genetics developed from curiosity about inheritance genetics … · genetics notes – review book...
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GENETICS Notes – Review book Topic 3 Name ____________________
Genetics developed from curiosity about inheritance.
Genetics: The study of ______________________ (how traits are passed from one generation to the next
(inherited)
An ____________________trait of an individual can be determined by one genes, but is usually
determined by the interaction of many different genes…
_____________; A specific characteristic of an organism. Example: Flower color, eye color
• Cystic fibrosis, skin color, ___________________________________
Gregor _______________ - “Father of Genetics”- discovered that “factors” or alleles are
___________________ from parent to offspring; breeding _________________________________
Mendel’s Principles
1. During ____________________ (making gametes), the arms
of the chromosomes “_____________________________”
and __________________ increasing the genetic
possibilities of the offspring
2. When egg and sperm unite to form a zygote, their alleles
recombine and new combinations are formed - ________________________________________
Genes: segments of DNA that contain instructions to make _____________________
Each _________________ carries a separate piece of information
Hereditary information is contained in ________________, which are composed of ____________,
located in the _________________ of each cell. Chromosomes are found in the ________________of
each cell.
Gene Chromosome Theory
• Genes exist at definite loci in linear sequence on a ______________________and are found in
______________________________.
• Chromosome→ ________________ → ____________ → alleles→ ___________________
Mendel discovered that inheritance follows rules of chance.
________________: Alternate forms or __________________of a gene
Slightly different DNA codes and occur at the __________ location on
________________________ chromosomes
1. Dominant allele: The version of the gene that is expressed (observed) when both alleles are present.
o Symbolized with a ____________________ letter: Ex: A
2. Recessive allele: The version of the gene that is not expressed (not observed) when both alleles are
present. Symbolized with a _____________________________ letter: Ex: a
Genotype: The ________________________make-up of an individual.
The _______________________of the 2 alleles an individual has for a particular trait. Ex: AA, Aa, aa
1. Homozygous (______________) dominant - both ___________________genes are present. EX. AA
2. Homozygous (SAME) recessive – both _____________________ genes are present. Ex. aa
3. _________________________ – (hybrid) one dominant gene and one recessive gene are present. Ex. Aa
Carrier: Any individual who is __________________________________ for a trait.
They “carry” the _______________________________.
Phenotype: The ___________________________ aspects of a genotype
the ________________________characteristics
• The way a _____________________________________ is expressed/described.
Genotype -vs- Phenotype
TT tall pea plant (______________________________________________)
Tt tall pea plant (_______________________________________________)
tt dwarf pea plant (_____________________________________________)
A Punnett square is used to show the possible offspring _______________________
• Mendel’s Pea plants: tall (TT) –vs-. dwarf (tt) pea plants
• Gentotype:
• Phenotype:
I. DNA ___________________________
A. Building _____________________ =
1. ___________________________! (nucleotide)
2. Also known as _______________________
B. _____________________ (4 of them)
1. Each _______________ acid is made of _____ parts:
a) ___________ (________________________)
b) P____________________
c) ____ of 4 _________________ Bases:
(1) _____ = ___________
(2) _____ = ___________
(3) _____= ___________
(4) _____= ___________
C. DNA Shape
1. DNA IS ___________ _____________
2. _____________ TWIST TO FORM ___________- ____________
3. NITROGEN ___________ __________ TOGETHER TO MAKE _______ STRANDS
______ always binds with ______
______ always binds with ______
• A_______ T____________ G__ _C___________
• THIS IS CALLED _______________________________
Let’s Practice!
One strand of DNA has the sequence you see. What is the complimentary strand’s sequence???
G
G
T
A
C
G
C
C
T
II. DNA Replication ( _____________)
A. When does DNA need to be copied????
1. BEFORE any ________ _____________! (________________________________)
B. First, __________________________
C. Second, _____________ bring new _______________ to these strands (______________)
D. Third, you end up with ______________________________
E. DNA acts as a _________________or ____________________to make copies of itself!