Topic B1-Microscopes, Cells, Transport, Cell Division & Stem Cells Flashcards
How many micrometers are there in 1 metre?
1, 000, 000
What kind of microscope do we use at school?
Light microscope
What kind of microscope allowed biologists to see and understand more about subcellular structures inside?
Electron microscope
How can you calculate real size of a microscope image?
Image size
___________
Magnification
What determines how much detail a microscope can show?
Resolving power
What kind of cell contains genetic material enclosed in a nucleus?
Eukaryotic
What kind of cell does not have a nucleus
Prokaryotic / bacterial cell
Which is smaller?: eukaryotic or prokaryotic cells
Prokaryotic
What is the function of the nucleus
Hold DNA
Function of cytoplasm?
Chemical reactions
Function of cell membrane?
Controls what enters and exits cell
Function of mitochondria
Site of aerobic respiration
Function of ribosomes?
Sure of protein synthesis
Function of choloroplasts
Site of photosynthesis
Function of chlorophyll
Absorbs sunlight for photosynthesis
What is vacuole filled with
Cell sap
What are plant and agal cell walls made of?
Cellulose
Which specialised cells contain lots of mitochondria?
Sperm cells,
Muscle cells
Root hair cells
Which specialises cell has a long axon?
Nerve cell/ neurone
Which specialised cells contain protein that slide over each other and store glycogen?
Muscle cells
Which specialised cells have a large surface are, permanent vacuole and lots of mitochondria for active transport?
Root Hair Cell
Which specialised cells have broken down cell walls that form sieve plates and are supported by companion cells?
Phloem cells
Which specialised cells become lignified and die?
Xylem cells
With a suitable temperature and nutrients, how often can some bacteria divide?
Every 20 minutes
Where are chromosomes found?
Nucleus
What are the 3 stages of the cell cycle?
• Genetic material is doubled then divided into 2 identical cells
• Growth and reproduction of sub-cellular structures
• Mitosis (chromosomes pulled to each end of the cell and nucleus divides)
what is an undifferentiated cell of an organism that can give rise to many more cells of the same type and from which certain cells can arise from (differentiation) ?
stem cells
Which tissue can develop into any type of plant cell throughout its life?
Meristem
What may stem cells be used to help treat?
Diabetes, paralysis
Disadvantages of stem cells…?
• Potential risks
- such as viral transfer
• Ethical or religious objection
What is diffusion?
The spreading out of particles from a high concentration to a low concentration
What 3 factors affect the rate of diffusion?
1) concentration gradient
2) temperature
3) surface area
What is the effectiveness of an exchange surface increased by?
• Large surface area
• Thin efficient blood supply
• Being ventilated to maintain the concentration gradient
What is osmosis?
Diffusion of water from a dilute to a more concentrated solution through a partially permeable membrane
What does active transport require?
Energy
describe the structure of cytoplasm
fluid compenent, contains organelles, enzymes and dissolved ions and nutrients.
describe how nerve cells in animals are adapted for their function
long axon - electrical impulses to be transmitted all over body
dendrites - to recieve impulses from other cells
myelin sheath - insulates the axon and speeds up the transition of impulses along the nerve cell
