MCQ ON GENETICS- PART 4

MCQ ON GENETICS- PART 4

• A cross between two true breeding lines one with dark green flowers and one with bright white flowers produces F1 offspring that are light green. When the F1 progeny are selfed a 1:2:1 ratio of dark green to light green to white flowers is observed. What genetic phenomenon is consistent with these results?

1. Epistasis
2. Incomplete dominance
3. Codominance
4. Inbreeding depression
5. Random mating

• Mutations which occur in body cells which do not go on to form gametes can be classified as:

1. Auxotrophic mutations
2. Somatic mutations
3. Morphological mutations
4. Oncogenes
5. Temperature sensitive mutations

• Mendel developed his basic principles of heredity by

1. Microscopic study of chromosomes and genes
2. Mathematical analysis of the offspring of Pea plant
3. Breeding experiments with Drosophila
4. Anatomical studies of Pea plant
5. Physiological study of pea plant

Read also… MENDEL’S LAW OF INHERITANCE

• What would be the frequency of AABBCC individuals from a mating of two AaBbCc individuals?

1. 1/64
2. 1/32
3. 1/16
4. 1/8
5. 3/16

• How many different genotypes are possible from a cross between the parents RR and rr

1. Four
2. One
3. Three
4. Two
5. Five

• When two hybrids are crossed, the percentage of recessive is

1. 25%
2. 100%
3. 50%
4. 75%
5. 150%

• Which Mendelian cross can produce two genotypes and two phenotypes?

1. Monohybrid cross
2. Monohybrid test cross
3. Incomplete dominance
4. Co-dominance
5. Both A & B

• The stage of meiosis in which chromosomes pair and cross over takes place:

1. Prophase I
2. Metaphase
3. Prophase II
4. Metaphase II
5. Anaphase II

See… MITOSIS & MEIOSIS- CELL DIVISION

• The main event that occur during pachytene are:

1. Formation of bivalent
2. Crossing over
3. Only A
4. Both A & B
5. None of these

• Which of the statements given below is correct with respect to frameshift mutation

1. a single nucleotide base change, insertion, or deletion of the genetic material
2. Glutamine is replaced by valine
3. Sickle cell anemia is an example
4. Insertions or deletions of a number of nucleotides in a DNA sequence that is not divisible by three.

• Polyploidy refers to:

1. Extra copies of a gene adjacent to each other on a chromosome
2. An individual with complete extra sets of chromosomes
3. A chromosome which has replicated but not divided
4. Multiple ribosomes present on a single mRNA
5. An inversion which does not include the centromere

See… TYPES OF CHROMOSOME-STRUCTURE&DEFINITION

• Presence of more than two genomes in an individual is known as:

1. Monoploid
2. Polyploidy
3. Haploid
4. Both A & C
5. None of these

• Polyploidy is mainly induced treatment with a chemical known as:

1. Phosphatase
2. Colchicine
3. Ligase
4. Mercuric chloride
5. None of above

• A gene showing codominance:

1. has both alleles independently expressed in the heterozygote
2. has one allele dominant to the other
3. has alleles tightly linked on the same chromosome
4. has alleles expressed at the same time in development
5. has alleles that are recessive to each other

• Round seed is dominant over wrinkled seeds in Pea. If homozygous, round seeded Pea plants are crossed with wrinkled seeded plants, the offsprings will be

1. All round
2. All wrinkled
3. 75% round and 25% wrinkled
4. 50% round and 50% wrinkled
5. Cannot be determined.

• Which of the following disorder shows Criss cross inheritance?

1. Haemophilia
2. Colour blindness
3. Erythroblastosis foetalis
4. (a) & (b)
5. None of the above

• The phenomenon of “independent assortment” refers to:

1. Expression at the same stage of development
2. Unlinked transmission of genes in crosses resulting from being located on different chromosomes, or far apart on the same chromosome
3. Association of an RNA and a protein implying related function
4. Independent location of genes from each other in an interphase cell
5. Association of a protein and a DNA sequence implying related function

• Mendel’s law of segregation, as applied to the behavior of chromosomes in meiosis, means that:

1. Pairing of homologs will convert one allele into the other, leading to separation of the types.
2. Alleles of a gene separate from each other when homologs separate in meiosis I, or in meiosis II if there is a single crossover between the gene and the centromere.
3. Genes on the same chromosome will show 50% recombination
4. Alleles of a gene will be linked and passed on together through meiosis

• If heterozygous round seeded pea plants are self-pollinated, the offspring will be

1. 75% round
2. 50% heterozygous
3. 25% rr
4. 100% round
5. A, B & C

• Which component of transcribed RNA in eukaryotes is present in the initial transcript but is removed before translation occurs:

1. Intron
2. 3’ Poly A tail
3. Ribosome binding site
4. 5’ cap
5. codons coding for the protein to be produced

• In a nucleotide, the nitrogen base is joined to the sugar molecule by

1. Phosphodiester bond
2. Glycosidic bond
3. Hydrogen bond
4. (A) &(B)

• Choose the correct statement about the genetic code

1. Includes 61 codons for amino acids and 3 stop codons
2. Almost universal; exactly the same in most genetic systems
3. Three bases per codon
4. Some amino acids are coded by multiple codons
5. All of the above

• X-chromosome inactivation:

1. Normally takes place in males but not females
2. is the cause of the Y chromosome being genetically inactive
3. takes place in humans so that the same X chromosome is inactive in all of the cells of a female
4. occurs in fruit flies but not in mammals
5. results in genetically turning off one of the two X chromosomes in female mammals

• DNA ligase refers to:

1. An enzyme that joins fragments in normal DNA replication
2. An enzyme involved in protein synthesis
3. An enzyme of bacterial origin which cuts DNA at defined base sequences
4. An enzyme that facilitates transcription of specific genes
5. An enzyme which limits the level to which a particular nutrient reaches

• An Hfr strain of E. coli contains:

1. Vector of yeast or bacterial origin which is used to make many copies of a particular DNA sequence
2. A bacterial chromosome with a human gene inserted
3. A bacterial chromosome with the F factor inserted
4. A human chromosome with a transposable element inserted
5. A bacterial chromosome with a phage inserted

• Which of the following is the most likely explanation for a high rate of crossing-over between two genes?

1. The two genes are far apart on the same chromosome.
2. The two genes are both located near the centromere.
3. The two genes are sex-linked.
4. The two genes code for the same protein.
5. The two genes are on different chromosomes.

• Generation of antibody diversity in vertebrate animals takes place through:

1. The presence of as many genes in the germ line as there are types of antibodies possible
2. Infection with bacteria carrying antibody genes
3. Infection with viruses carrying antibody genes
4. Polyploidy in antibody-forming cells
5. Rearrangement of DNA in tissues that go on to produce antibodies

• Replication of DNA:

1. Takes place in a “conservative” manner
2. Takes place in a “dispersive” manner
3. Takes place in a “semi-conservative” manner
4. Usually involves one origin of replication per chromosome in eukaryotes
5. Takes place only in the 3’ to 5’ direction

See… DNA REPLICATION-DEFINITION & PROCESS

• A duplication is:

1. An exchange between non-homologous chromosomes, resulting in chromosomes with new genes adjacent to each other.
2. loss of genes in part of a chromosome
3. An extra copy of the genes on part of a chromosome
4. A reversal of order of genes on a chromosome
5. An extra set of chromosomes in an organism

• A mutation in a codon leads to the substitution of one amino acid with another. This type of mutation is called?

1. Nonsense mutation
2. Missense mutation
3. Frameshift mutation
4. Promoter mutation
5. Operator mutation

Read… WHAT IS MUTATION- AN OVERVIEW & TYPES

• Mapping of human chromosomes:

1. has been restricted to the sex chromosomes because of small family sizes
2. proceeded much more successfully as large numbers of DNA markers became available
3. has determined that the number of linkage groups is about twice the number of chromosomes
4. has demonstrated that almost all of the DNA is involved in coding for genes
5. has shown that there are more genes on the Y than on the X chromosome

• A sexual unit:

1. Gamete
2. Gene
3. Allele
4. Hybrid
5. None of the above

• The plant in which Hugo de Vries introduces the concept of mutation is

1. Oenothera lamarkiana
2. Pisum sativum
3. Allium cepa
4. Mirabilis jalapa
5. Argemone Mexicana

• Eyes that slant upwards with epicanthus is a characteristic of

1. Klinefelter’s syndrome
2. Turner’s syndrome
3. Down’s syndrome
4. Super female
5. pleiotropy

• Homeobox sequences:

1. are present in the genome of many animals’ species
2. are found in prokaryotes but not in eukaryotes
3. were identified as the integration sites for bacterial viruses
4. represent integration sites for transposable elements
5. represent the termination signals for transcription

• Tracing of a cell lineage during development means that:

1. the cells giving rise to and derived from a specific cell are known
2. the sequence of the enhancers for developmental genes is known
3. the regulatory genes for the organism have been genetically mapped
4. Cell components in the membrane involved in signaling have been isolated
5. Cell components in the nucleus involved in signaling have been isolated

• Zinc finger proteins and helix-turn-helix proteins are:

1. types of DNA-binding proteins
2. involved in the control of translation
3. components of ribosomes
4. part of the hemoglobin in blood cells
5. bound to transfer RNA during replication

• Transcriptional activator proteins:

1. transcribe a messenger off a DNA template
2. bind to ribosomes to activate the production of specific proteins
3. are produced during an infection of bacteria by a phage
4. are essential to function of transfer RNAs during translation
5. bind regions near a eukaryotic gene and allow an RNA polymerase to transcribe a gene

• The process of synthesis of messenger RNA from a DNA template is known as:

1. Transcription
2. Transduction
3. Translation
4. Duplication
5. All of these

• Enzyme which can break and seal the DNA strand:

1. Topoisomerase II
2. Helicase
3. Primase
4. Restriction endonuclease
5. Urease

• Cinderella of Genetics is:

1. Pisum sativum
2. Snapdragon
3. Oenothera
4. Drosophila
5. Honey bee

• Differential distribution of substances in the egg most typically results in:

1. differences in gene expression which may establish a pattern in the embryo as the cells divide
2. amplification of specific genes during development
3. development of polyploid tissues
4. loss of specific genes during development
5. dominance of genes derived from the father

• Arabidopsis is advantageous for plant genetic research because:

1. It is commercially important as a food crop
2. it is an endangered species
3. it is the closest to humans of any existing plant
4. it is a small plant with a small genome size which can be raised inexpensively
5. it is a close relative of corn and results with this species can be applied to problems in corn

• A homeotic mutation is one which:

1. is present in only one form in an individual
2. substitutes one body part for another in development
3. results in development of a tumor
4. is wild type at one temperature and abnormal at another
5. leads to increased body size in an organism

• Assuming that the level of glucose is low, a mutation in the repressor of the lac operon in E. coli, preventing binding of the repressor to the operator, should result in:

1. Constitutive expression of the lac operon genes
2. lack of expression or reduced expression of the lac operon genes under all circumstances
3. expression of the genes only when lactose is present
4. expression of the genes only when lactose is absent

• Assuming that the level of glucose is low, a mutation in the repressor associated with the lac operon of E. coli which prevents binding of the repressor to lactose should result in:

1. Constitutive expression of the lac operon genes
2. lack of expression or reduced expression of the lac operon genes under all circumstances
3. expression of the genes only when lactose is present
4. expression of the genes only when lactose is absent

• RFLP analysis is a technique that

1. uses hybridization to detect specific DNA restriction fragments in genomic DNA
2. is used to determine whether a gene is transcribed in specific cells
3. measures the transfer frequency of genes during conjugation
4. is used to detect genetic variation at the protein level
5. is used to amplify genes for producing useful products

• RFLP stands for:

1. Restriction fragment length polyploidy
2. Restriction fragment length polymorphisms
3. Restriction fragment less polymorphisms
4. Both A & B

• Skin colour is controlled by

1. Pleiotropic genes
2. Dominant genes
3. Polygenes
4. Recessive gene

• Some characters expressed by factors present in the cytoplasm, such factors are called:

1. Multiple allele
2. Plasma genes
3. Pseudogenes
4. Mutagens
5. Both C & D

See also…
MCQ ON GENETICS- PART 3
MCQ ON GENETICS- PART 2
MCQ ON GENETICS & PLANT BREEDING- PART1