Biology- cells Flashcards
Adaptations of a root hair cell
Hairs to increase surface area (increase water absorption), no chloroplasts
Definition of mitosis
When cells divide to make 2 identical cells (happens in every living cell)
Definition of meiosis
Type of cell division that produces gametes (egg + sperm cells). Happens in reproductive organs
Definition of active transport
Movement of substances AGAINST the concentration gradient (low to high) so it needs ENERGY
Definition of osmosis
The movement of water molecules across a partially permeable membrane from an area of high water concentration to an area of low water concentration
Definition of diffusion
The movement of particles from an area of high concentration to an area of low concentration
What is the practical to show osmosis
Potato chip in difference sugar solutions to find the change in mass
What is binary fission?
Where the prokaryotic cell splits into two to reproduce.
What is the 4 step process of binary fission
- Circular DNA and plasmid(s) replicate
- Cell gets bigger and the circular DNA strands move to opposite ‘poles’ (ends) of the cell
- Cytoplasm begins to divide and new cell walls begin to form
- Cytoplasm divides + 2 daughter cells are produced. Each has 1 copy of circular DNA but have a variable number of copies of the plasmid(s)
What is the formula for magnification
Magnification= image size/ actual size
(Can use the formula triangle to rearrange)
Why do cells differentiate?
To become specialised
What are the examples of specialised cells?
- Sperm cells for reproduction
- Nerve cells for rapid signalling
- Muscle cells for contraction
- Root hair cells for absorbing water + minerals
- Phloem + Xylem for transporting substances
Why does our body need to make new cells
Growth, development and repair
