Cell Biology (AQA Spec) Flashcards
What type of cell are plant and animal cell?
Eukaryotic
What do eukaryotic cells have?
• Cell Membrane
• Cytoplasm
• Genetic Material enclosed in a nucleus
What type of cell is a bacteria cell?
Prokaryotic
Which type of cell is larger? Prokaryotic or Eukaryotic?
Eukaryotic
What do prokaryotic cells have?
• Cytoplasm
• Cell Membrane
• Cell Wall (surrounds cell membrane)
• Genetic material (NOT enclosed in nucleus)
How is genetic material found in prokaryotic cell?
Single DNA loop
What is it called when there is 1 or more small rings of DNA?
Plasmids
What do most animal cells have?
• Nucleus
• Cytoplasm
• Cell membrane
• Mitochondria
• Ribosomes
In addition to the parts found in animal cells, plant cells often have:
• Chloroplasts
• Permanent Vacuole (filled with sap)
What additional part do Plant and Algal cells have?
Cell Wall - made of cellulose which strengthens the cell
Describe how to prepare an uncontaminated culture using aseptic technique.
- Petri dishes and culture media must be sterilised before use
- inoculating loops used to transfer microorganisms to the media must be sterilised by passing them through a flame
- the lid of the Petri dish should be secured with adhesive tape and stored upside down
- in school and college laboratories, cultures should be incubated at a maximum temperature of 25°C.
What does the nucleus of a cell contain?
Chromosomes made up of DNA molecules
What does each chromosome carry?
A large number of genes
In body cells, how are the chromosomes usually found?
In pairs
Describe what happens during the cell cycle
During the cell cycle the genetic material is doubled and then divided into two identical cells.
Before a cell can divide it needs to grow and increase the number of sub-cellular structures such as ribosomes and mitochondria. The DNA replicates to form two copies of each chromosome.
In mitosis one set of chromosomes is pulled to each end of the cell and the nucleus divides.
Finally the cytoplasm and cell membranes divide to form two identical cells.
What is a stem cell?
A stem cell is an undifferentiated cell of an organism which is capable of giving rise to many more cells of the same type
What can stem cells from human embryos be used for?
Stem cells from human embryos can be cloned and made to differentiate into most different types of human cells.
What can stem cells from adult bone marrow be used for?
Stem cells from adult bone marrow can form many types of cells including blood cells.
What can meristem tissue be used for in plants?
Meristem tissue in plants can differentiate into any type of plant cell, throughout the life of the plant.
What are some risks/issues with using stem cells?
The use of stem cells has potential risks such as transfer of viral infection, and some people have ethical or religious objections.
