Sherpa

Existing user?

Combined Science: Biology

GCSE · Edexcel · higher

QuestionsFlashcards

Disease
Defence Against Disease
Development of Medicines
- Antibiotics
  4
- Discovery & Development of New Drugs
  6
Non-Communicable Diseases
- Lifestyle & Non-Communicable Disease
  8
- Cardiovascular Disease
  6

The Organism in the Environment
Human Influences on the Environment
- Human Impact on Biodiversity
  6
- Benefits of Maintaining Biodiversity
  6
Cycles within Ecosystems

Prokaryotic Organisms Flashcards

All 7 cards in this deck

What is the characteristic feature of a prokaryotic cell?: It has no nucleus — its chromosomal DNA lies free in the cytoplasm.
What is plasmid DNA?: A small circular loop of DNA in a bacterial cell, separate from the chromosomal DNA.
What is the function of a bacterial flagellum?: It moves the cell (motility); a bacterium without flagella, e.g. Streptococcus, is not motile.
True or false? Bacterial cells do not have ribosomes.: False. Bacteria do have ribosomes; what they lack is membrane-bound organelles such as mitochondria and chloroplasts.
Why are the cells of organisms such as birds described as eukaryotic?: They have membrane-bound organelles, including a nucleus.
True or false? The cell wall of a bacterial cell is made of cellulose.: False. Bacteria do have a cell wall, but it is not made of cellulose — cellulose cell walls are found in plant cells.
What kind of genes can plasmids carry, and how can they spread?: Extra genes, such as genes for antibiotic resistance; plasmids can be passed from one bacterium to another.