The type of fruit that develops without fertilization, such as banana, is called:
A. True fruit
B. Aggregate fruit
C. Parthenocarpic fruit
D. Multiple fruit
Answer: Option C
Solution (By JKSSB Mock Tests)
Parthenocarpy is the development of fruit without fertilization, leading to seedless fruits like commercial banana, navel orange, and some grapes. It can be natural or induced by hormones. True fruits develop from ovary after fertilization.
Consider the following statements about carbohydrates:
1. Glucose is a monosaccharide.
2. Sucrose is a disaccharide.
3. Cellulose is a storage polysaccharide in plants.
Which of the above is/are correct?
Explanation:
Glucose is a monosaccharide, sucrose a disaccharide (glucose+fructose). Cellulose is a structural polysaccharide, not storage; starch is storage. So 3 is incorrect.
In plant physiology, the 'Transpiration pull' theory, also known as the cohesion-tension theory, was proposed to explain the ascent of sap in tall trees. The key forces involved are:
A.Osmotic pressure in the leaves
B.Root pressure and capillarity
C.Cohesion between water molecules, adhesion to xylem walls, and tension created by transpiration
Explanation:
The cohesion-tension theory, primarily proposed by Dixon and Joly (and later supported by Denison), is the most widely accepted mechanism for the ascent of sap in tall trees. It relies on the physical properties of water. Transpiration from the leaves creates a negative pressure (tension) in the xylem. This tension pulls the water column upwards. The water column remains unbroken due to the high cohesive force between water molecules (hydrogen bonding) and the adhesive force of water to the hydrophilic walls of the xylem vessels and tracheids. This creates a continuous, passive pull from the top.
Explanation:
Cotyledons are seed leaves that store food (starch, proteins, lipids) for the developing embryo and may become photosynthetic after germination. Monocots have one, dicots two. Radicle is root, plumule shoot, seed coat protects.
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