Prepare for NEET Biology Plant Growth and Development with MCQs & PYQs on NEET.GUIDE. Get free practice, previous year questions, and expert insights on plant hormones and growth regulators.
During human embryonic development, the formation of the primitive streak marks a crucial step. Which of the following statements regarding the primitive streak is INCORRECT?
It marks the beginning of gastrulation.
It defines the embryo's axes.
It is the source of mesoderm and endoderm.
It persists throughout development.
A mutation affects the function of the Hox genes in a developing Drosophila embryo. Which of the following is the MOST likely consequence?
Premature termination of embryonic development.
Failure of gastrulation.
Homeotic transformations, leading to segments developing with characteristics of other segments.
Lack of differentiation of germ layers.
The process of organogenesis in vertebrate embryos is heavily influenced by epithelial-mesenchymal transitions (EMTs). Which of the following is NOT a characteristic feature of EMT during organogenesis?
Loss of cell adhesion molecules.
Increased cell motility.
Increased cell proliferation within the epithelium.
Degradation of the extracellular matrix.
Which of the following extra-embryonic membranes in amniotes primarily functions in waste storage?
Chorion
Amnion
Yolk sac
Allantois
The archenteron in a developing gastrula will eventually give rise to which structure in the adult organism?
Neural tube
Notochord
Digestive tract
Coelom
During oogenesis in mammals, polar bodies are formed. Which statement best describes the function of polar bodies?
To provide nutrients to the developing oocyte.
To allow for the reduction of chromosome number while retaining most of the cytoplasm in the oocyte.
To initiate the process of fertilization.
To guide the sperm towards the oocyte.
A plant hormone promotes bolting in rosette plants and is also antagonistic to the effects of abscisic acid on alpha-amylase activity. This hormone also plays a key role in apical dominance. Which of the following hormones fits this description?
Gibberellin
Auxin
Cytokinin
Ethylene
Which PGR is most likely responsible for the phenomenon observed when a plant bends towards a light source, even if the light source is unidirectional and doesn't illuminate the entire plant?
Cytokinin
Gibberellin
Auxin
Abscisic Acid
Ethylene is unique among plant growth regulators due to its:
Ability to promote cell division
Role in seed dormancy
Gaseous nature
Synthesis in the root apical meristem
Which of the following combinations of plant growth regulators are antagonistic in their action on apical dominance?
Auxin and Gibberellin
Cytokinin and Ethylene
Gibberellin and Abscisic Acid
Auxin and Cytokinin
