plant growth and development

Question 1

all cells of a plant are descendants of the

Answer 1

zygote

Question 2

development is the sum of

Answer 2

growth and differentiation

Question 3

development of mature plant from a zygote follows a

Answer 3

precise and highly ordered succession

Question 4

the first step in the process of plant growth is

Answer 4

seed germination

Question 5

in the absence of favourable conditions seed

Answer 5

does not germinate and undergoes a period of suspended growth and rest

Question 6

the most fundamental and conspicuous characteristic of a living being

Answer 6

growth

Question 7

what is growth

Answer 7

irreversible and permanent increase in size of an organ or its parts or an individual cell

Question 8

generally growth is accompanied by

Answer 8

metabolic processes

Question 9

plant growth is unique because

Answer 9

plants retain the capacity to grow throughout their life. this is because of the presence of meristems at certain locations of the plant body. cells of this meristem retain the ability to self perpetuate and divide

Question 10

what is open form of growth

Answer 10

the form of growth where new cellls are constantly being added to the plant body by activity of meristem

Question 11

the product of meristematic division

Answer 11

loses the ability to divide and these cells make up the plant body

Question 12

what meristems are responsible for the axial growth is plant

Answer 12

root apical and shoot apical meristem contribute to primary growth and elongation of the plants along their axis

Question 13

meristems that cause increase in girth of the axis of a plant

Answer 13

secondary meristems, interfascicular cambium, cork cambium

Question 14

growth at cellular level is a consequence of

Answer 14

increase in amount of protoplasm

Question 15

since increase in protoplasm is difficult to measure directly

Answer 15

a quantity that is proportional to it is measured like fresh weight, dry weight, length, area, volume, number of cells

Question 16

a maize seed gives rise to

Answer 16

17500 cells per hour

Question 17

a watermelon increases its size u upto

Answer 17

3.5 lakhs times

Question 18

growth is pollen tube is measured by ; dorsiventral leaf

Answer 18

increase in its length; increase in surface area

Question 19

the period of growth is fixed divided into

Answer 19

meristematic, elongation, maturation

Question 20

the cells at the root apex and shoot apex represent

Answer 20

meristematic phase of growth

Question 21

cells of region of meristematic activity

Answer 21

rich in protoplasm, conspicuous nucleus, vacuoles usually absent, cell wall is primary, thin with abundant plasmodesmatal connections.

Question 22

the phase of elongation

Answer 22

increased vacuolation, new cell wall deposition, cell enlargement

Question 23

phase of maturation

Answer 23

maximum size in terms of cell wall thickening and protoplasmic modifications

Question 25

increased growth per unit time is called

Answer 25

growth rate

Question 26

arithmetic growth

Answer 26

after a mitotic cell division, only one of the daughter cells divides further, the other one differentiates and matures L1=L0+rt

Question 27

geometrical/logarithmic growth

Answer 27

initial growth is slow which increases rapidly at an exponential rate, both progeny divide further. with limited nutrient supply, the growth leads to a stationary phase, a sigmoid curve is obtained W1=W0e^rt

Question 28

in geometric growth, r is

Answer 28

growth rate and the measure of the ability of plant to new plant material called as efficieny index

Question 30

cells derived

Question 31

the cells derived from root apical and shoot apical meristems and cambiums

Answer 31

differentiate to form different functions

Question 32

during differentiation, a cell undergoes few to major

Answer 32

structural changes in their cell wall and cytoplasm

Question 33

its differentiation in plants open, why?

Answer 33

yes, because the cells arising out of the same meristems have different structures at maturity, the final structure at maturity is also determined by the location of the cell

Question 34

what is plasticity

Answer 34

plants follow different pathways in response to environment or phases of life to form different structures

Question 35

heterophyll due to life stage example

Answer 35

cotton, coriander, larkspur

Question 36

heterophylly due to environment

Answer 36

buttercup

Question 37

development in plants is under control of

Answer 37

intrinsic and extrinsic factors

Question 38

intrinsic factor

Answer 38

intracellular(genetic) and intercellular ( chemicals like pgh regulators),

Question 39

extrinsic factors

Answer 39

light, water oxygen, nutrients, temperature