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Biology for IGCSE & O level - Inheritance (Section 1)

1
What is the key difference between autosomal and sex-linked traits?
Answer
(C)
Autosomal traits are located on autosomes; sex-linked traits are located on sex chromosomes.
2
In what part of the cell does translation take place?
Answer
(B)
Ribosomes
3
Which of the following is a characteristic of cancer cells?
Answer
(B)
Uncontrolled cell division.
4
Which organelle is directly involved in protein synthesis?
Answer
(C)
Ribosome
5
What are the key functions of enzymes?
Answer
A
C
6
What is a codon?
Answer
(B)
A three-base sequence of mRNA that codes for an amino acid.
7
What is the role of the centromere?
Answer
(B)
To hold sister chromatids together.
8
In autosomal dominant inheritance, what is the probability of an affected parent with the genotype Aa having an affected child?
Answer
(C)
50%
9
What term is used to describe a gene that has multiple alleles?
Answer
(B)
Multiple allelic
10
Which of the following is a characteristic of a recessive allele?
Answer
(B)
It is only expressed when homozygous.
11
What is the role of meiosis in the context of genetics?
Answer
(A)
Produces gametes.
12
Which of the following is true regarding an individual's genes?
Answer
(D)
All of the above.
13
How many alleles does a single gene typically have?
Answer
(D)
Multiple
14
What is the function of spindle fibers in mitosis?
Answer
(B)
To separate the chromosomes.
15
Which of these are part of a DNA molecule?
Answer
A
C
D
16
What type of cell division results in four genetically different haploid cells?
Answer
(C)
Meiosis
17
In what part of the cell does transcription take place?
Answer
(C)
Nucleus
18
Which of the following are key aspects of the genetic code?
Answer
A
B
D
19
Which of the following is an accurate statement regarding autosomal recessive inheritance?
Answer
(B)
Affected individuals are always homozygous for the recessive allele.
20
Which of the following is an example of a mutagen?
Answer
(B)
Sunlight
21
Which of the following are features of a gene?
Answer
A
B
C
22
What are the main reasons for genetic variation?
Answer
A
B
C
23
What is a 'dihybrid cross'?
Answer
(B)
A cross involving two traits.
24
Which of the following events does NOT occur during telophase of mitosis?
Answer
(D)
The sister chromatids separate.
25
Which of the following are key features of a gene?
Answer
A
B
D
26
Which of the following is a function of DNA?
Answer
(A)
To carry genetic information.
27
What would be the phenotypic ratio of a cross between two heterozygous individuals (Aa) if the alleles exhibited complete dominance?
Answer
(B)
3:1
28
Which of the following is an example of a trait that is likely influenced by multiple genes?
Answer
(B)
Eye color
29
What is the purpose of the 'test cross' in genetics?
Answer
(B)
To determine if an individual is homozygous dominant or heterozygous for a trait.
30
What is the sequence of the bases on mRNA to represent the sequence of amino acids Glycine, Alanine, Serine?
Answer
(C)
CCA-GCG-AGC
31
What are the possible genotypes for a person with blood type A in the ABO blood group system?
Answer
A
C
32
What type of inheritance is exhibited when both alleles are equally expressed in the heterozygous condition, resulting in a combined phenotype?
Answer
(C)
Codominance
33
What is the role of mRNA in protein synthesis?
Answer
(B)
To carry the genetic code from the nucleus to the ribosome.
34
What type of molecule is responsible for carrying the genetic code from the nucleus to the ribosomes?
Answer
(C)
mRNA
35
Which of the following statements are true about a carrier of a recessive genetic disorder?
Answer
B
C
36
What does the term "homozygous recessive" mean?
Answer
(C)
Having two identical recessive alleles.
37
What is the primary function of tRNA?
Answer
(B)
To bring amino acids to the ribosome.
38
What is the process of copying a DNA molecule to produce two identical DNA molecules called?
Answer
(C)
Replication
39
What are the key differences between mitosis and meiosis in terms of cells produced?
Answer
A
B
C
D
40
Which of the following processes occurs during prophase of mitosis?
Answer
(C)
The nuclear envelope breaks down.
41
Which of the following events contribute to genetic variation during meiosis?
Answer
A
B
42
Which of the following processes is a source of genetic variation during meiosis?
Answer
(C)
Crossing over
43
Which of the following are key processes that lead to genetic variation?
Answer
A
B
44
Which of the following are examples of proteins?
Answer
A
B
D
45
What is the term used to describe the mating of two organisms that have different genetic characteristics?
Answer
(A)
Hybridization
46
Which of the following are differences between mitosis and meiosis?
Answer
A
C
47
If a couple is both carriers for an autosomal recessive disorder, what is the probability that their child will have the disorder?
Answer
(B)
25%
48
What is the term used to describe an individual who has two different alleles for a particular gene?
Answer
(B)
Heterozygous
49
In Mendel's experiments, what is the term for the offspring resulting from the cross of the F1 generation?
Answer
(C)
F2 generation
50
How many chromosomes are present in a normal human sperm cell?
Answer
(A)
23