GENETICS UNIT Flashcards PreviewGENETICS UNIT Flashcards Preview
Nucleus
membrane bound control center of
cell containing X-shaped structures called
chromosomes. Each chromosome consists
of two chromatids held together by a
centromere.
Chromosome
X-shaped structure
consisting of a single DNA molecule.
DNA Molecule:
A
consisting of genes, the
“code of life”
Organism
½ genes mom + ½ genes dad
Interphase
chromosomes can not be seen;
doubling of chromosomes; nuclear membrane
present; 99% of cell life.
Prophase:
A
spindle fibers form; chromosomes seen
(randomly arranged).
Metaphase
A
chromosomes line up in the Middle,
no nuclear membrane.
Anaphase
chromosomes move Apart (Away)
Telophase
Two joined cells; two nuclear
membranes form
Cytokinesis
Two separated daughter cells form.
Cell Division:
growth (embryo, fetus, infancy → adulthood) and
repair/maintanence of an organism
Asexual Reproduction (ex: bacteria, hydra, worms):
simple life
1 parent / 2 daughter cells
parent/daughter cells identical appearance
parent/daughter
cell same number of
chromosomes
Sexual Reproduction (ex: animals, angiosperms)
A
Two parents (male, female)
daughter cells are a mixture/combination of
genes compared to parent cell (by crossover)
parent to daughter
cell different number
of chromosomes
Parent
2x chromosomes compared to
daughter cells
Daughter
half (½) chromosomes
compared to parent cell
Organism
½ alleles mom; ½ alleles dad “stronger ”
Variation
provides choices for SURVIVAL !!
Variety
allows the organism to be
better adapted to a changing environment.
Mixture of our parents
(our dominant traits are usually
shown; only if both parents have recessive alleles will trait
be shown)
Cancer
abnormal cell division; uncontrolled
mitosis; certain DNA mutations cause cells to
divide in an uncontrolled way.
CAUSE
Mutations are caused by:
1] Chemicals (carcinogens; ex: smoking,
gasoline, alcohol, fried foods)
2] Radiation (high dose; atomic bomb, nuclear
reactor meltdown Chernobyl (for Simon),
Ukraine)
