Cell Cycle, Chromosones, Mitosis Flashcards
Where are chromosomes found in eukaryotic cells?
Nucleus
What is a gene?
Section of DNA that controls a particular feature eg eye colour
Whats stage 1 of cell cycle?
Initial growth and DNA replication
What is stage 2 of the cell cycle?
Mitosis
What is stage 3 of the cell cycle?
Cell division
EXPLAIN what happens in stage 1 of cell cycle
the cell grows and a copy of each chromosome is made
EXPLAIN what happens in stage 2 of cell cycle
The nucleus divides and one set of the chromosomes are pulled to each end of the dividing cell.
EXPLAIN what happens in stage 3 of cell cycle
The cytoplasm and cell membrane divide to form 2 identical daughter cells.
What is differentiation?
The cells of a multicellular organism divide, grow and develop, they differentiate into specialised cells.
What is a stem cell?
An undifferentiated cell (no function) that can differentiate into any type of specialised cell.
Where can stem cells be found in animals?
Embryos (embryonic stem cells) and in adult bone marrow
Where can stem cells be found in plants?
Meristems ( roots and shoots )
When does differentiation occur in animals?
is differentiation permanent?
when does animal stop growing?
When ur in embryo
Yes, cant be undone
Little or no growth after animal is an adult
When does differentiation occur in plants?
is differentiation permanent?
when does plant stop growing?
Meristems
No, u can take a plant cell from a leaf and make a new plant
Continuous, throughout life
Why can plants easily be cloned?
Because differentiation is not permanent in plants.
Whats the 4 step process for cloning plants?
Remove part of plant
Add it to a agar plate (contains required minerals)
The cells can re differentiate back into stem cells (callus)
Stems will then then differentiate into specialised cells
3 reasons why we should clone plants?
Save endangered species from extinction
Quick and cheap so plants can be sold
Plants can be produced in large numbers and used for research.
When a sperm cell fertilises an egg cell, what does it form?
Zygote
3 problems or diseases that using stem cells can solve.
Diabetes, dementia, infertility ALSO used for organ transplants
5 problems of the use of stem cells
Aborted embryos are used ( ethical and religious problem )
Autoimmune system may reject cells
Rapidly dividing cells can cause cancer.
Risk of viral infections
Slow progress and expensive
What other places can embryonic stem cells be found except embryos
Umbilical cord and amnionic fluid
Why is therapeutic cloning used?, and why does it work( to prevent…)
To prevent autoimmune response
It works because you are not using anyone elses cells, but using cells with your own DNA
What is the 3 step process of therapeutic cloning?
- Nucleus is removed from adult cells
- nucleus is inserted inti enucleated egg cell ( no nucleus )
- Egg cell stimulated with electricity to cause the egg cell to divide into an embryo so lots of stem cells are available.
