genetics vocabulary sbi 3c: november 2012. important terms: genetics: the study of the...
TRANSCRIPT
IMPORTANT TERMS: Genetics:
The study of the relationship between genes and heredity
Mitosis Division of nucleus into two genetically identical nuclei
Meiosis Cell division process that involves two divisions with only
one duplication of chromosomes Parent cell
Cell that divides by mitosis into two genetically identical cells
Daughter cells Genetically identical cells produced from parent cell
IMPORTANT TERMS: Chromatin
Thread-like structure of DNA and proteins in nucleus Chromatid
Each of the two identical chromosome strands in a replicated chromosome attached by their shared centromere
Chromosome Carries genes, formed when chromatin condenses
Chromatid (when together
and chromosome when separated)
IMPORTANT TERMS: Gene
Segment of DNA that carries the code for a specific protein Allele
One form of a gene for specific trait (ex. If gene was eye colour, allele would be blue/brown/green)
Diploid (2n) number of chromosomes in a body cell of an organism, having
two chromosomes of each type per cell Haploid
(n) number of chromosomes in a cell that contains a single set of chromosomes, present in gametes
Somatic cells General body cells, have the diploid number of chromosomes
Sex cells Haploid reproductive cells, sperm and egg, whose union is necessary
in sexual reproduction to initiate the development of a new individual (also called gametes)
Gametes Egg and sperm cells that unite during sexual reproduction
THE CELL CYCLE:
Interphase: in between stages of dividing G1—beginning cell growth S—DNA duplicates (makes a
copy) DNA is in the form of chromatin G2—cell undergoes it’s function
Purpose: to replace dead or dying cells to allow an organism to grow and
develop
interphase
Mitosis animation:http://www.youtube.com/watch?v=AhgRhXl7w_g
MITOSIS:What is it?
DNA copies (chromosomes) are separated & sorted into two sides of the cell
the cell then splits in two and part of each parent is carried to the two new cells.
each ‘daughter’ cell is identical to the parent cell
results in cells such as internal organs, skin, bones, blood, etc.
Interphase occurs just before Mitosis begins:
DNA is replicated along with organelles and other cellular components and the cell prepares for division.
http://www.bioweb.uncc.edu/1110Lab/notes/notes1/lab6.htm
Mitosis Interphase
Animal cell Plant cell
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
STEP 1:Prophase (preparation phase)• the DNA recoils, and the chromosomes
condense• the nuclear membrane disappears• mitotic spindles begin to form
Nuclear membrane
Mitosis Prophase
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
Animal cellAnimal cell Plant cellPlant cell
STEP 2: Metaphase (organizational phase) spindle fibres attach to the chromosomes at
the centromere chromosomes line up the middle of the cell
Mitosis MetaphaseAnimal cell Plant cell
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
STEP 3: Anaphase (separation phase) the chromosomes split at the centromere the ‘sister’ chromatids are pulled by the
spindle fibers to opposite poles of the cell.
Mitosis Anaphase
Plant cell
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
Animal Cell
STEP 4:Telophase the chromosomes, the cytoplasm and organelles divide
into 2 portions. this diagram shows the end of telophase
Mitosis TelophaseAnimal cell Plant cell
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
After Mitosis: Cytokinesis the actual splitting of
the cytoplasm into two separate cells is called cytokinesis
occurs differently in both plant and animal cells
Animal cells: cleavage furrow pinches cell
Plant cells: cell plate forms in between
Beginning of cytokinesis in a plant:
Beginning of cytokinesis in an animal:
http://www.bioweb.uncc.edu/1110Lab/notes/notes1/lab6.htm