B2 - Cell Division Flashcards
(25 cards)
Nucleus
Where the genetic material is found in cells
Chromosomes
- structure made of DNA molecules (polymer)
- containing many genes
Genes
A section of DNA that code for a protien. It can determine characteristics
DNA
The chemical that chromosomes are made of
Cell cycle
The three stage process of cell division that results in the formation of two identical daughter cells
What is cell division needed for
- Growth
- Repair
- Asexual Reproduction
- Replacement of cells
- development of multicellular organisms
Stage 1 of cell cycle
-The cell grows
- Number of sub cellular structures increases (mitochondria and ribosomes)
- DNA duplicates ~ two copies of each chromosome
Stage 2
Called Mitosis
- The chromosomes become thicker
- They line up in the middle of the cell
- One set of chromosomes is pulled to each end of the cell
- nuclei divides
Stage 3
Called Cytokinesis
- The cytoplasm and cell membrane divides
- Two new genetically identical daughter cells are formed
Differentiate
The process where cell become specialised for a particular function
Stem cells
Undifferentiated cell that can produce specialised cells or more stem cells
Embryonic Stem Cells
- early embryo
- can be cloned
- can differentiate in to all human cells cells
Adult Stem Cells
- can differentiate into limited number cells ~ including blood cells
- found in bone marrow
Meristem cells
Plant cells that can differentiate into all cells throughout the plants life
Cloning
The production of identical off spring through a sexual reproduction
Therapeutic cloning
- same genes as patient
- not rejected by patient
Animal Differentiation
Early stage
Plant Differentiation
Throught life
Ad and Dis of Embryonic Stem cells
Advantages
- Differentiate into all cells
- treat many diseases
- can be made in labs
Disadvantage
- Embryo harmed
- may not work
- consent cannot be asked
- religion
Dis and Ad of Adult stem cells
Advantages
- consent can be given
- safe
- tried procedure
Disadvantages
- Cannot differentiate into all cells
- treat less diseases
- infection
- removal can be painful
Risks of both adult and embryonic
Viral infection and can be cancerous
how many chromosomes are there in a body
- 46
-23 pairs
which conditions can stem cells help?
- paralysis
- diabetes 1
therapeutic cloning con
- Transferal of viral infection
- ethics or religious objections
