electron microscope: more expensive, bigger, heavier, harder to use, monochrome image, 3d image with depth, higher magnification, higher resolution
Define binary fission
The process of prokaryotic cells dividing for cell duplication. Circular strand of DNA duplicates and moves to opposite poles of the cell. Cell wall, cytoplasm and plasmids also replicate, and begin to divide. The two daughter cells are almost identical except for the number of plasmids,
Explain how to prepare an uncontaminated culture
Several methods that are important to a fair test:
- Sterilizing the petri dish as well as any equipment used (measuring devices, spatula etc). Can be done using ethanol and burning
- Minimizing the exposure of air contact with the agar plate so that no additional microbes are inoculated onto the culture.
- Work below a bunsen burner flame to avoid more contamination from microbes.
- Taping the plate lightly shut to prevent microbes from entering once completed.
