Chapter 5, section 1 and 2- Mendel and Heredity Notes
CUE WORDS or QUESTIONS
NOTES WRITTEN

Gregor Mendel- father of modern genetics



Heredity- passing physical traits from parents to offspring
Trait- form of a physical characteristic (like your height or skin color)
Genetics- study of heredity
What is fertilization?




Fertilization- when an egg and sperm unite to form a zygote
P generation- parental generation
F1 generation- first filial (first generation of offspring)
F2 generation- second filial (second generation of offspring)
What is a gene?
What are alleles?



Gene- factor that determines traits (it is a small section of the DNA)
Alleles- different forms of a gene (red, brown, black, blonde, orange)
Traits are determined by alleles that your parents passed on to you
Is there a difference between
dominant and recessive?
 Dominant allele- trait that always shows when present
(represented with a capital letter)
Who is the father of genetics?
X What is genetics?
 Recessive allele- trait that only shows if dominant alleles is not present
(represented with a lower case letter)
X
 An organism inherits one allele from mom, and one from dad
(everyone has two alleles for each gene)
Is there a difference between
purebred and hybrid?


Purebred- organism with two of the same alleles for a trait
Hybrid- organism with two different alleles for a trait
Probability-

Probability- how likely an event will happen
(written in a fraction or a percent)
• ½= ____ %
• ¼= ____ %
How are probabilities of

offspring determined?
SUMMARY
X
Punnett square- chart used to predict probabilities in genetics,
(what the offspring will look like)
CUE WORDS or QUESTIONS
NOTES WRITTEN
Punnett square examples:
X
Your turn:
What is the difference between
phenotype and genotype?
X
What is the difference between
heterozygous and
homozygous?
 Genotype- genetic makeup (it is the allele pair, so it is represented
with two letters)
 Phenotype- physical appearance (what an organism looks like,
..\student\genotype
and phenotype.pptx
based on their genotype)
 Homozygous- organism that has identical alleles
(also called purebred)
• Example genotype- BB or bb
 Heterozygous- organism that has two different alleles
(also called hybrid)
• Example genotype- Bb
SUMMARY
X