Biology for IGCSE & O level - Inheritance (Section 11)
1
What is the sex chromosome composition of a normal human male?
Răspuns
(B)
XY
2
What is the expected genotypic ratio from a monohybrid cross (Aa x Aa)?
Răspuns
(C)
1:2:1
3
What does the principle of independent assortment state?
Răspuns
(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?
Răspuns
(B)
Pedigree
5
What is a codon made of?
Răspuns
(C)
3 nucleotides
6
What is the name for the pairing of homologous chromosomes during meiosis?
Răspuns
(A)
Synapsis
7
Which of the following are true regarding genes and alleles?
Răspuns
A
D
8
What is the role of the centromere in a chromosome?
Răspuns
(B)
To hold sister chromatids together.
9
Which of the following is a characteristic of sex-linked traits?
Răspuns
(C)
They are more common in males.
10
What type of inheritance is most likely to affect males more often than females?
Răspuns
(D)
X-linked recessive
11
What are the main events of Meiosis II?
Răspuns
(C)
Separation of sister chromatids
12
What is the expected phenotypic ratio of offspring from a monohybrid cross (Bb x Bb) with complete dominance?
Răspuns
(B)
3:1
13
What is a monohybrid cross?
Răspuns
(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?
Răspuns
A
D
15
Which of the following would be the correct genotype for a female carrier of an X-linked recessive trait?
Răspuns
(D)
XBXb
16
What does the term "carrier" refer to in genetics?
Răspuns
(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?
Răspuns
(A)
A shaded shape indicates that the individual has the trait.
18
What does a recessive allele require to express its phenotype?
Răspuns
(B)
Two copies of the same allele.
19
What is the relationship between genes and chromosomes?
Răspuns
A
C
D
20
In a pedigree, what shape is used to represent a male?
Răspuns
(B)
Square
21
What is the process of forming a protein from a mRNA sequence called?
Răspuns
(B)
Translation
22
What is the difference between mitosis and meiosis?
Răspuns
(B)
Mitosis produces genetically identical cells while meiosis produces genetically different cells.
23
What are the products of transcription?
Răspuns
(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?
Răspuns
(D)
4:0
25
If a plant has a genotype of Tt for plant height, what is its phenotype?
Răspuns
(A)
Tall
26
Which of the following inheritance patterns involves genes located on the sex chromosomes?
Răspuns
(B)
X-linked inheritance
27
What is a karyotype?
Răspuns
(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)
Răspuns
A
D
29
Which of the following is NOT a base found in DNA?
Răspuns
(D)
Uracil
30
Which of the following processes is involved in asexual reproduction? (Select all that apply)
Răspuns
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)?
Răspuns
(C)
50%
32
What is the role of spindle fibers?
Răspuns
(C)
To separate chromosomes
33
What is the process that produces gametes?
Răspuns
(B)
Meiosis
34
What type of inheritance is exemplified by the ABO blood group system?
Răspuns
(C)
Codominance
35
What is the phenotypic ratio expected from a cross between two heterozygous individuals (Aa x Aa)?
Răspuns
(B)
3:1
36
What is the process in which mRNA is created?
Răspuns
(A)
Transcription
37
If a trait is autosomal recessive, what is the expected phenotype of an individual with the genotype Aa?
Răspuns
(A)
The dominant phenotype.
38
What is the function of the spindle fibers during cell division?
Răspuns
(B)
To separate sister chromatids.
39
Which of the following statements correctly describes the relationship between DNA, genes, and proteins? (Select all that apply)
Răspuns
A
B
D
40
What is the genotype for an individual that is heterozygous for two traits? (e.g., seed shape and seed color)
Răspuns
(B)
AaBb
41
What is the function of a gene?
Răspuns
(B)
To code for a specific protein.
42
Which of the following is a difference between mitosis and meiosis?
Răspuns
(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?
Răspuns
(B)
25%
44
Which of the following is an example of codominance?
Răspuns
(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?
Răspuns
(C)
50%
46
If two heterozygous individuals are crossed (e.g., Gg x Gg), what proportion of the offspring will show the recessive phenotype?
Răspuns
(B)
25%
47
During which phase of mitosis do the sister chromatids separate?
Răspuns
(C)
Anaphase
48
Which of the following statements about DNA is correct?
Răspuns
(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)?
