Tag: growth and development
Questions Related to growth and development
The sequence of various components of a growth curve are
-
Lag, log, stationary
-
Log, lag, stationary
-
Log, stationary, lag
-
Stationary, log, lag
Maximum of growth occurs in
-
Exponential phase
-
Decline phase
-
Stationary phase
-
Lag phase
A tracheid is distinguished from a vessel elements on the basic of.
-
Length
-
Thickness
-
Side-wall pitting
-
End-wall perforation
What is the maximum period of growth?
-
Slow growth rate
-
Steady growth rate
-
Speedy growth rate
-
Senescence phase
If division and differentiation are cocurrent then growthi will be
-
Geometric
-
Logistic
-
Linear
-
Infinite
There are two types of population growth, geometric growth and logistic growth. Geometric growth is also called as exponential growth. Logistic growth is S shaped growth. Arithmetic growth is a linear growth. During cell division, cell divides into two. It increases cell number. During cell differentiation, cell specializes into different cell type. If division and differentiation are cocurrent then there will be negative control. It will regulate the cell division. Hence, the growth will be logistic.
In signoid growth curve, upper asymptote represents period of
-
Establishment
-
Negative acceleration
-
Positive acceleration
-
Equilibrium
In a sigmoid growth curve, there are three phases, lag phase, exponential phase and steady state phase. The upper limit of the curve is called as upper asymptote. It represents the period of equilibrium. At this stage, birth rate and death rate are at balance. It is said to be at equilibrium because at this stage, there is equilibrium between biotic potential and environmental resistance.
State whether the following statements are true or false.
Ethylene stimulates leaf release, while auxin keeps leaves from falling.
-
True
-
False
Ethylene is a gaseous hormone which stimulates the transverse growth but inhibits the longitudinal growth. Auxin delays the abscission of young leaves and provides nutrition to it so that they do not die down while ethylene increases the senescence of leaves and flowers and produces more gas which leads to loss of leaves.
Which of the following is not a feature of a J-shaped growth form of population?
-
It is found in stable type of population.
-
Exponential phase is very rapid.
-
A crash phase occurs at the end of the growth.
-
Environmental resistance does not operate.
J-shaped growth curve is a curve on a graph that records the situation in which, in a new environment, the population density of an organism increases rapidly in and exponential or logarithmic form, but then stops abruptly as environmental resistance or some other factor suddenly becomes effective. The actual rate of population change depends on the biotic potential and population size. It may be summarized mathematically as
Because of the which of the following reason/s, growth stops completely during the stationary phase?
-
Lack of nutrients
-
Saturation of nutrients
-
Over availability of nutrients
-
None of the above
The stationary phase is the phase in which the growth of lant generally stops and the plant proceeds towards maturity it may occur due to the lack of nutrients majorly seen in the unfavourable season.
Incorrect about geometrical growth
-
After mitosis both daughter cells retain the capacity of division
-
Growth pattern follows sigmoid curve
-
Less common than arithmetic growth in the plants
-
Growth rapidly increases
In geometrical growth both the progeny cells following mitotic cell division retain the ability to divide and continue to do so. However, with a limited supply of nutrients, the growth becomes slow which lead to the stationary stage. A sigmoid curve is the characteristic of organism living is the natural environment.