04. Plant Form and Function [DEFINITIONS]

Question 1

Plant Tissue

Answer 1

A tissue is a group of one or more cell types which carries out specialized function(s)

Question 2

Meristems

Answer 2

Plants have undifferentiated tissues called meristems, consisting of cells which constantly divide under suitable conditions and produce new cells.

Question 3

Apical Meristems

Answer 3

These meristems are located at root tips and shoot tips. They add new cells that enable increase in length.

Question 4

Lateral Meristems

Answer 4

Vascular cambium and cork cambium are lateral meristems. They are found in woody plants and involve in secondary growth in increasing circumference of roots and stems.

Question 5

Intercalary Meristems

Answer 5

Some monocots such as grasses show meristematic activity at the bases of stems leaves (nodes) These are known as intercalary meristems.

Question 6

Primary Growth of the Shoot

Answer 6

Elongation of the shoot is due to the activity of primary meristem located in the shoot apex, and is called the primary growth of the shoot.

Question 7

Shoot Apical Meristem

Answer 7

A shoot apical meristem is a dome-shaped mass of dividing cells located at the shoot tip.

Question 8

Plant Tissue System

Answer 8

The new cells originating from the meristems are differentiated to perform specialized functions and form a plant tissue system.

Question 9

Dermal Tissue System

Answer 9

This is the outer protective covering of plants.

Question 10

Ground Tissue System

Answer 10

Ground tissue fills the gap between dermal tissue and vascular tissue, mainly consists of the cortex (outer to vascular tissue) and pith (inner to vascular tissue)

Question 11

Plant Growth

Answer 11

Growth involves irreversible increase of dry mass associated with the development of an organism.

Question 12

Secondary Growth

Answer 12

increase in diameter of stems and roots in plants due to the new cells produced by lateral meristems is called secondary growth.

Question 13

Heartwood

Answer 13

As a woody plant ages, the older layers of secondary xylem no longer transport water and minerals. These layers are called heartwood because they are close to the center of the stem/root.

Question 13

Heartwood

Answer 13

As a woody plant ages, the older layers of secondary xylem no longer transport water and minerals. These layers are called heartwood because they are close to the center of the stem/root.

Question 14

Sapwood

Answer 14

The newest outer layers of secondary xylem, still transport xylem sap are known as sapwood.

Question 15

Growth Rings

Answer 15

The thickness of secondary xylem and the lumen of vessels are larger in periods of warm and wet seasons compared to the other growth season of the year. These differences are visible in a cross section as lighter and darker rings and are called growth rings.

Question 16

Stomata

Answer 16

Stomata are pores surrounded by guard cells in the epidermis of the leaves and stems of plants which can open and close.

Question 17

Guard Cells

Answer 17

Guard cells are modified epidermal cells which have a distinct shape and are the only epidermal cells that contain chloroplasts.

Question 18

Diffusion

Answer 18

In the absence of other forces, the movement of molecules of a substance from a place where it’s more concentrated to a place where it is less concentrated, due to random motion of molecules is called diffusion.

Question 19

Osmosis

Answer 19

Osmosis is a special type of diffusion where free water molecules diffuse across a selectively permeable membrane.

Question 20

Imbibition

Answer 20

The physical absorption of water molecules by hydrophilic materials is called imbibition.

Question 21

Facilitated Diffusion

Answer 21

Facilitated diffusion is the movement of water and hydrophilic solutes across the membranes passively with the help of transport protein that span the membrane.

Question 22

Bulk Flow

Answer 22

Bulk flow is the movement of liquid and materials (entire solution) in response to pressure gradient.

Question 23

Water Potential

Answer 23

The physical property that predicts the direction in which water will flow governed by solute concentration and applied pressure is called water potential.

Question 24

Solute Potential / Osmotic Potential

Answer 24

Solute potential is directly proportional to the molarity of a solution.

Question 25

Pressure Potential

Answer 25

Pressure potential is the physical pressure on a solution

Question 26

Water Potential of a Cell

Question 27

Radial Transport

Answer 27

Transport of water and minerals entered from soil to root cortex into the xylem of the root is known as radial transport.

Question 28

Apoplastic Route

Answer 28

The apoplastic route consists of everything external to the plasma membrane of living cells and includes cell walls, extracellular spaces and the interior of dead cells such as vessel elements and tracheids.

Question 29

Symplastic Route

Question 30

Transmembrane Route

Answer 30

The transmembrane route requires repeated crossing of plasma membranes as water and solutes exit one cell and enter the next.

Question 31

Phloem Translocation

Answer 31

The transport of the product of photosynthesis is carried out by the phloem tissue and is known as phloem translocation.

Question 32

Transpiration

Answer 32

Removal of water from leaves and other aerial parts of the plant body as water vapor by diffusion is known as transpiration

Question 33

Guttation

Answer 33

Due to root pressure, more water enters the leaves than lost by transpiration. This results in removal of water droplets from leaf tips or leaf margins of some herbaceous plants. This process is known as guttation.

Question 34

Nutrition

Answer 34

Nutrition is the process of acquiring raw materials and energy from the environment for the metabolic activities of organisms.

Question 35

Autotrophic Nutrition (Autotropism)

Answer 35

The organisms who exhibit autotropism are autotrophs.

Question 36

Symbiosis

Answer 36

Symbiosis is an ecological relationship in which two species live in close contact with each other.

Question 37

Mutualism

Answer 37

Mutualism is a symbiotic relationship in which both participants are benefitted.

Question 38

Commensalism

Answer 38

It is an interaction between two species in which benefits one of the species and neither harms nor benefits the other.

Question 39

Parasitism

Answer 39

it is a close association between two different species which is beneficial to one (the parasite) and harmful to the other (the host)

Question 40

Carnivorous Plants

Answer 40

These plants are photosynthetic but obtain nitrogen and minerals by killing and digesting insects and other small animals.

Question 41

Essential Elements

Answer 41

Elements which are required for a plant to complete its life cycle and produce another generation.

Question 42

Macronutrients

Answer 42

Plants need these elements in large amounts.

Question 43

Micronutrients

Answer 43

Plants require these elements in small amounts.

Question 44

Fertilization

Question 45

Seed

Answer 45

Seed is the dispersal unit of seed plants which contains the embryo and stored food, surrounded by the seed coat.

Question 46

Fruit

Answer 46

Fruit protect the enclosed seeds.

Question 47

Photomorphogenesis

Answer 47

Light triggers many key events in plant growth and development, collectively called photomorphogenesis.

Question 48

Seed Germination

Question 49

Plant Spacing

Question 50

Photoperiod

Answer 50

The photoperiod is the interval in a 24hour period in which the plant gets exposed to light.

Question 51

Phototropism

Answer 51

The growth of a shoot towards light (positive) or away from it (negative)is called phototropism

Question 52

Gravitropism

Answer 52

The shoot of the plant grows upwards while root grows downwards, due to their response to gravity or gravitropism.

Question 53

Hormones

Answer 53

Hormones in general are signaling molecules which are produced in small quantities, get transported from the place they are produced to other parts of the organism and trigger responses in target cell or/and effect on plant growth and development.

Question 54

Stress

Answer 54

Certain factors in the environment may have potentially adverse effects on plants survival, growth and reproduction. This is stress.

Question 55

Drought Stress

Answer 55

Plants may wilt when water loss by transpiration exceeds water absorption.

Question 56

Cold Stress

Answer 56

When the cell membrane cools below a critical temperature it looses its fluidity due to the lipids become locked in to crystalline structure.

Question 57

Salt Stress

Answer 57

An excess if salts (high salinity) in soil lowers the water potential of soil resulting in reduced water potential gradient from soil to root.

Question 58

Biotic Stress

Answer 58

How plants defend themselves against pest and pathogens attack