B1 Flashcards
Name 5 parts that an animal and plant cell have in common.
Nucleus, cytoplasm, cell membrane, mitochondria, ribosomes
Name 3 features of a plant cell that are not in an animal cell.
Chloroplasts, permanent vacuole (filled with cell sap), cell wall
Describe the function of the nucleus.
Contains the genetic material of the cell
Describe the function of the cytoplasm.
The location of cellular reactions
Describe the function of the cell membrane.
To determine what is allowed in and out of the cell
Describe the function of the mitochondria.
Where aerobic respiration occurs to release energy
Describe the function of the ribosomes.
To bond amino acids together to form proteins (protein synthesis)
Describe the function of the chloroplast.
The location of photosynthesis
Describe the function of the permanent vacuole.
A storage area for ions and water sometimes pigments
What is the definition of a cell?
The individual unit of an organism
What is the definition of a tissue?
Cells of the same type working together to perform a specific function
What is the definition of an organ?
A structure made from multiple tissue types to perform a specific function
What is the definition of an organ system?
Multiple organs working together to perform a specific function
What is cell differentiation?
The process of a stem cell dividing and becoming a specialised cell
What are the two advantages of electron microscopes over light microscopes?
- Increased magnification
- Increased resolution
What is the resolution or resolving power of a microscope?
The ability to determine two close objects as separate images
How much smaller is a micrometre than a millimetre?
1,000
By what process do bacterial cells divide?
Binary fission
What is a chromosome?
A coiled thread like structure of nucleic acids (DNA) and protein found in the nucleus of eukaryotic cells
What is mitosis critical for?
Growth, repair and development of an organism
What is a stem cell?
An undifferentiated cell
What is a potential use of stem cells in medicine?
To treat conditions where cells have been damaged e.g. diabetes, paralysis
What is the principal of therapeutic cloning?
An embryo is produced with the same genes as the patient
Give an advantage of therapeutic cloning.
No rejection of the new cells by the patient (as they are the patient’s own cells)
Give two potential problems with therapeutic cloning.
- Risk of viral infection
- Religious/ethical objections around the use of embryos
Define diffusion.
The net movement of particles from an area of high concentration to an area of low concentration down a concentration gradient
Name three factors which affect the rate of diffusion.
- The difference in concentrations (concentration gradient)
- Temperature
- Surface area of the membrane
Name two common features that aid the exchange of substances in animal small intestine and lungs, fish gills, plant roots and leaves.
- Large surface area
- Thin membrane to provide a short diffusion path
Name two further features that aid the exchange of substances in animals but not plants.
- An efficient blood supply
- The ability to ventilate (to allow air to move in and out of the organism)
Define osmosis.
The diffusion of water from a high water potential to a low water potential through a partially permeable membrane
Define active transport.
The movement of substances from a low concentration to a high concentration (against a concentration gradient)
From what reaction does the energy required for active transport come?
Respiration
Give two examples of where active transport is used in Biology (one plant, one animal).
- Plant root hair cells absorbing mineral ions from the soil
- Glucose absorption from the small intestine into the blood
By what process do bacterial cells provide?
Binary fission
If provided with enough nutrients and a suitable temperature, how often can bacterial cells divide?
Around every 20 minutes
Describe the two ways bacteria can be grown in the laboratory.
- In a nutrient broth solution
- On an agar gel plate/petri dish
What is a contaminant?
An unwanted species of microorganism growing in your culture
What should you do with petri dishes and culture media before use?
Sterilise it a high temperature to kill contaminants
How do you sterilise inoculating loops?
Pass them through a bunsen burner flame before use
How should a petri dish be stored in school?
Upside down with tape securing the lid
What is the maximum temperature cultures should be incubated at in schools/colleges?
25 degrees Celsius
Explain why the maximum incubation temperature for bacterial cultures in schools is 25 degrees celsius?
To avoid growing potential pathogens
If you were asked to calculate the cross sectional area of a circular clear area around a disinfectant, what equation would you use?
Pi R squared
