Human urine is usually acidic because?
 

1.	hydrogen ions are actively secreted into the filtrate.
2.	the sodium transporter exchanges one hydrogen ion for each sodium ion, in peritubular capillaries.
3.	excreted plasma proteins are acidic
4.	Potassium and sodium exchange generates acidity

In photosynthesis, the light-independent reactions take place at?

1. Thylakoid lumen

2. photosystem I

3. photosystem II

4. Stromal matrix

In the mammalian eye, the ‘fovea’ is the center of the visual field, where?

1. high density of cones occur, but has no rods

2. the optic nerve leaves the eye

3. only rods are present

4. more rods than cones are found

Pick up the wrong statement.

Among China rose, mustard, brinjal, potato, guava, cucumber, onion and tulip, how many plants have superior ovary?

1. Five

2. Six

3. Three

4. Four

Name the pulmonary disease in which alveolar surface area involved in gas exchange is drastically reduced due to damage in the alveolar walls.

1. Pleurisky

2. Emphysema

3. Pneumonia

4. Asthma

A column of water within xylem vessels of tall trees does not break under its weight because of?
1. Dissolved sugar in water
2. Tensile strength of water
3. Lignification of xylem vessels
4. Positive root pressure

Acid rain is caused by increases in the atmospheric concentration of?

1. $S{O}_2$ $and$ $N{O}_2$

2. $S{O}_3$ $and$ $CO$

3. $C{O}_2$ $and$ $CO$

4. $O_3$ $and$ $dust$

The enzyme that is not present in succus entericulus is?

1. maltase.

2. nucleases.

3. nucleosidases.

4. lipases.

In which of the following interactions both partners are adversely affected?