Note Taking Guide
Topic # 3032
Inheritance
By: Alisa Amy Kowalski
History of Genetics
1670’s
∙
Scientists believed that...
–
Each sperm contained a “little man” that would develop into a human.
–
Mother only served as an ______________________________.
1750’s
∙
Scientists believe in the “Blending of Inheritance Theory”
∙
Example: a black animal mated to a white animal would produce a gray animal
1850’s -________________________ ______________________
∙
Austrian monk
∙
Did a series of experiments that would lead to a new understanding of the mechanism of
inheritance
∙
Worked in the monastery garden mating ____________________________
∙
Determined that characteristics were inherited by discrete factors that would eventually be
known as ______________________
∙
He described the principle of segregation & the principle of independent assortment
Principle of __________________________________
∙
Every individual carries pairs of factors for each trait and that the members of the genes
segregate at random (without specific control or predetermined plan) during the
formation of gametes.
∙
Since segregation is random, predictable ratios of traits are found in the offspring
∙
During segregation chromosomes go from a pair (2n or diploid) to
_________________ (1n or haploid)
∙
Genes do not blend and are passed intact from one generation to the next and
_______________ governs the segregation of the chromosomes in the gametes.
Principle of Independent Assortment
∙
Members of each pair of genes are distributed independently when the gametes are
formed and are ______________________ by other gene pairs on other chromosomes.
∙
When pairs of genes on different chromosomes separate, they have an
____________________________ or probability of going to an individual gamete
∙
There is no __________________________ order for the dividing pairs- its every gene
for itself (genetic variation).
Chromosomes
∙
Located in the _____________________
∙
Contain all of the _____________________________ material in the cell
∙
Chromosomes are arranged in pairs
– ___________________: half the diploid or somatic (non-sex cells or gamete) number
–
of chromosomes (n or 1n)
Diploid: number of chromosomes found in the somatic or body cells
(__________). Also can be considered as twice the number of chromosomes
found in the gametes (sperm or ovum).
Chromosome Numbers
Animal
n
2n
Cattle
30
60
Sheep
27
54
Goat
30
60
Swine
40
80
Horse
30
60
_____________________________________________
Chromosomes are made up of a substance called DNA
DNA
∙
Deoxyribonucleic acid
∙
Made up of three components
–
Deoxyribose sugar
– ___________________________________________________
–
________________________nitrogenous bases
Nucleotides
∙
Combination of deoxyribose, phosphate and one of the four bases
∙
Band together to form _____________ strand of the DNA molecule
∙
Two of these strands wind around each other in a ______________________________ to
form the DNA molecule
The 4 Nucleotides
∙
∙
The bases of the DNA hold the key to inheritance
The four nitrogenous bases are
–
__________________________ (A)
–
__________________________Thymine (T)
–
__________________________(G)
–
__________________________Cytosine (C)
∙
In the two strands of DNA,
–
A is paired with ________
–
__________ is paired with G
Replication of DNA
∙
The double helix _________________ and pulls apart
∙
∙
A new strand is formed using the old strand as a ________________________
The end result are two identical double helix strands
The Gene
∙
Points of ___________________ found in each chromosome that govern the way in
which traits develop.
∙
__________________ areas on each chromosome and are made up of DNA
Genetic Codes & Protein Synthesis
∙
Each different possible code represents a ___________________
∙
RNA (ribonucleic acid) is a group of molecules in charge of reading and translating the
genetic code for the formation of new _________________________.
∙
RNA uses the DNA as a template to read the code in order to produce the right protein
with the correct order and number of amino acids
3 Types of RNA
∙
_____________________ RNA (tRNA)
–
plays a key role in protein synthesis
–
each tRNA molecule can combine with one amino acid and can transport the
amino acid to the new protein building site in the cytoplasm of the cell
∙
_____________________ RNA (rRNA)
–
plays a key role in protein synthesis
–
helps control the connecting of the parts of the protein (the amino acids) together.
_____________________ RNA -mRNA
∙
Helps complete the building of the protein
∙
Physically sequences the amino acids that are carried to the building site by the tRNA &
chemically connected by the rRNA
∙
Directs the sequence base on the order it obtains from the DNA molecules
RNA Transcription
∙
__________ is paired with G
∙
T is paired with ___________
∙
_____________ is paired with U
Comparison to Building a House
∙
tRNA
–
people who haul the building materials to the construction site (cytoplasm - on
the ribosomes)
∙
__________________
–
People that drive the nails, pour the concrete, etc.
∙
mRNA
–
provides a physical pattern or blueprint for construction
∙
DNA –
the original _____________________ that is kept in the main office (nucleus)
that directed the plan
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