genetics & heredity. sex cells female ovum or egg malesperm
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ChromosomesChromosomes
A.A. Chromosomes are Chromosomes are rod shaped chemical rod shaped chemical compounds that compounds that carry genetic coding.carry genetic coding.
B. The genetic coding B. The genetic coding transmits transmits characteristics from characteristics from the parent to the the parent to the child.child.
ChromosomesChromosomes
C.C. Found in both sperm and ovumFound in both sperm and ovum
D.D. Every cell has 23 pairs of Every cell has 23 pairs of chromosomes, 46 totalchromosomes, 46 total
E.E. Sperm and ovum contain 23 Sperm and ovum contain 23 chromosomes each.chromosomes each.
GenesGenes
A.A. There are There are hundreds of hundreds of genes on each genes on each chromosome. chromosome.
B. They carry B. They carry individual, individual, specific traits.specific traits.
GenesGenes
C.C. They are the They are the building blocks building blocks of of chromosomes.chromosomes.
D. They are bead-D. They are bead-like structures.like structures.
GenesGenes
E. E. They can be They can be dominant dominant (stronger) (stronger) genes which genes which produce the produce the characteristic characteristic in the in the individualindividual
Blue Eyes
GenesGenes
F. F. They can be They can be recessive recessive (weaker) genes (weaker) genes which do not which do not produce the produce the characteristic characteristic unless unless transmitted by transmitted by both parents.both parents.Red Hair
Genetic InformationGenetic Information
A.A. An XY An XY combination will combination will produce a male produce a male child.child.
B.B. An XX An XX combination will combination will produce a female produce a female child.child.
Genetic InformationGenetic Information
C. The father C. The father determines determines the sex of the sex of the child. the child.
Genetic InformationGenetic Information
D.D. Sex linked Sex linked defects defects
Female is Female is carrier but carrier but defect appears defect appears in male.in male.
Color Blindness
Can you trace a line from one x to the other
x?
FRATERNAL TWINSFRATERNAL TWINS
Form when Form when two eggstwo eggs are are
released at the same time released at the same time andand
each is each is fertilizedfertilized. They grow . They grow
side by side in the uterus. side by side in the uterus.
Because they are the result of Because they are the result of
two different two different ovumovum and and
spermsperm they are no more alike they are no more alike
in terms of heredity than in terms of heredity than
other siblings. They may be other siblings. They may be
of opposite of opposite sexes.sexes.
IDENTICAL TWINSIDENTICAL TWINS
A A fertilized eggfertilized egg starts growing by starts growing by
dividing into dividing into two cells.two cells. These cells These cells
continue to divide. Sometimes, continue to divide. Sometimes,
the cell mass splits in half soon the cell mass splits in half soon
after fertilization. Each cell mass after fertilization. Each cell mass
grows into a separate grows into a separate embryoembryo. .
They are always the They are always the same sexsame sex, and , and
have very similar characteristics have very similar characteristics
because they began as one zygote.because they began as one zygote.
TRIPLETSTRIPLETS
* Triplets can occur through * Triplets can occur through several combinations. several combinations. ThreeThree separate ovum could be separate ovum could be releasedreleased and and fertilizedfertilized. .
* Two ovum could be released, * Two ovum could be released, fertilized and then one ovum fertilized and then one ovum splitssplits into separate into separate embryoembryo, , resulting in a set of identical resulting in a set of identical twins and one fraternal twin.twins and one fraternal twin.
* One * One ovumovum could split into could split into twotwo parts resulting in identical parts resulting in identical triplets triplets
CONJOINED TWINSCONJOINED TWINS
Conjoined twins result Conjoined twins result when when
a a fertilizedfertilized ovum begins to ovum begins to
split into split into twotwo parts, but parts, but does does
not fully not fully completecomplete the the
process. The babies are process. The babies are joined joined
at whatever location does at whatever location does
not not completecomplete the the splittingsplitting
process.process.