Studied by 6 peopleWhat organelles do both plants and animals have?
Nucleus, Cytoplasm, Cell Membrane
Give three differences between bacterial (prokaryotic) DNA and eukaryotic DNA
Bacteria don't have a nucleus. Bacterial DNA is single stranded. Bacterial DNA may be in the form of small loops called plasmids
How do you turn millimetres into micrometres?
x1000
Name 5 organelles found in an animal cell
Nucleus, Cell Membrane, Cytoplasm, Ribosome, Mitochondria
What happens in stage one of the cell cycle?
The cell grows and the number of organelles increases and DNA replicates
Name 2 organelles only found in plant cells
Chloroplasts and a vacuole
What is the difference between animal cell differentiation and plant cell differentiation?
Animal cells differentiate for a limited amount of time, whereas most plant cells can differentiate throughout the plants life
How have electron microscopes helped increase our understanding of sub-cellular structures?
They have a higher magnification and resolution than light microscopes so we can see smaller organelles, like ribosomes - which aren't visible under light microscopes
How can you calculate magnification
Magnification = eyepiece x objective lens
How is DNA stored in a cell?
As chromosomes in the nucleus
What happens in stage 2 of the cell cycle?
Mitosis - one set of chromosomes is pulled to each end of the dividing cell and the nucleus divides
What happens in stage 3 of the cell cycle?
The cells splits into two
What is mitosis used for?
Growth, Repair, Replacement and Asexual reproduction
What is a stem cell?
An undifferentiated cell
What is the role of stem cells in embryos?
At this point stem cells can differentiate into any cell type needed by the embryo
What is the role of stem cells in adults?
To replace body cells that die or are injured
What is the role of stem cells in the meristem?
The meristem is the only location that growth can happen in the plant. Meristem tissue can differentiate into many different types of cell throughout the plants life
Name two diseases that could be treated with stem cells
Diabetes and Paralysis
What is therapeutic cloning?
An embryo is made with the same genes as the patient. Stem cells from the embryo aren't rejected so they can be used for medical treatment
What is the role of the mitochondria?
Release energy by respiration
What is the role of the ribosome?
Make proteins
What is the role of the vacuole?
Stores cell sap
What is the role of the chloroplast?
Photosynthesis
How do you work out actual size of a magnified image?
Image size divided by magnification
Give a disadvantage of using embryonic stem cells
It destroys the embryo
Diffusion
The movement of molecules from an area of greater concentration to an area of lower concentration. Does not require energy. Example: Oxygen moves from the alveolar air space to blood around the lungs.
Osmosis
The movement of water across a semipermeable membrane through diffusion. Moving from an area of high concentration to low concentration.
Active transport
The movement of substances from an area of low concentration to an area of high concentration using a carrier protein. This movement is against the concentration gradient. As a result cells can absorb ions from very dilute solutions. It also enables cells to move substances, such as sugars or ions, from one place to another through the cell membrane.
Note
Flashcard