Category: CSIR NET Life Science Previous Year Questions and Solution on Morphogenesis and Organogenesis in Plants

Category: CSIR NET Life Science Previous Year Questions and Solution on Morphogenesis and Organogenesis in Plants

CSIR NET Life Science Previous Year Questions and Solution on Morphogenesis and Organogenesis in Plants

73. Both TGF β and Sonic hedgehog signals play important roles in both neurulation and cell-fate patterning of the neural tube. Which one of the following statements is true? (1) High levels of BMP specify the cells to become epidermis. (2) Very low levels of BMP specify the cells to become epidermis. (3) High levels of BMP specify the cells to become neural plate. (4) Intermediate levels of BMP do not effect the formation of neural crest cells.

Role of BMP Signaling in Neural Plate and Epidermis Specification During Neural Tube Formation

59. Morphylaxis can be defined as (1) Production of lost organ by division in remaining cell (2) Re-initiation of cell division in existing cells, followed by re-patterning of those cells (3) Production of complete organism by single cell (4) Movement of organism toward stimulus

Definition of Morphallaxis: Regeneration by Reorganization of Existing Cells

46. Which one of the following statements regarding limb regeneration in Salamander is correct? (1) A normal limb is regenerated after amputation, irrespective of whether the cut was made below the elbow or through the humerus. (2) It occurs by compensatory regeneration and does not include formation of an apical ectodermal cap. (3) Regeneration occurs through formation of a blastema, which essentially consists of unspecified multi-potential progenitor cells. (4) Proliferation of the blastema cells does not require nerves or factors secreted by the nerves.

Mechanism of Limb Regeneration in Salamanders: Role of Blastema and Positional Specification

45. How will the regeneration of a newt limb be affected if the nerve supply is severed before amputation? (1) Partial regeneration will occur where only the proximal structures will be formed. (2) Regeneration of most of tissues of the limb occurs normally but the regeneration of the nerve will fail. (3) Regeneration will occur but the identity of the limb is lost and normal proximal-distal patterning will not occur. (4) blastema will form but not grow and regeneration will fail.

Effect of Severing Nerve Supply on Newt Limb Regeneration: Importance of Nerves for Blastema Growth and Limb Outgrowth

44. What would be the effect on newt limb regeneration, if more than 90% of the nerve supply is severed before amputation? (1) The apical ectodermal cap stimulates growth of the blastema by secreting FGF8 but regeneration does not take place. (2) Limb regeneration will take place and form a limb with no nerve supply. (3) Outgrowth will occur but the identity of the limb formed will be lost with no clear anterior-posterior polarity. (4) Limb regeneration with nerve supply will take place.

Effect of Severe Nerve Severance on Newt Limb Regeneration: Role of Nerve Supply and Growth Factors

69. The flowering repressor gene that is responsible for the vernalization requirement in Arabidopsis is: (1) CONSTANS (CO) (2) FLOWERING LOCUS D (FD) (3) FLOWERING LOCUS T (FT) (4) FLOWERING LOCUS C (FLC)

FLOWERING LOCUS C (FLC): The Key Repressor Gene Responsible for Vernalization Requirement in Arabidopsis

Given below are the list of proteins (Column X) and their functions (Column Y) during floral induction. Which one of the following options represents the correct match between column X and column Y? (1) A - i, B - ii, C - iii, D - iv (2) A - iii, B - iv, C - i, D – ii (3) A - ii, B - i, C - iv, D – iii (4)A - iv, B - iii, C - ii, D – i 

Key Proteins and Their Functions in Floral Induction: Correct Matching in Arabidopsis thaliana

In most angiosperms, flowers have a perianth that consists of whorls of organs. Select the statement that is INCORRECT about the floral organs in angiosperms. (1) All petals are not homologous (2) If there is only one whorl of organs, these structures are referred to as tepals (3) Sepals tend to be initiated almost simultaneously and never in a spiral sequence. (4) Both sepals and petals can act as protective organs for inner floral organs and also as organs to attract pollinators 

Understanding Floral Organ Development in Angiosperms: Correcting Common Misconceptions

66. Which one of the following options related to plant growth and development is matched correctly? (1) LEAFY: regulator of genomic imprinting (2) Xylogenesis: wood formation (3) FLOWERING LOCUS T (FT) (4) FLOWERING LOCUS C (FLC)

Understanding Xylogenesis: The Process of Wood Formation in Plants

65. AP1 (APETLA 1) is one of the floral meristem identifying genes. In wild type Arabidopsis thaliana plants transformed with AP1:GUS, β glucuronidase (GUS) activity is seen in floral meristem, only after the commitment to flowering. Ectopic expression of AP1::GUS in the EMBRYONIC FLOWER (emf) mutant background results in GUS activity throughout the shoots in four day old seedlings. These observations suggest that AP1 is: - (1) not involved in flowering (2) involved in repression of flowering. (3) involved in promoting flowering. (4) stimulation of flowering in the emf background 

the Role of APETALA1 (AP1) in Promoting Flowering and Floral Meristem Identity in Arabidopsis

Flowers represent a complex array of functionally specialized structures that differ substantially from the vegetative plant body in form and cell types. Following are statements made regarding floral meristems. A. Floral meristems can usually be distinguished from vegetative meristems by their larger size. B. The increase in the size of the meristem is largely a result of increased rate of cell division in central cells. C. The increase in the size of the meristem is due to larger size of the cells, which in turn results from rapid cell expansion only. D. A network of genes control floral morphogenesis in plants. Which combination of the above statements is true? (1) A, B and D (2) A, Band C (3) B, C and D (4) A, C and D 

Genetic and Cellular Control of Floral Meristem Development and Morphogenesis in Plants

63. Which one of the following statements about LEAFY (LFY), a regulatory gene in Arabidopsis thaliana, is correct? (1) LEAFY (LFY) is involved in floral meristem identity (2) LEAFY (LFY) is involved in leaf expansion. (3) LEAFY (LFY) 'is involved in root meristem identity. (4) LEAFY (LFY) is responsible far far-red light mediated seedling growth 

LEAFY (LFY) as a Master Regulator of Floral Meristem Identity in Arabidopsis thaliana

The control of flowering is a complex process involving several key regulatory genes. Some statements on flower development are given below: A. Two major types of genes regulate floral development: meristem identity genes and floral organ identity genes. B. The important genes in Arabidopsis that play key regulatory roles in meristem identity are: APETALA1, LEAFY and SUPPRESSOR OF CONSTANS1. C. The genes that determine floral organ identity were discovered as floral homeotic mutants. D. Most plant homeotic genes belong to a class of related sequences known as FAD box genes. Which one of the following combinations of the above statements is correct? (1) A, B and C (2) B, C and D (3) A, C and D (4) A, B and D 

APETALA2 Gene Expression in Sepal and Petal Development: Verification from the ABC Model of Arabidopsis Flowering

According to the ABC model of floral development in Arabidopsis as shown below Several genes/transcription factors e.g. AP 1, AP2, AP3, AG etc., are involved. Which one of the following statements is correct? (1) Apetala 2 (AP2) transcripts expressed during sepal and petal development. (2) Agamous AG is considered as class A gene. (3) AP1 expressed during carpel development. (4) AP3 expressed during sepal development. 

Expression and Role of APETALA2 in Sepal and Petal Development in Arabidopsis Flower

60. Which one of the following plant homeotic genes does NOT encode MADS- domain transcription factor involved in floral organ specification? (1) AP2                                                         (2) AP1 (3) AP3/P1                                                     (4) AG 

APETALA2: A Non-MADS-Domain Transcription Factor in Floral Organ Specification

Individual and overlapping expression of homoerotic genes in adjacent whorls of a flower determine the pattern of floral organ development. In an Arabidopsis mutant, floral organs are distributed as follows: Whorl 1 (outer most) — carpel Whorl 2 — stamens Whorl 3 – stamens Whorl 4 (inner most) — carpel Loss of function mutation in which one of the following genes would have caused the above pattern of floral organ development? (1) APETALA 2 (2) APETALA 3 (3) PISTILLATA (4) AGAMOUS 

Understanding the Role of AGAMOUS in Floral Organ Development and Mutant Phenotypes in Arabidopsis

58. Following are certain statements regarding the activities of homeotic genes of classes A, B and C involved in floral organ identity: A. Activity of A alone specifies sepals B. Activity of B alone specifies petals C. Activities of B and C form stamens D. Activity of C alone specifies carpels Which one of the following combinations of above statements is correct? (1) A, B and C                                                (2) A, B and D (3) B, C and D                                                (4) A, C and D 

Understanding the ABC Model of Floral Organ Identity: Roles of Class A, B, and C Genes in Arabidopsis

Based on ABC model during flower development, loss of class A activity results in the formation of only stamen and carpel. Which of the following floral organ identity genes controls the class A activity? (1) APETALA 1 and APETALA 2 (2) APETALA 3 and PISTILLATA (3) Only PISTILLATA (4) Only AGAMOUS 

APETALA1 and APETALA2: Key Regulators of Class A Activity in Arabidopsis Floral Organ Development

56. In Agamous mutant (flower within flower phenotype) which of the following statements is valid? (1) Class A genes are expressed in the first two whorls, Class B genes are expressed in the second and third whorls and Class C genes are expressed in the third and fourth whorls. (2) Class A genes are not expressed. Class B and C genes are expressed in all the whorls. (3) Class A genes are not expressed. Class B genes are expressed in the second and the third 

Understanding AGAMOUS Mutant Phenotype and Gene Expression Patterns in Arabidopsis Floral Development

Plants with apetala2 mutation show a phenotype that lacks (1) sepals only. (2) both sepals and petals. (3) petals only. (4) stamens only.

Role of APETALA2 Gene in Sepal and Petal Development in Arabidopsis Flowers

Which of the floral whorls is affected in apetala 3/pistillata (ap3/pi) mutants? (1) Sepals and petals. (2) Petals and stamens. (3) Stamens and carpels. (4) Sepals and stamens. 

Impact of APETALA3/PISTILLATA Mutation on Petal and Stamen Development in Arabidopsis Flowers

Which of the floral whorls is affected in agamous (ag) mutants (1) Sepals and petals (2) Petals and stamens (3) Stamens and carpels (4) Sepals and carpels 

AGAMOUS Gene Function in Floral Organ Development: Impact on Stamens and Carpels

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? (1) 'A' class gene alone (2) 'B' class gene alone (3) 'A' and 'B' class genes (4) 'C' class gene alone 

Impact of B-Class Gene Mutation on Floral Organ Identity in Arabidopsis: The ABC Model Explained

51. Among the following which gene product migrates from leaves to shoot meristem during transition of shoot meristem into floral meristem? (1) Flowering locus T                             (2) Flowering locus D (3) Leafy                                                       (4) Apetala 1

Role of Flowering Locus T (FT) as a Mobile Signal from Leaves to Shoot Apical Meristem in Floral Transition

In plants gene 'sepallata' is NOT involved in formation of organ (1) Sepals (2) Petals (3) Stamens (4) Carpels 

Role of SEPALLATA Genes in Floral Organ Development: Excluding Sepals from SEP Function

Three classed of genes A, B and C regulates the development of flower in Arabidopsis. If a loss-of-function mutation occurs in the B-type genes, what will be the composition of the flower whorls? (1) sepals-petals-stamens-carpels (2) sepals-sepals-stamens-carpels (3) sepals-sepals-carpels-carpels (4) petals-petals-stamens-stamens 

Impact of B-Type Gene Mutation on Flower Whorl Composition in Arabidopsis: Understanding the ABC Model

Organ Identity genes are responsible for correct positioning of floral organs on floral meristem. Mutation in them will lead to (1) Loss of all organs from whorls (2) More number of organs in certain whorls (3) Appearance of organs at incorrect positions (4) No flower 

Role of Organ Identity Genes in Floral Organ Positioning and Development

Light signals for flowering is received by (1) Flower bud (2) Apical bud (3) Leaves (4) Flower bract 

Leaves as Primary Photoreceptors for Flowering Signal Reception in Plants

46. Following are certain statements regarding root growth and differentiation in plants: A. Root hair, endodermis, xylem and phloem reach maturation in elongation zone of a developing root. B. The root epidermal cells that are incapable of forming root hairs are called atrichoblasts. C. Quiescent center is present just above root cap. D. In Arabidopsis, an auxin transporter (ABCB4) plays a role in root hair emergence by maintaining intracellular auxin concentration. Which one of the following combination of statements is correct? (1) A, B and C                                                (2) B, C and D (3) A, C and D                                                (4) A, B and D

Root Growth and Differentiation: Role of Atrichoblasts, Quiescent Center, and ABCB4-Mediated Auxin Transport

Given below are statements related to different aspects of plant growth and development. A. Leaf longevity is increased in ethylene insensitive mutants eir1-1 and ein2 of Arabidopsis. B. Programmed cell death (PCD) is responsible for the formation of prickles, thorns and spines in plants. C. Senescence and PCD occur only in the development of vegetative tissues and does not occur in reproductive tissues D. Re-differentiation of organelles is an integral component during initial stages of senescence in plants. Which one of the following represents the combination of all correct statements? (1) A, C and D (2) B and C (3) A, B and D (4) C and A 

Ethylene Insensitivity, Programmed Cell Death, and Organelle Redifferentiation in Plant Growth and Senescence

Change in leaf morphology is observed during transition from vegetative to reproductive phase in several plants. The following statements are proposed to explain the above observation: A. Alteration in the gene content of leaves of reproductive phase from those of vegetative phase. B. Differential methylation pattern of genes influencing leaf development and morphology. C. Mutation in transcription factor that prevents its association with promoter elements of genes regulating leaf development. D. Small RNA mediated inhibition of gene expression of a homeotic gene. Which one of the following options represents a correct combination of statements that could explain the observed changes? (1) B and C (2) A and D (3) B and D (4) A and C 

Epigenetic and Small RNA Regulation of Leaf Morphology During Vegetative to Reproductive Phase Transition in Plants

43. Given below are factors/terms associated with various aspects of plant growth and development: Which one of the following options represents the most appropriate match between all terms of Column A and Column B? (1) A-ii, B-iii, C-iv, D-l                                       (2) A-iii, B-, C-iv, D-ii (3) A-ii, B-iv, C-, D- iii                                                (4) A-iv, B-i, C-ii, D-iii

Key Factors in Plant Growth and Development: Photosynthesis, Hormones, Nutrition, and Cytoskeletal Dynamics

42. Genetic screens for mutants affecting development of leaf trichomes have led to the discovery of genes regulating trichome patterning - especially trichome density and spacing, as depicted in the figure below.42. Genetic screens for mutants affecting development of leaf trichomes have led to the discovery of genes regulating trichome patterning - especially trichome density and spacing, as depicted in the figure below. The following statements are made in this regard: A. GLABRAI (GLI) mutant plant will show fewer or no trichomes. B. Cells that form trichomes strongly express the GLABRA2 (GL2) and TRYPTICON (TRY) genes. C. TRY protein acts as a positive regulator of trichome cell differentiation in the surrounding cells. D. Addition of exogenous JA will reduce the number of leaf trichomes. Which one of the following options represents the combination of all correct statements? (1) A and B                                                    (2) B and C (3) C and D                                                    (4) A and D

Genetic Regulation of Leaf Trichome Development in Arabidopsis: Roles of GL1, GL2, TRY, and Jasmonic Acid

41. The following diagram represents a longitudinal section through an Arabidopsis shoot apical meristem (SAM) and leaf primordium at its flank. The dorsal (D) and ventral (V) domains are marked. The D and V genes are expressed in the dorsal and ventral domains, respectively Consider the following statements describing the phenotypes of leaf polarity. A. Loss of D function makes the leaf ventralized whereas its overexpression dorsalizes the leaf. B. Loss of V function makes the leaf dorsalized whereas its overexpression ventralizes the leaf. C. Loss of microRNA miR166 dorsalizes the leaf whereas its overexpression ventralizes the leaf. D. miR166 functions by inhibiting its target mRNA. Which one of the following functional models best describes the above results?

Genetic Regulation of Leaf Polarity in Arabidopsis: Roles of D Genes, V Genes, and miR166

Members of the WUSCHEL RELATED HOMEOBOX (WOX) transcription factor family play an important role during zygote elongation and division in Arabidopsis. Following are certain statements regarding the expression of different members of WOX gene family during zygote elongation. (A) WOX2 and WOX8 are present in both the egg cell and the zygote. (B) WOX2 is present in the apical and basal cell. (C) WOX8 along with WOX9 regulates the development of basal lineage. (D) WOX8 and WOX9 are directly activated in the zygote by the transcription factor WRKY2. Which one of the following options represents combination of all correct statements? (1) A, B and C (2) A, B and D (3) A, C and D (4) B, C and D 

Role of WOX Gene Family and WRKY2 in Arabidopsis Zygote Elongation and Early Embryo Patterning

39. Consider the following facts regarding the control of shoot apical meristem (SAM) size in Arabidopsis (a) Loss of the CLAVATA1 (CLV1) gene leads to bigger SAM (b) Loss of the CLAVATA3 (CLV3) gene leads to bigger SAM (c) Loss of the WUSCHEL (WUS) gene leads to smaller SAM (d) Loss of both CLV1 and WUS leads to smaller SAM (e) Loss of both CLV3 and WUS leads to smaller SAM (f) Loss of both CLV1 and CLV3 leads to bigger SAM (g) Over expression of CLV3 leads to smaller SAM (h) Over expression of CLV3 in the loss of function mutant of CLV1 leads to bigger SAM. Based on the above information, which of the following genetic pathways describes the   relationship among CLV1, CLV3 and WUS most appropriately

CLAVATA-WUSCHEL Feedback Regulation in Arabidopsis Shoot Apical Meristem Size Control

38. Extensive molecular genetic studies on miR156, miR172, SPL genes and AP2- like genes have yielded the following functional model on the juvenile → adult → reproductive transition in Arabidopsis Based on these results, the following schematic diagram has been proposed to predict the expression kinetics of these genetic factors: Which of the following combinations is most likely to be correct? (1) a-miR156; b-SPL genes; c -miR172; d - AP2 like genes (2) a-miR156; b-miR172; c-:-SPL genes; d - AP2 like genes (3) a-miR 172; b-SPL genes; c-AP2 like genes; d-miR156 (4) a-miR156; b-AP2 like genes; c. miR172; d-SPL genes

Genetic Regulation of Juvenile to Adult and Reproductive Phase Transition in Arabidopsis: Roles of miR156, SPL Genes, miR172, and AP2-like Genes

Identification of genes that are associated with the development of male and/or female gametophyte and embryogenesis in plants is facilitated by T-DNA mediated insertional mutagenesis. In an experiment, a transgenic plant was generated by insertion of T-DNA (containing a Kanamycin-resistance gene) into a gene "A". Self-pollination of the To plant generated F1 progeny that segregated in a 2 : 1 ratio for resistance : sensitivity to Kanamycin. These observations indicate that (1) the mutant allele did not segregate from the wild type allele. (2) mutation in gene "A" induces lethality in the male gametophyte. (3) mutation in gene "A" induces lethality in the female gametophyte. (4) mutation in gene "A" induces zygotic lethality. 

T-DNA Insertional Mutagenesis in Arabidopsis: Understanding Zygotic Lethality Through Segregation Distortion

36. 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? (1) The gene product acts as a positive factor of lateral root formation. (2) The gene product acts as a negative regulator of lateral root formation. (3) The gene product is not likely to be involved in lateral root formation. (4) The gene product promotes replication for lateral root development 

Gene Regulation of Lateral Root Formation in Arabidopsis: Negative Regulators and Mutant Phenotypes

35. Which one of the following root initials gives rise to the root vascular system, including the pericycle? (1) Columella initials (2) Epidermal-lateral root cap initials (3) Cortical-endodermal initials (4) Stele initials 

Stele Initials: Originators of the Root Vascular System and Pericycle in Higher Plants

34. The group of cells which generates the vascular tissues including the pericycle in roots of higher plants are called (1) procambium.                                            (2) protoderm. (3) ground meristem.                                                            (4) apical meristem.

Procambium: Origin and Role in Vascular Tissue Development in Roots of Higher Plants

The following statements have been proposed for plant vegetative development: (A) Lateral roots develop from epidermal cells. (B) Shoots axillary meristem develops from shoot apical meristem during differentiation of leaf primordia. (C) Root cap is made of dead cells. (D) Lateral meristem and cylindrical meristem found in roots and shoots results in secondary growth. Which of the above statements are true? (1) (A) and (B) (2) (B) and (D) (3) (A), (B) and (D) (4) (C) and (D) 

Vegetative Development in Plants: Root Cap Cells and Secondary Growth by Lateral Meristems

32. Due to the presence of cellulose in the cell wall of plants, leaf shape is determined in the leaf primorida by (1) rates of cell division. (2) planes of cell division. (3) cell migration. (4) cell-cell interactions. 

Role of Cell Division Planes in Determining Leaf Shape in Plants

31. Following are certain statements regarding seed development in plants: A. During final phase of development embryo's of "orthodox" seeds became tolerant to desiccation, dehydrate losing up to 90% of water B. Dormant seeds will germinate upon rehydration while quiescent seeds require additional treatments or signals for the germination C. Precocious germination is germination of seeds without passing through the normal quiescent and/or dormant stage of development D. Abscisic acid is known to inhibit precocious germination Which one of the following combinations is correct? (1) A, B and C                                                          (2) A, B and D (3) B, C and D                                                         (4) A, C and D 

Seed Development in Plants: Desiccation Tolerance, Dormancy, and Precocious Germination

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? (1) A and B (2) B and C (3) C and D (4) D and A 

Key Stages of Arabidopsis Embryogenesis: Heart and Torpedo Morphogenesis Explained

In which of the following stages of Arabidopsis embryogenesis do the visible distinctions between the adaxial and abaxial tissues of the cotyledons become initially apparent? (1) Globular stage (2) Zygotic stage (3) Torpedo stage (4) Mature stage 

Torpedo Stage of Arabidopsis Embryogenesis: First Visible Adaxial-Abaxial Tissue Differentiation in Cotyledons

In which stage of Arabidopsis embryogenesis is hypophysis first observed? (1) Octant (2) Dermatogen (3) Globular (4) Transition 

Globular Stage of Arabidopsis Embryogenesis: Initial Appearance of Hypophysis and Root Meristem Formation

During which one of the following stages of Arabidopsis embryogenesis, cell elongation throughout the embryonic axis and further development of the cotyledons occur? (1) Globular stage. (2) Torpedo stage. (3) Heart stage. (4) Mature stage. 

Torpedo Stage of Arabidopsis Embryogenesis: Cell Elongation and Cotyledon Development

During development of embryos in plants, PIN proteins are involved in (1) establishment of auxin gradients (2) regulation of gene expression (3) induction of programmed cell death (4) induction of cell division 

Role of PIN Proteins in Establishing Auxin Gradients During Plant Embryo Development

In mature Arabidopsis embryo, root apical meristem consists of cells derived from (1) embryo and apical suspensor cells (2) embryo only (3) suspensor only. (4) hypophysis only. 

Origin of Root Apical Meristem in Arabidopsis: The Role of Hypophysis

Distyly is A. presence of two styles in a flower B. presence of two lengths of styles in a species C. a form of dichogamy. D. a form of herkogamy. Which one of the following options represents all correct statements? (1) B only (2) A and C (3) B and C (4) B and D 

Distyly in Flowering Plants: Floral Dimorphism and Reciprocal Herkogamy Explained

23. Autogamy refers to (1) self-abortion of gametes (2) flower failing to open (3) self-pollination of flowers (4) cross-pollination of flowers 

Autogamy in Plants: Self-Pollination Mechanism and Its Biological Significance

In certain plants, the mechanism where timing of anther dehiscence and stigma receptivity do not coincide to avoid self-pollination is called (1) dichogamy (2) herkogamy (3) monoecy (4) Dioecy 

Dichogamy in Plants: Mechanism for Avoiding Self-Pollination Through Temporal Separation

21. Given below are statements regarding apomixis, i.e. asexual reproduction through seeds Sporophytic apomicts often produce a mix of clonal and sexual progeny B. In gametophytic apomixis, the unreduced central cell gives rise to apomictic embryo C. In pseudogamy the endosperm is formed in the absence of fertilization D. Apomixis can potentially be used to maintain hybrid vigour over many generations Which one of the following options represents the combination of all correct statements? (1) A and C (2) B and C (3) C and D (4) A and D

Key Features of Apomixis in Plants: Sporophytic Apomixis and Maintenance of Hybrid Vigor

20. Following are certain statements regarding apomixis in plants: A. Apomixis cannot be used to maintain hybrid vigor over many generations in plants. B. In sporophytic apomixis maternal genotype is maintained. C. There is an event of meiosis during gametophytic apomixis and is also referred as apomeiosis. D. In diplospory, meiosis of the megaspore mother cell is aborted, resulting in two unreduced spores, out of which one forms the female gametophyte. Which one of the following combinations is correct? (1) A and B                                                    (2) A and C (3) B and C                                                    (4) B and D 

Understanding Apomixis in Plants: Maintenance of Maternal Genotype and Apomeiosis in Diplospory

Match the two columns following asexual reproduction of plants and apomixes: (1) A - (i); B - (ii); C - (iii); D - (iv) (2) A - (ii); B - (iii); C - (iv); D - (i) (3) A - (ii); B – (i); C - (iii); D - (iv) (4) A - (ii); B – (i); C - (iv); D - (iii) 

Asexual Reproduction in Plants: Types and Mechanisms of Apomixis Explained

During embryo germination in a grass family an absorptive organ that forms interface between the embryo and the starchy endosperm tissue is called (1) Coleorhiza (2) Coleoptile (3) Scutellum (4) Mesocotyl 

Role of Scutellum in Grass Seed Germination: Nutrient Absorptive Organ Connecting Embryo and Endosperm

17. A few statements on early developmental stages in plants are given below: A. The cells of flower are diploid in nature. B. Only some specialized cells in reproductive organs undergo meiosis produce haploid cells. C. The haploid cells produced in (B) above, undergo a few normal mitotic cell divisions. D. All the progeny cells produced in (B) above, differentiate either into haploid egg cells or into haploid sperm cells. Which one of the following combinations of above statements is correct? (1) A, B and C                                                (2) B, C and D (3) A, C and D                                                (4) A, B and D

Early Plant Developmental Stages: Meiosis, Mitosis, and Gamete Formation

The development of anthers and male gametophytes is highly conserved among angiosperms. Following are some of the events associated with pollen development, in random order. (a) Microsporogenesis in pollen sac to produce a tetrad. (b) Asymmetric division forming immature pollen grain. (c) Archespore division. (d) Division of generative cell to form two sperm cells. (e) Callose digestion to form free microsperes. Which of the following option represent the correct series of events during pollen development? (1) (a), (b), (c), (d), (e) (2) (c), (a), (e), (b), (d) (3) (a), (c), (d), (b), (e) (4) (c), (e), (a), (b), (d) 

Stages of Pollen Development in Angiosperms: From Archespore to Mature Gametophyte

Which of the following statement is WRONG? (1) Megasporocyte develops within the megasporangium of the ovule (2) Megasporocyte undergoes meiosis to produce four haploid megaspores (3) All the four megaspore undergo several mitotic division to form female gametophyte in most angiosperms (4) Female gametophyte is haploid 

Megasporogenesis and Female Gametophyte Development in Angiosperms: Clarifying Common Misconceptions

Which one of the following statements regarding double fertilization in plants is correct? (1) The same sperm cell fuses with both egg cell and central cell. (2) Two sperm cells fuse with the egg cell. (3) One sperm cell fuses with the egg cell and second with the central cell. (4) Two sperm cells fuse with the central cell. 

Double Fertilization in Plants: Fusion of Sperm with Egg and Central Cell Explained

Sperm cell behaviour during double fertilization in Arabidopsis can be stated as follows. Identify the INCORRECT statement: (1) Pollen tube bursts and discharges sperm cells. (2) Pollen cells produce pollen tubes and enter into female gametophyte. (3) The receptive antipodal cells break down when pollen tube enters the female gametophyte. (4) One sperm nucleus fuses with the egg cell and the other fuses with the central cells. 

Sperm Cell Behavior in Arabidopsis Double Fertilization: Correcting Misconceptions About Antipodal Cells

During reproductive development in plants: (A) male and female gametes are produced as a result of two mitotic divisions after meiosis (B) vegetative cells in pollen contribute to pollen development (C) antipodal provide nourishment to developing embryo (D) Pollen tube ruptures and releases both the male gametes in one of the degenerated synergids Which of the above statement are true? (1) A and B (2) B and D (3) B and C (4) A and D 

Plant Reproductive Development: Roles of Vegetative Cells, Synergids, and Gamete Formation

During double fertilization in plants, one sperm fuses with the egg cell and the other sperm fuses with (1) synergid cell (2) central cell (3) antipodal cell (4) nucellar cell 

Double Fertilization in Angiosperms: Fusion of Sperm with Egg and Central Cell

10. In Arabidoposis gene responsible for formation shoot meristem is (1) Leafy                                                       (2) Agamous (3) Clavata                                                    (4) Wus 

WUSCHEL Gene: Master Regulator of Shoot Meristem Formation in Arabidopsis

Which one of the following transcription factors is important for delimiting the meristematic and elongation zones of roots? (1) SCARECROW (SCR) (2) SHORT ROOTS (SHR) (3) PLETHORA (PLOT) (4) SPEECHLESS (SPCH)

Role of PLETHORA Transcription Factor in Root Meristem and Elongation Zone Regulation

Which would be the result of mutation in SCARECROW genes responsible for radial patterning in roots of higher plants? (1) No apical root formation (2) Root hair will fail to develop (3) Roots with missing cell layer that normally generates cortex and endodermis. (4) Roots will be positively geotropic 

Role of SCARECROW Gene in Root Radial Patterning: Effects of Mutation on Cortex and Endodermis Formation

Which of the following represents the gametophyte generation in plants (1) Ovule (2) Megaspore (3) Embryo sac (4) Egg 

Understanding the Gametophyte Generation in Plants: The Role of the Embryo Sac

In plant lateral root initiates from (1) Pericycle (2) Cortex (3) Pith (4) Endodermisv

Origin of Lateral Roots in Plants: Role of the Pericycle in Root Development

Factor responsible for formation of embryonic axis during early developmental pathway of plant is (1) Auxin gradient (2) Morphogens (3) Orientation of embryo sac (4) Plane of Cell Division 

Role of Auxin Gradient in Embryonic Axis Formation During Early Plant Development

During gametophytic self-incompatibility the primary response is (1) The interaction between the SRK and SCR/SP11 and downstream cellular and molecular events, leading eventually to pollen inhibition (2) S-RNase probably causes degradation of the ribosomal RNA (rRNA) inside ovule of female plant (3) Formation of concentric ring from Golgi (4) Ca2+-dependent signaling cascade in incompatible pollen inhibiting elongation 

Gametophytic Self-Incompatibility: Molecular Mechanism of SRK and SCR/SP11 Interaction Leading to Pollen Inhibition

14. The two cell types, Anchor cell and vulval precursor cells are involved in vulva formation in C. elegans. The following statements are given towards understanding the roles of these two cell types and their signaling activities: A. Anchor cell is a germ cell from the gonad, which sends induction signal to vulva for maintaining differentiation states. B. The six vulval precursor cells, influenced by anchor cell, form an equivalence group C. The cell directly beneath the anchor cell divides to form the central vulval cells, while the two flanking cells divide to become the lateral vulval cells D. The three cells further away from anchor cell generate hypodermal cells E. Lin3 signal from anchor cell forms a gradient and activates vulva forming genes in central and lateral cells F. The Notch-Delta mediated mechanism of restricting adjacent cell fates is called Lateral inhibition. Which combination of the above statements is correct towards vulva formation in C. elegans? (1) A, B and E only (2) A, B, E and F (3) A, B, C and D (4) B, C, D, E and F

Roles and Signaling in Vulva Formation of Caenorhabditis elegans: Anchor Cell, VPCs, and Developmental Fate Decisions

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