Mention the shape of gaurd cells in cyperus.
Guard cells exhibit both kidney-shaped and dumbbell-shaped forms.
12 Class
In which condition transpiration pull will be affected?
Temperature variations between day and night can lead to the formation of gas bubbles, impacting the process of transpiration pull in plants. Fluctuating temperatures can induce the creation of gas pockets, influencing the plant’s ability to draw water through transpiration. Gas bubble formation, influenced by day-night temperature changes, can disrupt the normal transpiration pull in … Read more
Which type of plants have negative root pressure?
Excessive transpiration in plants correlates with a depletion of root pressure, indicating a negative impact on their physiological balance.
Which type of solution will bring about deplasmolysis?
A plasmolysed cell placed in a hypotonic solution undergoes deplasmolysis.
What happens when a pressure greater than the atmospheric pressure is applied to pure water or a solution?
Applying pressure higher than atmospheric to pure water or a solution elevates its water potential. This heightened pressure induces an increase in the system’s overall water potential. The water potential, influenced by external pressure, rises beyond its baseline in response to the applied force. Essentially, elevated pressure results in an augmented water potential within the … Read more
What is osmotic pressure?
Osmotic pressure: Osmotic pressure is the pressure imbalance that halts the solvent’s net movement into a solution through a semipermeable membrane. Equilibrium occurs when the column’s hydrostatic pressure equals the osmotic pressure.
What is genetic variations? Explain the different factors responsible for genetic variations.
Genetic variation refers to the diversity in DNA sequences among individuals within a population, occurring in both germ cells (sperm and egg) and somatic cells (all other cells). Genetic variations are caused by following factors: I. Mutation: • Definition: Sudden, permanent heritable changes. • Types: Gene mutation (point mutation), chromosome structure mutation, chromosome number mutation. • Effect: Alters … Read more
What is isolation? Describe different type of reproductive isolation.
Isolation refers to the division of a species’ population into smaller units, where organisms in these subunits are hindered from interbreeding by barriers known as isolating mechanisms. Different type of reproductive isolation are as follows: I. Geographical Isolation: • Physical barriers like rivers, oceans, mountains, or glaciers divide the original population. • Organisms can’t cross these … Read more
Describe the Urey and Millers experiment.
Stanley L. Miller and Harold C. Urey’s Experimental Support for Oparin’s Chemical Evolution Theory: Apparatus and Procedure: Miller and Urey devised a spark-discharge apparatus, a glass chamber, to experimentally validate Oparin’s chemical evolution theory. The apparatus was sterilized, evacuated, and filled with methane, ammonia, and hydrogen gases in a 1:2:2 ratio. A tube introduced water … Read more