Q.1 Which gene is primarily responsible for body segmentation in Drosophila?
Hox gene
Segmentation gene
Pax gene
Notch gene
Explanation - Segmentation genes control the formation of repeated segments in Drosophila during early embryogenesis.
Correct answer is: Segmentation gene
Q.2 Mutations in the SHH gene in humans can lead to which condition?
Polydactyly
Albinism
Down syndrome
Hemophilia
Explanation - Sonic Hedgehog (SHH) signaling is critical for limb patterning; mutations can cause extra fingers or toes.
Correct answer is: Polydactyly
Q.3 Homeotic genes determine:
Cell division rate
Organ identity along the body axis
DNA replication accuracy
RNA splicing
Explanation - Homeotic genes specify which structures develop in particular segments of the body.
Correct answer is: Organ identity along the body axis
Q.4 Which signaling pathway is crucial for early embryonic patterning?
Wnt signaling
Insulin signaling
TGF-beta signaling
cAMP signaling
Explanation - Wnt signaling regulates cell fate, axis formation, and organogenesis in early embryos.
Correct answer is: Wnt signaling
Q.5 The ZPA (Zone of Polarizing Activity) in limb development secretes which morphogen?
BMP
FGF
SHH
Hox
Explanation - The ZPA secretes Sonic Hedgehog (SHH) to establish anterior-posterior limb patterning.
Correct answer is: SHH
Q.6 Mutations in PAX6 gene affect development of:
Heart
Lungs
Eyes
Kidneys
Explanation - PAX6 is a master regulatory gene for eye formation; mutations can lead to aniridia or other eye defects.
Correct answer is: Eyes
Q.7 Which of the following is a transcription factor important for mesoderm formation?
Brachyury
Sonic Hedgehog
Wnt
Hox
Explanation - Brachyury is a transcription factor essential for mesoderm specification and notochord development.
Correct answer is: Brachyury
Q.8 Hox genes are organized in clusters and exhibit:
Random expression
Colinearity
Binary expression
Negative feedback loops
Explanation - Hox genes are expressed in a spatial order corresponding to their position within the cluster, known as colinearity.
Correct answer is: Colinearity
Q.9 Retinoic acid influences development primarily by:
Inhibiting DNA replication
Regulating Hox gene expression
Promoting apoptosis
Enhancing protein degradation
Explanation - Retinoic acid acts as a signaling molecule controlling Hox gene expression and axial patterning.
Correct answer is: Regulating Hox gene expression
Q.10 The term 'maternal effect gene' refers to genes that:
Are expressed only in zygotes
Encode enzymes for metabolism
Are transcribed in the mother to influence early embryo
Control adult organ functions
Explanation - Maternal effect genes are expressed in the mother and their products are deposited in the egg to guide early development.
Correct answer is: Are transcribed in the mother to influence early embryo
Q.11 The neural tube in vertebrates is formed from:
Mesoderm
Endoderm
Ectoderm
Trophoblast
Explanation - The neural tube develops from the ectoderm during neurulation and gives rise to the central nervous system.
Correct answer is: Ectoderm
Q.12 Which molecule acts as a morphogen during limb patterning?
Insulin
SHH
ACTH
Adrenaline
Explanation - Sonic Hedgehog (SHH) acts as a morphogen to establish gradients that guide limb formation.
Correct answer is: SHH
Q.13 The term 'epigenetics' in developmental genetics refers to:
Changes in DNA sequence
Heritable changes in gene expression without DNA sequence alteration
Protein mutations
RNA splicing errors
Explanation - Epigenetics involves modifications like DNA methylation or histone modification that affect gene expression and development.
Correct answer is: Heritable changes in gene expression without DNA sequence alteration
Q.14 BMP signaling is crucial for:
Neural induction
Mesodermal differentiation
Apoptosis in digit separation
All of the above
Explanation - Bone Morphogenetic Proteins (BMPs) regulate neural, mesodermal development and programmed cell death during morphogenesis.
Correct answer is: All of the above
Q.15 Teratogens affect development by:
Altering maternal blood pressure
Causing congenital malformations
Increasing adult metabolism
Enhancing immune response
Explanation - Teratogens are agents like chemicals or radiation that disrupt normal development and cause birth defects.
Correct answer is: Causing congenital malformations
Q.16 The zona pellucida of an egg is important for:
DNA replication
Sperm binding and fertilization
RNA transcription
Cytokinesis
Explanation - The zona pellucida is a glycoprotein layer that mediates sperm recognition and prevents polyspermy.
Correct answer is: Sperm binding and fertilization
Q.17 Which transcription factor is critical for neural crest development?
SOX9
MYC
PAX6
BRCA1
Explanation - SOX9 regulates differentiation and migration of neural crest cells during embryogenesis.
Correct answer is: SOX9
Q.18 Defects in the Notch signaling pathway can result in:
Polydactyly
Heart defects and developmental syndromes
Albinism
Diabetes
Explanation - Notch signaling is essential for cell fate decisions; mutations can lead to congenital heart diseases.
Correct answer is: Heart defects and developmental syndromes
Q.19 The first zygotic gene to be transcribed in Drosophila is called:
Gap gene
Maternal effect gene
Pair-rule gene
Zygotic gene
Explanation - Gap genes are the first zygotic genes expressed and define broad embryonic regions.
Correct answer is: Gap gene
Q.20 Which gene family is highly conserved across animals and specifies segmental identity?
Hox genes
Pax genes
SHH genes
BMP genes
Explanation - Hox genes are conserved transcription factors that determine segment identity along the body axis in all bilaterians.
Correct answer is: Hox genes
Q.21 Anterior-posterior axis in vertebrates is primarily established by:
SHH gradient
BMP gradient
Wnt signaling gradient
FGF gradient
Explanation - Wnt signaling gradients in early development help define the anterior-posterior body axis.
Correct answer is: Wnt signaling gradient
Q.22 Mutations in the FGFR gene family can cause:
Achondroplasia
Polydactyly
Cleft palate
All of the above
Explanation - Fibroblast growth factor receptors (FGFRs) play roles in skeletal and craniofacial development; mutations lead to multiple congenital disorders.
Correct answer is: All of the above
Q.23 Which structure gives rise to the central nervous system?
Neural crest
Neural tube
Somites
Endoderm
Explanation - The neural tube forms during neurulation and develops into the brain and spinal cord.
Correct answer is: Neural tube
Q.24 Limb bud outgrowth is primarily induced by which factor?
FGF
BMP
SHH
Wnt
Explanation - Fibroblast growth factors (FGFs) secreted from the apical ectodermal ridge promote limb bud proliferation and outgrowth.
Correct answer is: FGF
Q.25 The term 'morphogen' refers to:
A molecule that provides positional information to cells
An enzyme that metabolizes DNA
A protein that transports oxygen
A molecule that inhibits gene expression
Explanation - Morphogens form concentration gradients that guide cell differentiation and tissue patterning during development.
Correct answer is: A molecule that provides positional information to cells