BIO 180. PROBLEM SET
INSTITUTE OF BIOLOGY, UP DILIMAN
1. In how many ways can 20 different amino acids be arranged
into a polypeptide chain of 10 amino acids IF:
a. Each amino acid can only be used once
b. Each amino acid can be used more than once
2. Given the following blood types and their frequency:
Blood Type Frequency
O 2000
A 1500
B 1000
AB 500
a. Calculate the relative frequency of each blood type
b. In this particular population, what is the probability that
when you encountering four individuals, the
first one is type O, the second one is type A, the third one is
type B, and the fourth one is type AB?
3. In humans, there are 23 pairs of chromosomes in a diploid
cell. In each of the pairs, one chromosome came
from the mother and one from the father. During meiosis, each
pair of chromosomes segregates to form
haploid gametes of 23 chromosomes. The assortment of the 23
chromosomes is independent of each other.
a. How many gametes are possible for an individual to produce by
assortment of chromosomes?
b. What is the probability that a gamete would consist of 23
chromosomes that all came from the
individuals father?
c. For each gamete, what is the probability that 9 chromosomes
came from the father and 14 from the
mother?
4. Either allele A or a may occur at a particular gene locus. An
offspring receives one of its alleles from each of
its parents. If one parent possesses alleles A and a and the
other parent possesses a and a:
a. What is the probability of an offspring receiving an A and
a?
b. What is the probability of an offspring receiving two a
alleles?
c. What is the probability of an offspring receiving two A
alleles?
5. In an experimental garden, you have 10 plants that are purple
flowered and 5 plants that are white flowered.
You randomly select 5 plants.
a. What is the probability of getting all white flowers?
b. What is the probability of getting all purple flowers?
c. What is the probability of getting 3 plants with purple and 2
plant with white flowers?
6. If the odds AGAINST an organisms survival are 4:6, what is
the probability of its survival?
7. In one area occupied by the African land snail Achatina
fulica, 50% are infected with lungworms while 30%
are infected with hookworms. 20% are infected with both.
a. What percentage of snails are those infected by lungworms
only?
b. What percentage of snails are those infected by hookworms
only?
c. What percentage of snails are those not infected by any
parasite?
d. What is the probability of randomly selecting an infected
snail?
e. If a snail is infected by a lungworm, what is the probability
of it being infected also by a hookworm?
f. Is the presence of the two parasites independent of each
other?
8. Given the following data set of number of parasites per
infected individual, construct a frequency histogram
and a box plot.
95 43 82 90
42 92 69 96
19 21 89 97
95 8 88 84
82 33 59 83
Name: _____________________
1. Amino acid
a. __________________________________________
b. __________________________________________
2. Blood Type
a. __________________________________________
b. __________________________________________
3. Human Chromosomes
a. __________________________________________
b. __________________________________________
c. __________________________________________
4. Alleles
a. __________________________________________
b. __________________________________________
c. __________________________________________
5. Flowered plants
a. __________________________________________
b. __________________________________________
c. __________________________________________
6. Survival
__________________________________________
7. Snail-parasite
a. __________________________________________
b. __________________________________________
c. __________________________________________
d. __________________________________________
e. __________________________________________
f. __________________________________________
8. Frequency histogram
Box Plot
