B1- Cell Biology Flashcards
What is active transport?
The movement of molecules across a membrane from a region of lower concentration to a region of higher concentration. This requires energy from respiration.
What is a eukaryotic cell and what is an example of it?
Eukaryotic cells have a nucleus. They include all animal and plant cells.
What is a prokaryotic cell and an example of it?
Prokaryotic cells do not have a nucleus. An example of this would be a bacterial cell.
What is the purpose of mitosis and what happens during it?
Mitosis is aware of cell split into two identical daughter cells. The purpose of this is to allow growth from a pair of worn out cells, also it allows asexual reproduction to occur.
What features do plant cells have the animal cells don’t have?
Cell wall
Permanent vacuole
chloroplast.
What is the purpose of a cell wall?
Provides the cell with structural support and protection
What is the purpose of a permanent vacuole?
It contains cell sap, which is a weak solution of sugar and salts
What is the purpose of chloroplasts?
This is where photosynthesis occurs which makes food for the plant. They contain a green substance called chlorophyll which absorbs the light needed for photosynthesis.
What is the purpose of a nucleus?
It contains genetic material (DNA) that controls the activities of the cell.
What is the purpose of mitochondria?
This is where most of the reactions for aerobic respiration take place respiration transfers energy that the cell needs to work
What is the purpose of ribosomes?
This is where proteins are made in the cell
What is the purpose of the cell membrane?
This holds the cell together and controls what goes in and out of it
What is the purpose of cytoplasm?
It is a gel like substance where most of the chemical reactions happen. It contains enzymes that control these chemical reactions.
Name three examples of specialised cells
Sperm cells, nerve cells, muscle cells, root hair cells, phloem, and xylem cells
What is an example of an adult stem cell?
Skin, bone marrow
What are the groups of specialised cells called in plants?
Meristem cells
What is a stem cell?
An undifferentiated cell which is capable of becoming other cell types
What is the calculation for total magnification?
Total magnification = eyepiece lens X objective lens
What is diffusion?
The spread spreading out of particles from an area of high concentration to an area of lower concentration
What is osmosis?
The movement of water molecules across a partially permeable membrane from a region of higher water concentration to a region of lower water concentration
What are the advantages and disadvantages of light microscopes?
Advantages: cheap, portable, live
Disadvantages: low magnification, low resolution
What are the advantages and disadvantages of electron microscopes?
Advantages: much higher magnification, higher resolution, enable you to see smaller things in more detail than light microscopes
Disadvantages: very expensive, not portable, dead specimen
What do phloem cells do?
Transport glucose from the leaves to the rest of the plant
What is the definition of magnification?
How much bigger the image is than the actual specimen
What is the definition of resolution?
The ability to distinguish between two points
Function of plasmid
Carries genetic information
Function of flagellum
Helps the cell move
Adaptations of muscle cells
These cells long so they have space to contract and contain lots of mitochondria to generate the energy needed for the contraction
Adaptations of nerve cells
The cells are long and have branched connections at their end to connect to other nerve cells and form and network throughout the body
Adaptations of root hair cells
Long hair that sticking to the soil,
This gives the plant a big surface area for absorbing water and mineral irons from the soil
Adaptations phloem and xylem cells
Phloem and xylem cells form phloem and xylem tubes which transport substances such as food and water around the plants
To form the tubes, the cells are long and joined end to end
Xylem cell is hollow in the centre,
Phloem cells have very few subcellular structures so that stuff can flow through them
Adaptations of red blood cells
They are thin, so there is only a short distance for the oxygen diffuse to reach the centre of the cell. The shape provides a large circus area compared to the volume of the red blood cell allow allowing diffusion to happen efficiently
What factors affect diffusion?
- Temperature- higher the faster
- Concentration gradient- steeper the faster
- Surface area- bigger the faster
- Distance- shorter the faster
What factors affect diffusion?
- Temperature- higher the faster
- Concentration gradient- steeper the faster
- Surface area- bigger the faster
- Distance- shorter the faster
When does diffusion happen?
Plants: oxygen entering a leaf
Animals: getting oxygen into the blood
