1. ______________ develop from ectoderm derived from the mesenchyme.
a) Cartilage
b) Mammalian teeth
c) Nails
d) Hair
Explanation: Mammalian teeth create from ectoderm got from the mesenchyme (the neural crest and the oral ectoderm). The epithelial segments of the stem cells for ceaselessly developing teeth structure from tissue layers called the stellate reticulum and the suprabasal layer of the surface ectoderm.
2. A condition in which tissue groups derived from the ectoderm undergo abnormal development is termed as Ectodermal Dysplasia.
a) True
b) False
Explanation: A condition in which tissue groups derived from the ectoderm (sweat glands, hair, nails, and teeth) undergo abnormal development is termed as Ectodermal Dysplasia, but it is a vague term as there are over 170 subtypes of ectodermal dysplasia. It’s been accepted that the cause of the disease is a mutation or a combination of mutations in multiple genes.
3. _____________ is a type of surface ectoderm.
a) Keratinocyte
b) Schwann cells
c) Astrocyte
d) Pinealocyte
Explanation: Keratinocyte is an example of surface ectoderm cells. Schwann cells are an example of Neural crest cells. Astrocytes and Pinealocyte are examples of Neural tube cells.
4. Which of the following cell types are derived from the mesoderm?
a) Red Blood cells
b) Adherent cells
c) Stem cells
d) Carcinoma cells
Explanation: Red blood cells are derived from the mesoderm. Adherent cells are the cells cultured on solid media requiring support to hold the cells in. Stem cells are either derived from the embryo or from fully developed adult organs. Carcinoma cells are derived from tumors.
5. Mesoderm forms muscles through _____________
a) myogenesis
b) hematopoiesis
c) thrombopoiesis
d) endochondral ossification
Explanation: The process of formation of muscles especially during embryonic development from the mesodermal germ layer is termed as myogenesis.
6. Mesoderm has the ability to induce the formation of the neural plate.
a) True
b) False
Explanation: The neural plate formation process is initiated by the signals sent from the dorsal mesoderm to the ectodermal cells above it to convert into columnar neural-plate cells.
7. The mesoderm appears in the __________ week of embryonic development.
a) third
b) eighth
c) first
d) tenth
Explanation: During the gastrulation period the single-layered blastula develops into a trilaminar (three layered) structure called gastrula. These layers are called germ layers, ectoderm, mesoderm and ectoderm.
8. The paraxial mesoderm is one of the important segments of mesoderm.
a) True
b) False
Explanation: The mesoderm is one of the three germ layers formed during the process of gastrulation. The mesoderm has three important compartments, paraxial mesoderm, lateral plate mesoderm, and intermediate mesoderm.
9. The somitomeres are formed by the paraxial mesoderm, theses somitomeres give rise to the mesenchyme of the head.
a) True
b) False
Explanation: The sclerotomes are formed by the paraxial mesoderm. These sclerotomes give rise to the mesenchyme of the head and further organize into the somites in the occipital and caudal segments, and also give rise to sclerotomes and dermatomes. Sclerotomes form cartilage and bones. Dermatomes give rise to the subcutaneous tissue of the skin.
10. The lateral plate mesoderm gives rise to ____________
a) heart
b) liver
c) pancreas
d) brain
Explanation: The blood vessels, blood cells along with the heart in the circulatory system as well as the limbs’ mesodermal components arise from the lateral plate mesoderm.