Chapter 7 Flashcards
Digestive cells
Shot life span because of their harsh environment.
Red blood cells
Can’t survive without nucleus, can’t replicate. Comes from bone marrow through blood vessels.
Nerve cells
Can’t reproduce, highly specialised.
Histones
Proteins that DNA raps around.
G1
Growth of cytoplasm and organelles.
S
Replication of DNA (chromosomes)
G2
Growth in cell size, preparation for mitosis.
Prophase
Chromosomes become visible. Spindle fibres start to form.
Metaphase
Chromosomes line UN along the equator facing each pole.
Anaphase
Chromatids separate and become chromosomes. The spindle fibres contract.
Telophase
The nucleus forms and the chromosomes start to unwind.
Cytokinesis
In plant cells and animal cells it’s when the membranes separate them.
DNA
Deoxyribonucleic acid
Spindle fibres
Microtubules
Kinetochores
The stuff that the spindle fibres attach to and surround the centreme.
Cell plate
Cytokinesis in plants. Barrier in between the two new cells.
Cleavage
Cell membrane in animals cells for cytokinesis. When they form up its cleavage furrow.
Binary fission
Replication of organelles.
Prokaryotes: Replicates single strand of DNA and then separates.
Apoptosis
Suicide of a cell
Eg, tadpole tail.
Caspases
Enzyme that activates apoptosis
Blebs
Membrane brake down, growths off the plasma membrane.
When does apoptosis occur?
When it’s old or infected
When apoptosis goes gong what happens?
Cancer forms. Can form from mutated genes.
Necrosis
Cell death from external factors.
Macrophage………… phagocytes
White blood cells. Use enzymes and lysosomes to brake down debris.
Proto-oncogenes
They code cell dividing Proteins. Regulate apoptosis, if uncontrolled courses cancer.
Mutagen
An agent that increase the frequency of mutation in DNA.
Carcinogen
A cancer coursing agent.
Teratogen
An agent that courses physics lesson defects in a developing foetus.
Chemical mutagen
Cigarette smoke, benzoyl peroxide
Physical mutagens
UV radiation, x-Ray’s
Biological mutagens
Viruses, hepatitis B, Epstein Barr Virus.
Totipotent stem cells
Potential to create any cell necessary.
Before inner cell mass.
Multipotent stem cell
Able to produce cells that have a specific function
Eg. Red blood cell. Umbilical cord
Found in bone morrow.
Pluripotent stem cells.
Able to create most tissues of an organism.
Eg. Inner cell mass.
Germ layer
There are three layers
Endoderm- internal layer
Mesoderm- middle layer
Ectoderm- external layer
Blastocysts
When a zygote does division, after 5 days a hollow ball is formed.
List three courses of stem cells.
Umbilical cord, embrognic stem cell, adult stem cell
Embryonic and adult stem cells.
Embryonic can make any cell.
Stem cell therapy.
Nerve cells- spinal cord injury
Bone marrow cells- cancer patients
Skin cells- burns.
