Cell Biology Flashcards
What is the name of when cells specialise?
Differentiation.
What does undifferentiated mean?
Cells that can form other types of cells.
Where can stem cells be found in the human body?
Bone marrow.
What type of cells can stem cells in the bone marrow differentiate into?
Blood cells.
Define Osmosis
The movement of water from a dilute to a more concentrated solution through a partially permeable membrane
Define active transport
Substances move from a low to a high concentration (against the concentration gradient) which requires energy from respiration
How is active transport used in plants
Mineral ions can be absorbed into the plant root hairs from very dilute solutions in the soil
How is active transport used for movement of sugar molecules
Active transport allows sugar molecules to be absorbed from lower concentrations in the gut into the blood which has a higher sugar concentration
What do animal and plant cells contain
Plant and animal cells (eukaryotic cells) have a cell membrane,
cytoplasm and genetic material enclosed in a nucleus.
Features of bacterial cells
Bacterial cells (prokaryotic cells) are much smaller in comparison. They have cytoplasm and a cell membrane surrounded by a cell wall. The genetic material is not enclosed in a nucleus. It is a single DNA loop and there may be one or more small rings of DNA called plasmids
Function of mitochondria
Site of aerobic respiration
Function of ribosomes
Site where protein synthesis occurs
Function of nucleus
Contains genetic material, including DNA, which controls the cell’s activities.
Function of cytoplasm
here many of the chemical reactions happen.
Function of cell membrane
controls the movement of substances in and out of the cell.
do electron or light microscopes have a higher magnifying power
Electron microscope
What is the name of cell division for bacteria
Binary fission
How long does it take for bacteria to divide with sufficient nutrients and a suitable temperature
every 20 minutes
What is the cell cycle
the process of Cells dividing in a series of stages
Stage 1 of cell cycle
Before a cell can divide it needs to grow and increase the number of sub-cellular structures such as ribosomes and mitochondria. The DNA replicates to form two copies of each chromosome.
Stage 2 of cell cycle
In mitosis one set of chromosomes is pulled to each end of the cell and the nucleus divides.
Stage 3 of the cell cycle
Finally the cytoplasm and cell membranes divide to form two identical cells.
Why is cell division by mitosis important
Cell division by mitosis is important in the growth and development of multicellular organisms.
What is a stem cell
A stem cell is an undifferentiated cell of an organism which is capable of giving rise to many more cells of the same type, and from which certain other cells can arise from differentiation.
How can stem cells from human embryos be used
Stem cells from human embryos can be cloned and made to
differentiate into most different types of human cells.
What can stem cells from adult bone marrow form
Stem cells from adult bone marrow can form many types of cells
including blood cells.
What can meristem tissue differentiate into
Meristem tissue in plants can differentiate into any type of plant cell, throughout the life of the plant.
What can stem cells treat
Treatment with stem cells may be able to help with conditions such as diabetes and paralysis.
What occurs in therapeutic cloning
In therapeutic cloning an embryo is produced with the same genes as the patient. Stem cells from the embryo are not rejected by the patient’s body so they may be used for medical treatment.
What are the risks of using stem cells
The use of stem cells has potential risks such as transfer of viral
infection, and some people have ethical or religious objections.
