Biology for IGCSE & O level - Inheritance (Section 11)
1
What is the sex chromosome composition of a normal human male?
Answer
(B)
XY
2
What is the expected genotypic ratio from a monohybrid cross (Aa x Aa)?
Answer
(C)
1:2:1
3
What does the principle of independent assortment state?
Answer
(B)
Alleles for different traits are inherited independently of each other.
4
What is the name for a diagram that shows the inheritance of a trait through several generations of a family?
Answer
(B)
Pedigree
5
What is a codon made of?
Answer
(C)
3 nucleotides
6
What is the name for the pairing of homologous chromosomes during meiosis?
Answer
(A)
Synapsis
7
Which of the following are true regarding genes and alleles?
Answer
A
D
8
What is the role of the centromere in a chromosome?
Answer
(B)
To hold sister chromatids together.
9
Which of the following is a characteristic of sex-linked traits?
Answer
(C)
They are more common in males.
10
What type of inheritance is most likely to affect males more often than females?
Answer
(D)
X-linked recessive
11
What are the main events of Meiosis II?
Answer
(C)
Separation of sister chromatids
12
What is the expected phenotypic ratio of offspring from a monohybrid cross (Bb x Bb) with complete dominance?
Answer
(B)
3:1
13
What is a monohybrid cross?
Answer
(A)
A cross between two individuals that differ in one trait.
14
Which of the following scenarios could result in the formation of a new allele?
Answer
A
D
15
Which of the following would be the correct genotype for a female carrier of an X-linked recessive trait?
Answer
(D)
XBXb
16
What does the term "carrier" refer to in genetics?
Answer
(C)
An individual who carries a recessive allele but does not show the trait.
17
Which of the following statements are true regarding the inheritance of a trait from the perspective of a pedigree diagram?
Answer
(A)
A shaded shape indicates that the individual has the trait.
18
What does a recessive allele require to express its phenotype?
Answer
(B)
Two copies of the same allele.
19
What is the relationship between genes and chromosomes?
Answer
A
C
D
20
In a pedigree, what shape is used to represent a male?
Answer
(B)
Square
21
What is the process of forming a protein from a mRNA sequence called?
Answer
(B)
Translation
22
What is the difference between mitosis and meiosis?
Answer
(B)
Mitosis produces genetically identical cells while meiosis produces genetically different cells.
23
What are the products of transcription?
Answer
(C)
mRNA
24
In a cross between a homozygous dominant individual and a homozygous recessive individual for a single trait, what is the genotypic ratio of the offspring?
Answer
(D)
4:0
25
If a plant has a genotype of Tt for plant height, what is its phenotype?
Answer
(A)
Tall
26
Which of the following inheritance patterns involves genes located on the sex chromosomes?
Answer
(B)
X-linked inheritance
27
What is a karyotype?
Answer
(A)
A visual representation of all the chromosomes in a cell.
28
Which of the following are characteristics of homologous chromosomes? (Select all that apply)
Answer
A
D
29
Which of the following is NOT a base found in DNA?
Answer
(D)
Uracil
30
Which of the following processes is involved in asexual reproduction? (Select all that apply)
Answer
A
C
31
If a man with normal color vision has a child with a woman who is a carrier for red-green color blindness, what is the probability that their son will be colorblind (assuming colorblindness is X-linked)?
Answer
(C)
50%
32
What is the role of spindle fibers?
Answer
(C)
To separate chromosomes
33
What is the process that produces gametes?
Answer
(B)
Meiosis
34
What type of inheritance is exemplified by the ABO blood group system?
Answer
(C)
Codominance
35
What is the phenotypic ratio expected from a cross between two heterozygous individuals (Aa x Aa)?
Answer
(B)
3:1
36
What is the process in which mRNA is created?
Answer
(A)
Transcription
37
If a trait is autosomal recessive, what is the expected phenotype of an individual with the genotype Aa?
Answer
(A)
The dominant phenotype.
38
What is the function of the spindle fibers during cell division?
Answer
(B)
To separate sister chromatids.
39
Which of the following statements correctly describes the relationship between DNA, genes, and proteins? (Select all that apply)
Answer
A
B
D
40
What is the genotype for an individual that is heterozygous for two traits? (e.g., seed shape and seed color)
Answer
(B)
AaBb
41
What is the function of a gene?
Answer
(B)
To code for a specific protein.
42
Which of the following is a difference between mitosis and meiosis?
Answer
(A)
Mitosis occurs only in somatic cells while Meiosis only occurs in gametes.
43
What is the probability of getting a child with an X-linked recessive disorder if the mother is a carrier and the father is unaffected?
Answer
(B)
25%
44
Which of the following is an example of codominance?
Answer
(A)
ABO blood type
45
If a woman is a carrier for an X-linked recessive trait and her partner has the trait, what is the probability that their daughter will have the trait?
Answer
(C)
50%
46
If two heterozygous individuals are crossed (e.g., Gg x Gg), what proportion of the offspring will show the recessive phenotype?
Answer
(B)
25%
47
During which phase of mitosis do the sister chromatids separate?
Answer
(C)
Anaphase
48
Which of the following statements about DNA is correct?
Answer
(D)
DNA contains the base thymine.
49
If a woman is colorblind and her partner has normal vision, what is the probability of their son being colorblind (assuming colorblindness is X-linked recessive)?
