Bio April revision T2

The high concentration of auxins causes the

• increase in the elongation of root cells

• increase in the elongation of root and stem cells

• inhibition in the elongation of root cells

• inhibition in the elongation of stem cells

All the following statements are correct, except

• the stem is positive photoropic and negative geotrpic

• the stem is negative geotropic and positive hydrotropic

• the root is negative phototropic and positive hydrotropic

• the root is positive geotropic and positive hydrotropic

The accurate distribution of auxins in the tip of oat coleoptile that is exposed to the light from the right side is .....

• 
• 
• 
• 

The vital functions that help the living organism to adapt with its environment is .....

• respiratioin

• transportation

• movement

• sensation

when carrying out an expirement to verify the phototropism, a stem of plant was exposed to the light from one side only , which of the illustrated regions in the opposite figure has the highest rate of growth ?

• X

• Y

• Z

• L

The structures that are found in Mimosa plant and similar to the action of joints in human are ......

• the leaflets

• the primary rachises

• the secondary rachises

• the pulvini

If the tip of coleoptile is cut, the ------------------

• plant will die

• plant loses its ability to tropism

• plant is not affected

• auxins distribution will be unequal

When a seedling grow in a horizontal position, --------

• the stem will be downward and the root will be upwards against gravity

• Both stem and root will grow downwards

• the stem will be upward and the root will be downward against gravity

• both stem and root grow horizontally

When the plant stem is exposed to light source that is located above the plant, -------

• the stem is directed toward the right side

• the stem is directed toward the left side

• the stem grows vertically upward

• the stem stops growing

When the tip of coleoptile is separated from the remaining coleoptile with mica sheet, there will be no curvature of the stem towards light, because the -------

• auxins are not secreted

• auxins can't diffuse through mica sheet

• auxins are unequally distributed on both sides

• mica sheet killed the plant tip