Dear Students,
Welcome to Developmental Biology MCQ – 02 (Developmental Biology for CSIR NET). This MCQ set consists of Advanced (PG Level) Developmental Biology / Embryology Multiple Choice Questions with Answer Key. All these questions were taken from the previous year question papers of CSIR JRF NET Life Sciences Examination. These questions can be used for the preparation of Competitive examinations in Biology / Life Sciences such as CSIR JRF NET, ICMR JRF, DBT BET JRF, GATE and other University Ph.D Entrance Examinations.
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(1). Instructive and permissive interactions are two major modes of inductive interaction during development. The following compares some properties of cell lines and cord blood stem cells. Cell lines, which are stored in liquid nitrogen, can be retrieved for experiments, where they behave as per their original self. Cord blood can also be retrieved from liquid nitrogen for procuring stem cells. Unlike cell lines, the stem cells can be additionally induced to undergo differentiation into desired lineages, which are very different from their original self. The behaviour of cell lines and stem cells is analogous to which of the interactions?
(a). Both cell lines and stem cells show instructive interaction
(b). Cell lines show instructive interaction whereas stem cells show permissive interaction
(c). Cell lines show permissive interaction whereas stem cells show instructive interaction
(d). Both types of cells show permissive instruction
Ans. (c)
(2). Following are certain statements regarding morphogen gradients and cell specification.
(A). Morphogens are always transcription factors
(B). Morphogens can be paracrine factors that are produced in one group of cells and travel to another population of cells
(C). When the concentration of a morphogen drops below a certain threshold, cells stop differentiating and never get determined to another fate
(D). Morphogen gradients are involved in conditional specification
Which combination of the above statements is true?
(a). (A) and (B)
(b). (B) and (D)
(c). (C) and (D)
(d). (A) and (C)
Ans. (b)
(3). Successful fertilization in sea urchin demands specific interaction between proteins and receptors of sperms and eggs. In view of the above, which one of the following combinations is correct?
(a). Bindin in acrosomes and bindin receptors on egg vitelline membrane
(b). Bindin in egg membrane and bindin receptors in acrosomes
(c). Resact on egg jelly and bindin on sperm membrane
(d). Proteasomes on egg membranes and complex sugars on sperm membranes
Ans. (a)
(4). Following statements are made in relation to the five widely recognized stages of Arabidopsis embryogenesis:
(A). The fusion of haploid egg and sperm takes place in Globular stage
(B). Rapid cell division in two regions on either side of the future shoot apex forms Heart stage
(C). The cell elongation throughout the embryo axis and further development result in Torpedo stage
(D). The embryo loses water and becomes metabolically inactive in the Zygotic stage
Which combination of the above statements is correct?
(a). (A) and (B)
(b). (B) and (C)
(c). (C) and (D)
(d). (D) and (A)
Ans. (b)
(5). Following are the events that might take place during dorso-ventral axis specification in early embryonic development of Drosophila:
(A). ‘Torpedo’ receptor activation
(B). ‘Pipe’ synthesis
(C). A cascade of protease activity
(D). ‘Cactus’ dephosphorylation
(E). Entry of ‘Dorsal’ in the nuclei of syncytial blastoderm stage embryo.
Which combination of the above events will occur in the presumptive dorsal side of the embryo deficient in maternal gurken?
(a). A only
(b). B and C only
(c). B, C and E only
(d). B, C, D and E only
Ans. (c)
(6). A specific Mitogen Activated Protein Kinase (MAPK) cascade comprising MEKK1(a MAP3K), MKK1 (a MAP2K) and MPK6 (a MAPK) is activated sequentially in that order in Arabidopsis plants upon perceiving certain abiotic stress stimuli. The activated MPK6 phosphorylates and activates a transcription factor ‘X’, thereby making plant tolerant to the abiotic stress. Two different variants of MKK1 protein, a kinase inactive (KI) and a constitutively active (CA) forms were expressed independently in mkk1 mutant Arabidopsis plant. Considering above facts, which one of the following statements is CORRECT?
(a). ‘X’ will be activated even in the absence of stimuli in CA plants
(b). ‘X’ will not be activated in the absence of stimuli in CA plants
(c). ‘X’ will be activated in the absence of stimuli in KI plants
(d). The KI plants will be tolerant to the abiotic stress.
Ans. (a)
(7). During lens formation in the Xenopus, the following statements have been proposed:
(A). Lens induction can be achieved in the absence of optic vesicle after priming of head ectoderm by the anterior neural plate
(B) The optic vesicle can induce the presumptive trunk ectoderm to form the lens
(C). Only the head ectoderm can respond to direct signals from the optic vesicle to form the lens
(D). The anterior neural plate primes the head ectoderm via BMP4 and Fgf8 prior to signals from the optic vesicle.
Which of the above combinations is correct?
(a). (C) and (D)
(b). (B) and (D)
(c). (A) and (D)
(d). (A) and (C)
Ans. (c)
(8). Mutation in a gene x in Arabidopsis thaliana results in more number of lateral root formation. Which one of the following is the correct statement?
(a). The gene product acts as a positive regulator of lateral root formation
(b). The gene product acts as a negative regulator of lateral root formation’
(c). The gene product is not likely to be involved in lateral root formation
(d). The gene product promotes replication for lateral root development
Ans. (b)
(9). Migration of individual cells from the surface into the embryo’s interior is termed as:
(a). Ingression
(b). Involution
(c). Invagination
(d). Delamination
Ans. (a)
(10). Floral organ development is controlled by overlapping expression of ‘A’ class, ‘B’ class and ‘C’ class genes in different whorls. In an Arabidopsis mutant, the flowers had sepals, sepals, carpels and carpels in the four whorls. Mutation in which one of the following is the cause for the mutant phenotype?
(a). ‘A’ class gene alone
(b). ‘B’ class gene alone
(c). ‘A’ and ‘B’ class genes
(d). ‘C’ class gene alone
Ans. (b)