Cell Growth And Division Flashcards
Asexual reproduction
Produces identical offspring from 1 parent
Sexual reproduction
Produces genetically diverse offspring from 2 parents
Sexual reproduction advantages/disadvantages
Advantages-changing environments
Disadvantages- it takes a long time to find a mate
Asexual reproduction advantages and disadvantages
Advantages- stable environment, reproduce faster
Disadvantages- changing environments all organisms equally susceptible
What is chromatin
Uncoiled DNA and proteins
What must happen to chromatin before cell division
It must be packaged into chromosomes
How are chromosomes formed in eukaryotes
DNA wraps around histomes
Only visible during cell division
Prokaryote chromosomes
Single circular chromosome
Eukaryotes chromosomes
Multiple linear chromosomes
How many chromosomes are found in somatic cells
46
44 are autosomes
2 are sex chromosomes
XX vs XY
XX is female
XY is male
How many chromosomes do sex cells have
23
What are the cell cycle stages
Interphase, mitosis, cytokinesis
What regulates the cell cycle
How
Cyclin
As the amount of Cyclin rises, the cell goes into the next phase
How did they discover cyclin
Injecting cyclin into non-dividing cells which then made spindle fibers
Ex of internal regulators
Some don’t allow mitosis to begin until all chromosomes have been copied
Some don’t allow anaphase to begin until spindle fibers attach to each chromosome
Why are growth factors important
They speed up cell division in embryonic development/ healing
What is apoptosis and what is the process
Programmed cell death
Cell and chromatin shrink
Parts of the cell membrane break apart
Neighboring cells get rid of the remains
What is cancer
A disorder in which some of the body cells loose the ability to control growth
What is a tumor
A mass of cancer cells
What are benign tumors
Cells remain in mass, normally harmless unless they became so large that they interfere with organs
Example: fibroid cysts
Malignant tumors
Cells invade and destroy healthy tissue elsewhere in the body
What is matastasis
The spread of cancer from its original source
Cells break away from original mass and travel to other parts of the body
What is cancer categorized by
The type of tissue it affects
Carcinomas
Grow in skin/ organ lining tissue
I.e. Lung and breast cancer
Sarcomas
Tumors that grow in bone/ muscle tissue
Lymphomas
Solid tumors that grow in tissues that form blood cells
Many cause leukemia
What causes cancer
Mutations in genes that can occur spontaneously or due to carcinogens
Some bacteria and viruses
Treatments of cancer
Surgery, radiation, chemotherapy
How to identify a mole
Asymmetry, border, color, diameter, evolving
Why are cells small
1 information overload- not enough DNA to meet the demands of a large cell
2 surface area to volume ratio- cell can’t get enough materials in and out
Interphase
Longest stage divided into 3 parts
G1
Growth, cell does its job(makes proteins)
S (synthesis)
DNA is copied
G2
Copies organelles
G0
Non dividing phase
Mitosis
Prophase, metaphase, anaphase, telophase
Prophase
Chromatin could into chromosomes
Nuclear membrane/ nucleoli a break apart
Centrioles move to opp sides of cell and make spindle fibers which attach to each centromere
Metaphase
Spindle fibers move chromosomes to line up in a single line called the equator
Anaphase
Spindle fibers pull centromere apart allowing chromosomes to split apart
Stops when they reach the poles
Telophase
Me clear membrane/ nucleoli a reform, chromosomes uncoil into chromatin, and spindle fibers break apart
Cytokinesis
Division of cytoplasm
Cytokinesis in animal cells
Along cleavage furrow
Cytokinesis in plant cells
Formed by a cell plate which is made by the Golgi apparatus
End product
2 daughter cells
