Which of the following factors is responsible for the formation of concentrated urine?
maintaining hyperosmolarity towards inner medullary interstitium in the kidneys.
Secretion of erythropoietin by Juxtaglomeular complex.
Hydrostatic pressure during glomerular filtration
low levels of antidiuretic hormone
A.
maintaining hyperosmolarity towards inner medullary interstitium in the kidneys.
The proximity between loop of henle and vasa recta as well as counter current in them help in maintaining as increasing osmolarity towards the inner medullary interstitium. This mechanism help to maintain a concentration gradient in medullary interstitium so human urine is nearly four times concentrated than initial filtrate formed.
The ciliated epithelial cells are required to move particles or mucus in a specific direction. In humans, these cells are mainly present in
Fallopian tubes and Pancreatic duct
Eustachian tube and Salivary duct
Bronchioles and Fallopian tubes
Bile duct and Brochioles
Grass leaves curl inwards during very dry weather. Select the most appropriate reason from the following
flaccidity of buliform cells
shrinkage of air spaces in spongy mesophyll
tyloses in vessels
closure of stomata
Match the following organisms with their respective characteristics :
| A. Pila | i. Flame cells |
| B. Bombyx | ii. Comb plates |
| C. Pleurobrachia | iii. Radula |
| D. Taenia | iv. Malpighian tubules |
Select the correct option from the following:
A - iii; B - iv; C - ii; D - i
A - ii; B - iv; C - iii; D - i
A - iii; B - ii; C - iv; D - i
A - iii; B - ii; C - i; D - iv
What is the site of perception of photoperiod necessary for induction of flowering in plants?
Pulvinus
Shoot apex
Leaves
Lateral buds
Tidal Volume and Expiratory Reserve Volume of an athlete is 500 mL and 1000 mL, respectively. What will be his Expiratory Capacity if the Residual Volume is 1200 mL?
1700 mL
2200 mL
2700 mL
1500 mL
Thiobacillus is a group of bacteria helpful in carrying out
Chemoautotrophic fixation
Nitrification
Denitrification
Nitrogen fixation
Identify the cells whose secretion protects the lining of gastro-intestinal tract from various enzymes.
Goblet cells
Oxyntic cells
Duodenal cells
Chief cells
Which of the following statements is not correct?
The hydrolytic enzymes of lysosomes are active under acidic pH
Lysosomes are membrane bound structures
Lysosomes are formed by the process of packaging in the endoplasmic reticulum
Lysosomes have numerous hydrolytic enzymes
