Biology for IGCSE & O level - Inheritance (Section 6)
1
Which of the following processes is directly responsible for creating genetic variation?
Răspuns
(D)
Crossing over during meiosis
2
What is the role of a promoter region in a gene?
Răspuns
(B)
To signal the start of transcription.
3
Which of the following is the correct order of events in protein synthesis?
Răspuns
(B)
Transcription, Translation, Replication
4
What is the expected phenotypic ratio in a monohybrid cross if the alleles show incomplete dominance?
Răspuns
(B)
1:2:1
5
Which of the following contribute to genetic variation?
Răspuns
A
B
C
6
What are the products of meiosis II?
Răspuns
(D)
Four haploid cells
7
What is the term that refers to different forms of a gene?
Răspuns
(B)
Allele
8
How many chromosomes are typically found in a human somatic (body) cell?
Răspuns
(B)
46
9
What information can be derived from a pedigree chart?
Răspuns
A
B
C
10
Which of the following statements is TRUE regarding the products of meiosis?
Răspuns
(C)
The resulting cells are haploid.
11
Which process results in the separation of homologous chromosomes?
Răspuns
(B)
Meiosis I
12
During which phase of mitosis does the nuclear envelope reform?
Răspuns
(D)
Telophase
13
Which of the following statements is true regarding the inheritance of autosomal dominant disorders?
Răspuns
A
B
D
14
Which of the following is an example of a human trait determined by multiple alleles?
Răspuns
(A)
Blood type (ABO)
15
What is the significance of the F1 generation in Mendelian genetics?
Răspuns
(B)
It is the result of crossing the P generation.
16
If two genes are located very close together on the same chromosome, what is more likely to happen?
Răspuns
(C)
Genetic linkage
17
What is the relationship between genotype and phenotype?
Răspuns
(A)
The genotype determines the phenotype.
18
Which of the following is the primary goal of meiosis?
Răspuns
(C)
Production of gametes.
19
In a situation of incomplete dominance, what is the phenotype of a heterozygote?
Răspuns
(C)
It is a blend of the two parental phenotypes.
20
Which of the following are directly involved in protein synthesis?
Răspuns
A
B
C
21
Which process involves the synthesis of an RNA molecule from a DNA template?
Răspuns
(C)
Transcription
22
Which type of inheritance is characterized by the interaction between two or more genes to control a single phenotype?
Răspuns
(B)
Epistasis
23
Which of the following is true about meiosis II?
Răspuns
(C)
Sister chromatids separate.
24
In a pedigree, what does a filled-in (shaded) symbol represent?
Răspuns
(C)
An individual expressing the trait
25
What is the name of the process where a strand of DNA is used to make a complementary RNA molecule?
Răspuns
(B)
Transcription
26
Which of the following are events in Meiosis I?
Răspuns
A
C
D
27
What is the role of a ribosome in protein synthesis?
Răspuns
(C)
To read the mRNA code and assemble amino acids into a protein.
28
Which processes are involved in sexual reproduction?
Răspuns
A
B
29
What is the significance of crossing over in meiosis?
Răspuns
(B)
It increases genetic diversity.
30
If two genes are linked, what does that mean?
Răspuns
(B)
They are on the same chromosome.
31
What is the purpose of the start codon in translation?
Răspuns
(B)
To initiate protein synthesis.
32
What is the diploid number for human cells?
Răspuns
(B)
46
33
If a woman is a carrier for an X-linked recessive trait, and her husband does NOT have the trait, what is the probability their daughter will also be a carrier?
Răspuns
(C)
50%
34
If a trait is autosomal dominant, what must the genotype of an affected individual be?
Răspuns
(D)
Aa or AA
35
What is the function of the anticodon?
Răspuns
(A)
To bind to the mRNA codon.
36
What is the primary outcome of meiosis?
Răspuns
(B)
Production of haploid gametes.
37
Which of the following is an example of incomplete dominance?
Răspuns
(B)
Flower color in snapdragons (red x white = pink).
38
What are the possible phenotypes resulting from a cross between a homozygous dominant and a heterozygous individual, assuming complete dominance?
Răspuns
(A)
Only the dominant phenotype.
39
What does the term 'homozygous recessive' mean?
Răspuns
(C)
Having two identical recessive alleles for a gene.
40
What is the role of the cell plate in plant cell cytokinesis?
Răspuns
(A)
To form a new cell wall.
41
During which phase of meiosis does synapsis (pairing of homologous chromosomes) occur?
Răspuns
(A)
Prophase I
42
In incomplete dominance, what will be the phenotypic ratio of offspring from a cross between two heterozygous individuals?
Răspuns
(C)
1:2:1
43
What process is represented by the phrase "DNA unwinds and forms a long thread"?
Răspuns
(D)
Decondensation
44
Which type of cell division produces genetically different cells?
Răspuns
(C)
Meiosis
45
What is the difference between mitosis and meiosis?
Răspuns
(C)
Mitosis produces genetically identical cells; meiosis produces genetically different cells.
46
What is the relationship between genes, DNA, and chromosomes?
Răspuns
(B)
Chromosomes are made of genes, which are made of DNA.
47
Which of the following are events that occur during translation? (Select all that apply)
Răspuns
A
B
D
48
In a situation where codominance is present, what will happen to the phenotype?
Răspuns
(D)
Both alleles are equally expressed in the phenotype.
49
Which of the following is an example of a phenotype?
Răspuns
(C)
An organism's observable traits.
50
During what phase of mitosis do the chromosomes line up in the middle of the cell?
