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.
Related Questions
Which of the following processes occurs when leaf mesophyll cells in tissue culture revert to an undifferentiated callus?
Differentiation
Redifferentiation
Dedifferentiation
Organogenesis
Which process is demonstrated by the formation of interfascicular cambium from fully differentiated parenchyma cells?
Differentiation
Redifferentiation
Cell elongation
Dedifferentiation
Which of the following cellular processes is responsible for the formation of interfascicular cambium from differentiated parenchyma cells in dicot stems?
Totipotency
Dedifferentiation
Redifferentiation
Differentiation
The archenteron in a developing gastrula will eventually give rise to which structure in the adult organism?
Neural tube
Notochord
Digestive tract
Coelom
Which of the following statements are correct?
I. A multicellular organism is composed of mainly three types of cells
II. Undifferentiated cells are stem cells and are unspecialised cells, which usually possesses the power of division
III. Differentiated cells are post-mitotic cells and are specialised to perform specific functions
IV. Dedifferentiated cells are differentiated cells which revert to undifferentiated state to take over the function of division
I, II and III
II, III and IV
I and IV
All of the above
I. Increased vacuolation
II. Cell enlargement
III. New cell wall deposition
Which of the above are the characteristics of phase of elongation?
Choose the correct option accordingly
I and II
II and III
I and III
I, II and III
The development of interfascicular cambium from mature parenchyma cells between vascular bundles exemplifies:
Redifferentiation
Differentiation
Dedifferentiation
Plasticity
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.
Which of the following exhibits the least plasticity?
Glass
Copper
Steel
Gold
I. Plasmatic growth
II. Differentiation
III. Maturation
IV. Senescence
Identify the correct sequence of the following events occurring in plants and choose the correct option accordingly
I → II → III → IV
I → II → IV → III
IV → III → II → I
IV → I → II → III
