Download Exam 4 Review - Iowa State University

Worksheet:
Exam 4 Review
Supplemental Instruction
Iowa State University
Leader:
Course:
Instructor:
Date:
Matt
Biol 211 (1)
Biederman
10/26/16
1.) If a species has a 2n number of chromosomes = 16 then which of the following is true?
A) The species is diploid with 32 chromosomes per cell
B) A gamete from this species contains 4 chromosomes
C) Each cell has 8 homologous pairs
D) The species has 16 sets of chromosomes per cell
E) None of the above
Follow up: What is a homologous pair? Only in meiosis. One from dad, one from mom. Same
genes, different alleles.
2.) Which of the following occurs in meiosis but not mitosis?
A) chromosome replication
B) synapsis of chromosomes
C) production of daughter cells
D) alignment of chromosomes at the center of cell
E) condensation of chromatin
3.) A human cell containing 22 autosomes and a Y chromosome is a
A) egg
B) zygote
C) sperm
D) a male somatic cell
E) a female somatic cell
4.) Which of the following happens at the conclusion of meiosis I?
A) homologous chromosomes are separated
B) the chromosome number per cell is conserved
C) sister chromatids are separated
D) four daughter cells are formed
E) the sperm cell fertilizes the egg
5.) A cross between a homozygous purple flowered and a homozygous white flowered pea plants results
in offspring with purple flowers. This demonstrates
A) blending inheritance
B) true breeding traits
C) dominance of one trait over another
D) a di-hybrid cross
E) a mistake by Mendel
6.) When you cross an organism that is homozygous recessive for a trait with one that is a heterozygote
for the same trait, what is the chance of producing homozygous recessive offspring?
A) 0%
B) 25%
C) 50%
D) 75%
E) 100%
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7.) The rare llama-rabbit is known to have 2 traits: head shape (H) and tail length (T) that are controlled
by un-linked genes. The genotype of a stud-male llama-rabbit is HhTt. Which of the following is a
possible genotype found in his gametes?
A) HT
B) Hh
C) HhTt
D) Tt
E) H
8.) An organism’s appearance or observable traits are referred to as its
A) genotype
B) phenotype
C) character
D) trait
E) dominant allele
9.) Red-green color blindness in humans is a sex-linked recessive trait. A husband and a wife with
normal vision have a color-blind son. What are the genotypes of the parents?
A) Xc Xc and XcY
B) Xc Xc and XCY
C) XC XCand XcY
D) XC XC and XCY
E) XC Xc and XCY
The Mitotic Cell Cycle:
H





Label each letter
What is happening to
the chromosomes at
each step?
If letter (I) was
added, what might it
represent?
What letters =
Interphase? Mitosis?
How would a circular
representation of
meiosis differ?
Is binary fission more
similar to mitosis or
meiosis?
Compare and Contrast:
Mitosis:
Meiosis:
What stage do they both start out in?
Interphase G1
What events are unique to this type of cell division?
Can produce diploid cells
What events/structures are unique to this type of cell
division?
Synapsis, prophase 1, homologous pairs stick together,
crossing over, tetrad (homologous pair)
What is the purpose of this type of cell division?
Growth and development
Tissue renewal/repair
What is the purpose of this type of cell division?
Sexual reproduction
Making gametes
Final Product in humans: (Number cells? Ploidy? Relation
to original cell?)
Two diploid cells, identical to parent cell
Final Product in humans: (Number? Ploidy? Relation to
original cell?)
4 haploid cells, genetically distinct
What human cells does this process produce? How
many autosomes/sex chromosomes?
44 autosomes, 2 sex chromosomes
Somatic cells
What human cells does this process produce? How
many autosomes/ sex chromosomes?
22 autosomes, 1 sex chromosome
gametes
What problems can arise?
Uncontrolled replication-tumors
What problems can arise?
Extra or missing chromosomes
Trisomy (down syndrome)
Is genetic variation introduced? How?
Mutation
Is genetic variation introduced? How?
Mixing of genetic material from different parent
cells (bi parental inheritance), crossing over,
mutation
For a good animated overview of Mitosis and Meiosis visit: vcell.ndsu.nodak.edu/animations
Briefly describe the difference between the following:
Genotype vs. Phenotype?
Genotype: types of alleles
Phenotype: physical characteristics
Gene vs. Loci vs. Allele?
Gene: DNA that codes for a trait
Allele: type of gene
Loci: location of gene DNA
Dominant allele vs. Recessive allele?
Dominant: covers up recessive
Recessive: Only shows if only recessive alleles are possessed
Homozygous vs. Heterozygous?
Homo: Has all either dominant or recessive
Hetero: has both dominant and recessive
Are the following homozygous or heterozygous? How many gametes could each produce?
HH
Rr
EeGG
TtAa
RrHHTT
Homozygous
Hetero
Hetero for E
Hetero for T and Hetero R,
1 gamete
2 gametes
Homo for G
A
homo H and T
2 gametes
4 gametes
2 gametes
Punnett Square practice:
1. Albinism (lack of skin pigmentation) is caused by a recessive autosomal allele. Persons who are
heterozygous for albinism are carriers. Persons who are homozygous recessive have the disease.
If a person who does not have the disease and is not a carrier marries a carrier for the disease,
what is the chance they will have a child with the disease? What is the chance they will have a
child who is a carrier? Show the Punnett square to support your answer.
What are the parental genotypes: Are they hetero/homozygous?
One hetero, one homo dominant
How many different gametes can each parent produce:
1 from homozygous, 2 from hetero
2. You have a dog that is homozygous recessive at locus (A) and has light fur. She has 8 puppies that all
express dark fur color. What is most likely the genotype of the father? Show the Punnett square to
support your answer.
What are the parental genotypes: Are they hetero/homozygous?
homozygous
How many different gametes can each parent produce:
1
3.
Sex linked: If the mother is a carrier for colorblindness XCB then what ratio of her children
will be colorblind? (The father is not colorblind.)
4. Dihybrid Crosses:
P: GGDD x ggdd
F1:
F2 (from F1 self):
GD
GgDd
GD
GgDd
GgDd
GgDd
XCBX
XX
XCBY
XY
GD
Gd
gD
gd
GGDD
GGDd
GgDD
GgDd
GGDd
GGdd
GgDd
Ggdd
GgDD
GgDd
ggDd
ggDd
GgDd
Ggdd
ggDd
ggdd
What is it?
Examples?
Polygenic Inheritance
Many genes contributing to
one trait
Skin tone
Incomplete Dominance
blending
RR is red, rr is white, Rr is
pink
Codominance: Equally expressed. Example: RR is red, rr is white, Rr is alternating red and white petals