B1 & B2.1 - Cells & Cell Division Flashcards
What are the main characteristics of an Animal Cell?
Nucleus, Cytoplasm, inelastic, partially-partially-permable Cell Membrane, Mitochondria, Ribosomes
Cytoplasm
Liquid gel where organelles are suspended. This is where most of the chemical reactions needed for life take place.
Nucleus
Controls all the activities of the cell that contains genetic material, which carry instructions for making proteins needed to build new cells / organisms.
What are the main characteristics of a Plant Cell?
Components of an Animal Cell + Chloroplasts, Permanent Vacuole and Cellulose Cell Wall.
Cell Membrane
Controls passage of substances into the cell (glucose and mineral ions), as well as movement out of the cell (urea and hormones).
Mitochondria
Where aerobic respiration takes place, releasing energy for the cell.
Ribosomes
Where protein synthesis takes place, making all the proteins needed in the cell.
True or False?
Plant Cells do not contain all the characteristics of an animal cell (cell membrane, cytoplasm etc.)
False!
Plant Cells have all the features of a typical animal cell, but they also contain features that are needed for their very different functions.
True or False?
All plant and algal cells have a cell wall made of cellulose that strengthens the cell and gives it support.
True.
Chloroplasts
Contains chlorophyll, which makes chloroplasts green! Chlorophyll absorbs light for photosynthesis.
Permanent Vacuole
A space in the cytoplasm filled with cell sap. Important for keeping the cells rigid to support the plant.
True or False?
A plant cell has many features in common with an animal cell, as well as other features that are unique to plants.
True!
Plant Cells have added features, such as chloroplasts and a permanent vacuole.
True or False?
Roots cell contain chloroplasts because they are underground and need to photosynthesise.
False!
Because they are underground, they cannot absorb sunlight; a key component in producing their own food through photosynthesis. As a result, they do not have chloroplasts!
Define Prokaryotic
Pro- = Before / None
- kary- = Karyon = Nucleus
- Otic = State / condition
= A cell in which their genetic material is encased WITHOUT a nucleus, thus freely moving around in the cell.
Define Eukaryotic.
Eu - “Eureka” = True / Aha!
- kary- = Karyon = Nucleus
- Otic = state / condition of an entity
= A cell which has their genetic material encased WITH a nucleus.
Give an example of a Prokaryotic Cell.
Bacteria
Give an example of a Eukaryotic Cell.
Animal and plant cells!
What is a Eukaryotic cell?
Cells which all have a cell membrane, cytoplasm, and genetic material that is enclosed in a nucleus.
What is a Prokaryotic cell?
Much like eukaryotic cells, except their genetic material that is NOT enclosed in a nucleus, and may also contain extra small rings of DNA called plasmids.
What are plasmids?
Located usually in Prokaryotic cells (e.g. Bacteria), DNA which are codedfor very specific features such as antibiotic resistance.
What is a flagellum?
A long protein strand that lashes about to allow the cell to move around.
What effect does bacteria have on other organisms.
Little to no effect. Many are very useful.
Diffusion
Net movement of particles from an area of high concentration to an area of low concentration.
Effect of Diffusion
Usually results in equilibrium; same number of particles on each side.
Net Movement
Net movement = particles moving in - particles moving out
Why Diffusion is Passive
Doesnt need energy: particles move down the concentration gradient easily.
Factors affecting Diffusion
• Temperature:
higher temperature = more kinetic energy for particles to richochet/bounce off each other.
- Particles move around quicker consequently.
• Steeper Concentration Gradient:
Steeper gradient = greater net movement of particles.
Active Transport
Moving UP / against a concentration gradient, which needs energy.
Examples of Active Transport
• Nerve Cells:
Active transport of Sodium moving out and Potassium moving in the nerve cell.
• Root Hair Cells:
Magnesium ions actively transported into the root hair cell.
Difference between Active Transport & Diffusion
- ATP (adenosine triphosphate) is needed for Active Transport.
- Active Transport is going against the concentration gradient; lower concentrated particles moving to an area of higher concentration.
- Diffusion doesn’t need energy.
- Diffusion goes down the concentration gradient; higher concentrated particles moving to an area of lower concentration.