Transcript 1 - Answer

Chapter 5
(Sections 1 & 2)
Heredity
Review Game
1
An organism with two
dominant alleles or two
recessive alleles is called
______________.
1 - Answer
An organism with two
dominant alleles or two
recessive alleles is called
homozygous OR purebred.
2
A feature that has
different forms in a
population is called a
______________.
2 - Answer
A feature that has
different forms in a
population is called a
characteristic.
3
Who is the scientist that
studied pea plants to
determine how traits are
passed from parents to
offspring?
3 - Answer
Who is the scientist that
studied pea plants to
determine how traits are
passed from parents to
offspring?
A: Gregor Mendel
Draw a punnett square
labeled like this:
Male
Female
4
4
Fill in your punnett square
for the following scenario:
4
A zoo keeper wants to know
the chance that a baby
giraffe will have a long neck.
The mom is heterozygous for
a long neck, and the dad is
homozygous for a short neck.
Use “L” and “l” to represent
the alleles.
4 - Answer
Female
Your punnett square should look
like this:
Male
l
l
L
Ll
Ll
l
ll
ll
5
Look at your punnett
square. What is the
probability that the baby
giraffe will be a purebred?
Write the genotype(s) of
the purebred offspring.
5 - Answer
Look at your punnett
square. What is the
probability that the baby
giraffe will be a purebred?
A: 50%, or 2 out of 4 (ll)
6
List the 4 exceptions to
Mendel’s findings.
6 - Answer
4 exceptions:
1. Incomplete dominance
2.One gene influences many
traits
3.Many genes influence one
trait
4.Environmental Factors
7
A purebred blue flower
and a purebred yellow
flower are crossed. All of
the offspring are green.
This is an example of
what?
7 - Answer
A purebred blue flower
and a purebred yellow
flower are crossed. All of
the offspring are green.
This is an example of
what? Incomplete
Dominance
8
Female
B
B
b
BB
Male
b
Bb
B = Brown hair
b = blond hair
Bb
bb
If this couple has 4 kids, will
3 of them definitely have
brown hair and 1 definitely
have blond hair?
Female
8 - Answer
B
b
B
BB
Male
b
Bb
B = Brown hair
b = blond hair
Bb
bb
If this couple has 4 kids, will 3 of
them definitely have brown hair and 1
definitely have blond hair? A: No
9
Female
B
B
b
BB
Male
b
Bb
B = Brown hair
b = blond hair
Bb
bb
List the possible genotypes and
phenotypes of this couple’s
children. List genotypes first and
then the phenotype.
9 – Cont.
Label your board like this:
Genotype
Phenotype
**Make sure the genotype matches the proper
phenotype!
Female
9 - Answer
B
b
B
Male
BB
b
Bb
B = Brown hair
b = Blond hair
Bb
Genotype
BB
–
Bb
–
bb
–
bb
Phenotype
Brown hair
Brown hair
Blond hair
10
Female
B
B
b
BB
Male
b
Bb
B = Brown hair
b = blond hair
Bb
bb
What is the probability that this
couple will have a hybrid child? List
the genotype(s) of the hybrid
offspring.
Female
10 - Answer
B
b
Male
B
BB
b
Bb
B = Brown hair
b = blond hair
Bb
bb
What is the probability that this
couple will have a hybrid child? List the
genotype(s) of the hybrid offspring.
A: 50% - Bb, Bb
11
An child with albinism has
skin without pigment and
blue eyes. Both of these
traits are determined by one
set of instructions. This is an
example of which exception
to Mendel’s findings?
11 - Answer
An child with albinism has
skin without pigment and
blue eyes. Both of these
traits are determined by
one set of instructions. This
is an example of which
exception to Mendel’s
findings?
A: One gene, many traits
12
What is the name of the
trait that always shows up,
if it is present?
12 - Answer
What is the name of the
trait that always shows up,
if it is present?
A: Dominant
13
What is the only
combination of alleles that
will show the recessive
trait?
13 - Answer
What is the only
combination of alleles that
will show the recessive
trait?
A: homozygous recessive
OR purebred recessive
14
What would you call an
organism that shows the
dominant trait? List all
possibilities.
14 - Answer
What would you call an
organism that shows the
dominant trait? List all
possibilities.
A: Homozygous dominant
(purebred dominant) and
heterozygous (or hybrid)
15
Using the letter “R” to
represent an allele, list
the 3 possible
combinations of alleles.
15 - Answer
Using the letter “R” to
represent an allele, list
the 3 possible
combinations of alleles.
A: RR, Rr, rr
16
Claire has curly hair which
is a recessive trait (h).
What is Claire’s
phenotype?
16 - Answer
Claire has curly hair which
is a recessive trait (h).
What is Claire’s
phenotype?
A: curly hair
17
Claire has curly hair which
is a recessive trait (h).
What is Claire’s genotype?
17 - Answer
Claire has curly hair which
is a recessive trait (h).
What is Claire’s genotype?
A: hh
18
Curly haired Claire falls in
love with homozygous
Henry who has straight
hair (H). Will any of their
children be purebred?
Claire
18 - Answer
h
h
H
Henry
Hh
Hh
H
Hh
Hh
H = Straight hair
h = curly hair
A: No. 100% of their children will be hybrid
and will have straight hair.
19
In Mendel’s experiments,
what percent of the
offspring in the first
generation showed the
dominant trait?
19 - Answer
In Mendel’s experiments, what
percent of the offspring in the
first generation showed the
dominant trait?
A: 100% - all of the
offspring were purple
EXTRA CREDIT ALERT
To receive 5 points of extra credit on the test,
write down the answers to the questions on this
slide and the next on a piece of notebook paper,
and turn it in on Monday. Your answers must be
correct to receive credit. You may check your
answers with your teacher before school on
Monday.
1. What are the 4 exceptions to Mendel’s principles? AND
Give an example of each exception from your textbook.
2. What is the name of the trait that always shows up if it is
present?
3. What is the term for a feature that shows up in a population
and has different forms?
EXTRA CREDIT ALERT (Continued)
4. What is the term for the different forms of a feature?
5. Draw and label a punnett square. Fill it in with a cross
between a homozygous dominant female and a
heterozygous male. Use the letter “T” to represent the
alleles.
6. What are the two combinations of alleles that would show
the dominant trait?
7. What is the only combination of alleles that would show
the recessive trait?
8. What is a synonym (means the same thing as) for
heterozygous?
9. What is a synonym (means the same thing as) for
homozygous?
10. Write the definition for heredity.
20
In Mendel’s experiments,
what percent of the
offspring in the first
generation carried the
recessive allele?
20 - Answer
In Mendel’s experiments, what
percent of the offspring in the
first generation carried the
recessive allele?
A: 100% - All of the plants
had the genotype Pp, and
“p” is the recessive allele
21
Different forms of a
characteristic are called
________.
21 - Answer
Different forms of a
characteristic are called
traits.
22
What happened to the
recessive traits in the
second generation of
Mendel’s experiments?
22 - Answer
What happened to the recessive
traits in the second generation of
Mendel’s experiments?
A: They reappeared in 1
out of 4 plants, or 25% of
the plants
23
What is heredity?
23 - Answer
What is heredity?
A: Traits passing from
parents to offspring
24
The allele for freckles is
(f). Suppose two nonfreckled parents have 4
non-freckled children and
1 freckled child. What are
the genotypes of the
parents?
Female
24 - Answer
F
f
F
FF
Ff
Male
f
Ff
ff
F = No freckles
f = freckles
A: Since both parents have no freckles,
there are only 2 possible combinations: FF or
Ff. Both parents have to be heterozygous
(Ff) in order to have a child that has shows
the recessive trait of freckles.
Female
24 – Answer,
Male
F
cont.
F
f
FF
Ff
F
FF
Ff
F = No freckles
f = freckles
A: If either parent is homozygous dominant
(FF), all children would show the dominant
trait of no freckles.