Biology topic 1 Flashcards
What is the role of the cell membrane?
Filter what enters and exits the cell
What is the role of the cell wall?
Provides structure
What is the role of ribosomes ?
Where proteins are made
What is the role of mitochondria
Power house of the cell- energy
What is the role of chloroplasts
Where photosynthesis takes place
What is the role of the nucleus?
Where DNA is held
What is the main difference between prokaryotic and eukaryotic cells?
- Eukaryotic cells have a nucleus, prokaryotic cells have a loop of DNA
- prokaryotic cells and much smaller
Where is DNA held in bacteria cells?
- loop of DNA
- Small rings called plasmids
What do plant cells have that animals cells don’t
- permanent vacuole
- cell wall
- chloroplasts
What do both animal and plants cells have?
- mitochondria
- ribosomes
- nucleus
-cytoplasm
What are the special features of a root hair cell? And why are they helpful?
- long projection
- large surface area allows more more absorption of nutrients
What are the special features of a sperm cell? And why are they helpful?
- the tail is helpful for propelling
- the head is streamlined
- lots if mitochondria to supply energy
What are the special features of a nerve cell? And why are they helpful?
- very long to allow impulses to be transported over long distances
- lots of connections to allow impulses to be transported to lots of different areas of the body
Why is an electron microscope considered better than a light microscope?
- higher magnification
- better resolution
What are the stages of the cell cycle?
- DNA duplicates and the cell grows in size
- one set of chromosomes is pulled to each end of the cell
- Cell member and cytoplasm divides
What is a stem cell?
- an undifferentiated cells
- it has no specific characteristics that make it able to perform a function
Where can stem cells be found?
-Found in embryos all in bone marrow
Why are stem cells useful?
- they can cure diseases where you have insufficient cells or faulty cells
- e.g diabetes- lack the cell to produce insulin
What issues might arise from stem cell research?
- ethical issues
- limited knowledge
- risk contamination which leads to infections
What is diffusion?
- spreading of particles from a high concentration to a low concentration
What factors affect the rate of diffusion?
- the difference in concentration
- temperature
What is osmosis?
- diffusion of what we from a dilute solution to a high concentration of
What is active transport?
- movement of particles from a low concentration to a high concentration
- requires energy
