1 Cell Biology - Cell Division Flashcards
What is a gene?
A short section of DNA that codes for a protein/controls a characteristic
What are chromosomes?
Structures in the nucleus that carry genes
How many chromosomes are in one human body cell?
46
Chromosomes are arranged in ___ pairs in a human body cell.
23
How many percent of your chromosomes have you inherited from your father?
50%
Briefly describe the cell cycle.
Cell content (including DNA) is replicated, mitosis occurs to make two genetically identical cells
Define ‘mitosis’.
Cell division that produces two genetically identical daughter cells
Which type of reproduction is based only on mitosis?
Asexual
State three key importances of mitosis.
Growth, repair, asexual reproduction
Briefly describe the first stage in the cell cycle.
Cell size increase, DNA and organelle replication
Briefly describe the second stage (mitosis) in the cell cycle.
Nucleus divides - One set of chromosomes is pulled to each end of the dividing cell
Briefly describe the third stage in the cell cycle.
Cytoplasm and cell membrane divides into two daughter cells
What has to happen to the cell before mitosis to ensure we can two genetically identical daughter cells?
DNA and organelles must replicate before division
Define ‘differentiation’.
The process where a cell becomes specialised/adapted to perform specific functions
Define ‘stem cell’.
Undifferentiated cell with the potential to become specialised
Define ‘adult stem cells’.
Stem cells that can only differentiate into a specific type of cell
Where does differentiation of stem cells occur in humans?
Bone marrow
Where does differentiation occur in plants?
Meristem/Root tip/Shoot tip
Define ‘cloning’.
Production of identical offspring by asexual reproduction/mitosis
By which cell division type does cloning occur?
Mitosis
Define ‘zygote’.
The single new cell formed right after fusion of gametes(sperm and egg)
Define ‘embryo’.
A ball of cells made from mitosis of zygote
Define ‘embryonic stem cells’.
Stem cells from an early embryo that can differentiate into all cell types
Where do you get adult stem cells in animals?
Brain, bone marrow, blood vessels, skeletal muscle, skin, teeth, heart, gut, liver
Suggest two diseases that may be treated with stem cell treatment.
Paralysis, diabetes, blindness
Briefly describe how we can use stem cells to treat someone with type 1 diabetes.
Induce embryonic stem cells to produce healthy pancreas cells to make enough insulin
Where do you get stem cells in plants?
Meristem/Root tip/Shoot tip
Why is the ability to clone plants quickly a benefit?
Produce large numbers of rare plants reliably and safely to stop their extinction and for research, agriculture advances
State one medical/scientific benefit of therapeutic cloning.
No rejection problem
State one risk or concern people may have about using stem cells.
Concerns: Unethical to use aborted embryos; difficult and expensive project; cancer concern; Risk: viral infection/transmission
