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THURSDAY, NOVEMBER 20, 2014
Agenda:
The Work of Gregor Mendel and Observing Human Traits Lab
Learning Objective: Students will analyze and interpret data
from observing different human traits within a classroom.
HW: Review your notes so far (all ppts posted on website).
11-1: THE WORK OF
GREGOR MENDEL
GENETICS
¡ S cientific study of heredity
§ H eredity: the passing on of characteristics
genetically from one generation to another.
GREGOR MENDEL
¡ F irst person to succeed in predicting
how traits are transferred from one
generation to the next.
§ S tudied pea plants, which have both male
and female reproductive parts, producing
pollen and eggs respectively and are capable
of self and cross-pollination.
TRUE-BREEDING A.K.A. PUREBRED
¡ O rganisms that produce offspring
identical to themselves if allowed to selfpollinate.
HYBRIDS
¡ O ffspring crosses between parents with
different traits
THINK-PAIR-SHARE
¡ W ith your partner, think of 1 organism
that is purebred and write down a
justification for why it is purebred.
¡ T hink of another organism that is a
hybrid and write down a justification for
why it is a hybrid.
TRAIT
¡ S pecific characteristic that varies from one
individual to another.
§ Mendel studied 7 traits with 2 contrasting
characters.
MENDEL’S WORK
¡ Mendel crossed plants with each of the 7 contrasting
characters and studied their offspring.
§  P- parental generation, the original pair of plants.
§  F 1 - 1 st generation: offspring of the parents
§  F 2 - 2 nd generation: produced by crossing members of the F 1
generation
MENDEL’S CONCLUSION
1.  Biological inheritance is determined by
factors that are passed from one generation
to the next.
Genes: the chemical factors that determine traits
Alleles: the different forms of a gene
§ 
§ 
§ 
Ex. T or t, S or s, P or p etc.
2.  The principle of dominance states that some
alleles are dominant and others are
recessive.
THINK-PAIR-SHARE
Why do you think it’s possible
to look more like your
grandparents but not like your
parents?
F 1 SELF POLLINATION PRODUCES F 2 :
MENDEL CONCLUDED
¡ A dominant allele masked a recessive
allele in the F 1 generation.
¡ A t some point the recessive allele was
separated or segregated from the
dominant allele.
¡ T his segregation occurred during the
formation of gametes (sex cells).
EXIT SLIP
¡ B .socrative.com
¡ C lass: 642668
¡ H ow do the traits we observed in
class today represent a diverse
genetic pool present within our own
classroom? Why is genetic variation
important?
SEGREGATION*
¡ When each F 1 plant flowers, the two alleles are
segregated from each other so that each gamete
carries only a single copy of each gene.
¡ Therefore, each F 1 plant produces 2 types of
gametes– those with the dominant allele and those
with the recessive allele.