Mark the following statements as ‘True’ or ‘False’:
i) During development cells move by extending their cell processes in all directions without any polarity.
ii) The cytoskeleton of the cell is actively involved in cell movement and cell shape change.
iii) Cadherin on one cell binds strongly to similar cadherins molecules on other cells.
iv) Integrins are cell adhesion molecules that attach cells to other cells at the apical region.
v) Permissive interaction involves gene expression in the induced cell.
vi) Morphogens are paracrine signalling molecules.
vii) In apoptosis the cell organelles are delivered to lysosomes and the cell contents are spilled out.
viii) Cell death by necrosis indicates that cell has undergone a toxic reaction.
ix) Optic cup is induced to form the retinal layers by reciprocal induction from the lens.
x) Pattern formation is the result of morphogenesis.
List at least three stages in gene expression that can be regulated to result in differentiated cell types? Explain any one of them with the help of an example.
See Answer →Draw a well labeled diagram of the internal structures of ovary and describe the structures present in it.
See Answer →Name different stages in the evolution of heart.
See Answer →Write short note on the general structure of heart wall.
See Answer →Briefly discuss the mechanism of pulmonary respiration in frog. How is it different from reptilian mechanism of respiration?
See Answer →Describe the structure of the respiratory system of cartilaginous fishes and state how it differs from that of bony fishes.
See Answer →Fill in the blanks in the following sentences by selecting an appropriate word from those given in the parenthesis after each sentence:
i) The skeleton of the head is known as ……………………. (vertebral column, pelvic girdle, skull).
ii) Cranium encloses and protects the ……………………… (eye, heart, brain).
iii) The brain within the cranium is in contact with the spinal cord through ………………………… an aperture found at the hind end of the cranium (fenestra ovalis, foramen magnum, external nares).
iv) The vertebra with concavity infront and convexity behind is called …………………. type (amphicoelous, procoelous, opisthocoelous).
v) The bone humerus of the upper arm articulates with the pectoral girdle at ……………………… cavity (glenoid, acetabulum, zygapophysis).
vi) Radio-ulna, a composite bone is found in ……..…………….. (rabbit, bat, frog).
See Answer →Mention the two types of endoskeletal structures found in vertebrates. What is the difference between their ground matrix?
See Answer →Explain keratinization in terrestrial vertebrates.
See Answer →Write two important differences between scales of reptiles and fishes.
See Answer →Differentiate between horns and antlers and give an example each of an animal with horn and an antler.
See Answer →List and give one function of the four glands of the skin
See Answer →The special adaptations of birds all contribute to two factors essential for flight namely, more power and less weight. Explain how each of the following contributes to one or the other or both:
(i) Endothermy
(ii) Respiratory system
(iii) Skeleton system
(iv) Excretory system.
See Answer →What are the three main reptile lines that evolved from the amniotes during the Mesozoic era and from which lineage did the present day reptiles evolve? How would you distinguish among the anapsid, diapsid and synapsid types of skull.
See Answer →Distinguish between anurans and urodeles
See Answer →Describe parental care in amphibians
See Answer →Give one word/short answer for the following:
i) Give one prominent difference between sharks and rays.
ii) What kind of tail characterises elasmobranchs?
iii) In what way are sharks well adapted for predatory life habit?
iv) What is the function of the lateral line system in elasmobranchs?
v) How is the Chimera different from sharks and rays?
Describe the water vascular system of a seastar.
See Answer →What are the characteristics of echinderms that are unique to them and not found in other phyla?
See Answer →