Biology Flashcards
What 3 unique structures are found in a plant cell?
- Chloroplast
- Cell Wall
- Large Permanent Vacuole
Name examples of a eukaryotic cells.
- Animal cell
- Plant cell
What is a prokaryotic cell?
A cell that lacks a nucleus and other organelles. It has a DNA strand as opposed to nucleus.
What is a specialised cell? Give 3 examples.
A cell with unique characteristics which allows it to carry out a particular function.
- Red Blood Cell
- Sperm cells
- White Blood cells
- etc.
What is magnification in a microscope?
The ratio between image size and actual size
Name the two types of microscopes.
- Light microscope
- Electron microscope
What is the formula involving magnification, actual size, image size?
Image size = actual size * magnification (or a variation)
What process do cells undergo to be specialised?
Differentiation
What is the definition of a stem cell?
Stem cells are undifferentiated cells that can differentiate to form many different type of cells
Name the three types of stem cells.
- Embryonic stem cells
- Adult stem cells
- Plant (meristem) stem cells
Order organ, cell and tissue by size smallest to largest
Cell -> tissue -> organ
Which organelle are chromosomes found in?
Nucleus
How many chromosomes are found in the cell
23 pairs, 46 in total
What molecule makes up chromosomes?
DNA
What is the purpose of a gene?
A gene is a section of DNA that codes for the production of a protein (protein synthesis)
Mitosis is how cells divide. State 3 purposes of mitosis
- Growth
- Tissue repair
- Asexual reproduction
What is the cell cycle? Very briefly explain the stages.
Stage 1: Cell grows
Stage 2: Mitosis
Stage 3: Cytoplasm replicates and new cells created
What stage in its life can a plant cell differentiate?
At any point
What is diffusion?
Particles that move from an area of high concentration to an area of low concentration.
How can we increase the rate of diffusion? 3 answers required.
- Temperature
- Surface Area
- Concentration Gradient
What is osmosis?
Osmosis is the movement of only water particles from a dilute solution to a concentrated solution, across a partially permeable membrane.
What is meant by dilute?
Made of mostly water particles
What words can you use to replace “dilute” and “concentrated” in the osmosis definition?
Hypotonic and hypertonic (it is also good to know isotonic!)
What is active transport?
Active transport is when particles move against the concentration gradient (low to high). This requires energy.
What is resolution in microscopes?
The ability to see two objects as separate.
Why is DNA replication important in the cell cycle?
So that when the cell divides, each daughter cell contains the correct number of chromosomes.
What is replicated during the growth phase of the cell cycle?
Ribosome and Mitochondria
Genetically, how do daughter cells compare to parent cells?
Exact same genetic material
How to calculate percentage change?
% change = original-new/new x 100
Name 2 disadvantages and an advantage with light microscopes.
Compared to electron microscope:
- Lower resolution
- Lower magnification
- More portable
Why do we need stem cells in our body?
To constantly provide repair and growth for human cells regularly
