Transcript Intro to Genetics

Intro to Genetics
1. Define the following terms:
Genetics- • The study of HOW traits are
passed from parent to offspring.
Traits- INHERITED characteristics/traits
Heredity-
• Passing of traits from parents to
offspring
Gene- •
1 unit of code to a characteristic
Allele-
• DIFFERENT forms of one unit.
2. Which allele can hide the presence of any
other allele? How do we identify that
allele when writing out the genotype?
• -dominant
• -capital letter
3. What allele can be hidden? How
do we identify that allele when
writing out a genotype?
• -recessive
• -lowercase letter
4. How many alleles usually make
up a genotype?
2
5. If “B” is brown and “b”
is blonde. Write the
genotype and identify the
phenotype for:
Heterozygous- • Bb-brown
Homozygous
• bb-blonde
recessiveHomozygous
• BB-brown
dominant-
6. In a homozygous genotype the
alleles are both the same.
7. What is another name for
homozygous?
• purebred
8. In a heterozygous genotype the
alleles are different.
9. What is another name for
heterozygous?
• hybrid
10. Can we see the phenotype or
the genotype?
• phenotype
11. Who is the “Father of Genetics”
who studied pea plants?
• Gregor Mendel
12. Mendel had 3 conclusions; the
first was that every trait has
how many factors/alleles?
• 2
13. Mendel’s 2nd conclusion was the Law
segregation
of ___________
where 2 factors/alleles
for each trait separate during gamete
anaphase I and __________
anaphase II
formation in _________
of meiosis.
14. Mendel’s 3rd
conclusion was the
Independent
Law of ___________
Assortment
___________, this is
when factors/alleles
for different
characteristics
separate randomly
__________
during ____________
metaphase I
anaphase I
and_____________of
meiosis.
15. What do we use to predict the
traits of offspring?
• Punnett Squares
16. If we don’t know the genotype of an
organism displaying a dominant trait, we
test cross to identify the
can use a __________
unknown allele (we already know one allele is
dominant because the trait is being displayed)
17. Complete the following test crosses and identify the
parent as either homozygous dominant or
heterozygous. The one parent demonstrates a
dominant phenotype. (Cross this unknown
dominant phenotype with a known genotype to
complete the following Punnett Squares)
b
Bb
Bb
Bb
Bb
bb
bb
Bb
Bb
B
Unknown parent-Bb
Unknown parent-BB
Heterozygous
Homozygous dominant
18. What are most traits?
• polygenic
19. Define and give an example for:
Polygenic trait-• trait controlled by 2 or more
pairs of alleles ex. Hair color
19.cont.
•
traits
controlled
by
3
or
Multiple alleles:
more alleles ex. Blood type
19. cont.
Codominance:•
both alleles are expressed in
phenotype ex. Black + white=
spotted
19. cont.
Incomplete • heterozygote genotype makes
a 3rd phenotype ex. Red +
dominance: white=pink
20. What 3 things does genetic
engineering do between two
organisms?
• -identify genes
• -manipulate genes
• -transfer genes
21. DNA that is a combination of
two different sources is called?
• Recombinant DNA
22. When DNA is combined from two
different sources, what kind of
organism does it produce?
• Transgenic organism
23. What are the 4 main practical
reasons for genetic
engineering?
•
•
•
•
-medicine
-vaccines
-Food & crops
-Plants
24. What is a benefit of genetically
engineering medications?
• Lowers cost
25. What is a benefit of genetically
engineering vaccines?
• Virus prevention
26. What are three possible
benefits to genetic engineering
of food?
• -ripen faster
• -combination of 2 foods
• -add vitamins and nutrients
27. What are three benefits to
genetically altering plants?
– -to be resistant to pesticides
– -be toxic to insects
– -no or less need to fertilize or soil
28. Give me a controversial genetic
engineering topic and explain if you
agree or disagree.
• Cloning- answers vary
29 &30. Make Punnett squares for the
following and give the fraction of
dominate phenotypes and the
percentage of recessive phenotypes.
• Parents:
EE & Ee
4/4 dominant
phenotype
0% recessive
phenotype
E
E
e
E
EE
EE
Ee
Ee
29 & 30 cont. Parents: Ff & Ff
¾ dominant
phenotype
F
f
25% recessive
phenotype
F
FF
Ff
f
Ff
ff
29 &30 cont. Parents: RR & rr
R
4/4 dominant
phenotype
R
r
Rr
Rr
r
Rr
Rr
0% recessive
phenotype