2019 JULY Improvement | HSE +1 Exam | Zoology - Answers

 2019 JULY Improvement (+1)
ZOOLOGY: ANSWERS

1.   d.   Absence of air bladder.                 

2.   Key.

3.   b.   Medulla

4.        

a.   A signal sent out by CNS

↓

b.   Release of a neuro-transmitter substance

↓

c.   Release of Ca²⁺ into the sarcoplasm

↓

d.   Binding of Ca²⁺ with troponin

↓

e.   Remove the mask of active sites for binding myosin

5.  (a) A= Serosa

B= Muscularis

C= Submucosa

D= Mucosa

(b) Villi in small intestine and Rugae in stomach.

6.   Low PO₂, high PCO₂, high H⁺, high temperature.

7.   (a) Cardiac muscle.

(b) It allows the cardiac muscles to contract as a single unit.

8.   (a) True

(b) False. ANF decreases blood pressure.

(c) False. Angiotensin-II activates adrenal cortex to release aldosterone.

(d) True.

9.   (a) Clavicle, Scapula.

(b) Acetabulum.

10. (a) Compound eye: Mosaic vision.

(b) Seminal vesicle: To store sperms.

(c) Arthrodial membrane: Connect the sclerites.

(d) Malpighian tubules: Excretion.

11. (a) Flame cells, Proboscis gland

(b) Flame cells: Phylum Platyhelminthes. E.g. Liver fluke

Proboscis gland: Phylum Hemichordata. E.g. Balanoglossus.

12. (a) Electric synapse: The membranes of pre- and post-synaptic neurons are nearer. Faster impulse transmission.

Chemical synapse: There is a fluid filled space (synaptic cleft) between the presynaptic neuron and postsynaptic neuron.

(b) Rods: Helps in twilight (scotopic) vision.

Cones: Helps in daylight (photopic) vision & colour vision.

13. Hypothalamus and pituitary.

A= Hypothalamus

B= Posterior pituitary

C= Anterior pituitary

D= Portal circulation

14. (a)  SAN → Right atrium → AVN → AV Bundle → Bundle of His → Ventricle.

(b) SA node (SAN)

15. A= Tissue/organ/organ system

B= Bilateral

C= Pseudocoelom

D= Ctenophora

E= Mollusca

F= Hemichordata

16. (a) Cholecystokinin: From gastro-intestinal tract. Function: Stimulates secretion of pancreatic juice.

(b) Gastrin: From gastro-intestinal tract. Function: Stimulates secretion of HCl in gastric glands.

(c) Secretin: From gastro-intestinal tract. Function: Stimulates secretion of water and bicarbonate ions.

17.    

Classification of Enzymes	Reactions
Hydrolases	Hydrolysis of bonds
Lyases	Removal of groups
Oxidoreductases	Oxidation-reduction reactions
Isomerases	Interconversion of molecules
Ligases	Linking together of molecules
Transferases	Transfer of a group

 

18. (a) Thrombin

(b) Activates prothrombin to thrombin.

(c) Calcium ions.