Plant Science 491

Front 1

What was the first biotechnology patent issued?

Back 1

It was for a microorganism that could consume hydrocarbons from oil spills.

Front 2

How old can biotechnology be argued to be?

Back 2

Relatively 10,000 years old. It began with the collection of seeds for desirable traits and cross breeding with other species.

In the 1970's the first scientifically genetically modified organisms were created. That sparked the debate and it has been raging ever since.

Front 3

What is a good description for genetic engineering?

Back 3

It is a term limited to the introduction of novel genes into an organism in a laboratory.

Front 4

Is there a large difference between traditional breeding and genetic engineering?

Back 4

It is a very grey area because through traditional breeding plants have hundreds or thousands of genes cross over.

Front 5

What is food security?

Back 5

Where every human being has access to enough food to sustain a healthy and productive life. It has three components:

Food availability;
Access to food; and
Utilization of food.

The reverse scenario is food insecurity.

Front 6

Does the world produce enough food to provide the minimum daily caloric intake requirement for EVERY human being on this planet?

Back 6

Yes, since 1974.

Front 7

What are the causes of food insecurity?

Back 7

Poverty;

Powerlessness to champion their cause;

Violent conflicts;

Discrimination; and,

Demographic factors.

Front 8

How may agricultural biotechnology aid in dealing with food insecurity?

Back 8

Although it is only one part of the equation, it can:

Increase food production per unit area of arable land;

Improve nutrient composition and deliver the requirements in a more efficient manner;

Improve the yield through herbicide pet/pathogen and abiotic stress tolerance;

Can be used as biofactories with plant made pharmaceuticals.

Front 9

What is the practical reasoning of introducing biotechnology into the lifecycle of a plant?

Back 9

It can make growing much more efficient, and every single developmental stage offers opportunity for transgenic enhancement.

Front 10

What is the difference between abiotic stress and biotic stress?

Back 10

Abiotic stress is the negative impact of non-living factors on the living organisms in a specific environment.

Biotic stress occurs as a result of damage done to plants by other living organisms, such as bacteria, viruses, fungi, parasites, harmful insects, and weeds.

Front 11

Why is gene expression regulated?

Back 11

Because without regulated growth results in abnormalities.

Front 12

What is etiolation?

Back 12

It occurs when plants are grown in either partial or complete absence of light, and is characterized by long, weak stems; smaller, sparser leaves due to longer internodes; and a pale yellow colour.

This is a mechanism to increase the likelihood that a plant will reach a light souce, often from under leaf litter or underneath shade from competing plants.

Front 13

In terms of light, how much is needed to start photosynthesis?

Back 13

It can begin with a single photon of light.

Front 14

Describe the hormone group Auxins.

Back 14

Auxins have an essential role in coordination of many growth and behavioural processes in the plant life cycle.

Auxins stimulates cell elongation by stimulating wall loosening factors, such as elastins, to loosen cell walls. It also stimulates cell devision.

Auxin participates in phototropism, geotripism, hydrotropism and other developmental changes. The uneven distribution of auxin, due to environmental cues such as unidirection light or gravity force results in uneven plant tissue growth.

Front 15

Describe the hormone group gibberellins.

Back 15

Gibberellins are plant hormones that regulate growth and influence various developmental processes, including stem elongation, germination, dormancy, flowering, sex expression, enzyme induction, and leaf and fruit senescence.

Front 16

Describe the hormone group cytokinins.

Back 16

Cytokinins promote cell division (or cytokinesis) in plant roots and shoots. They are primarily involved in cell growth and differentiation, but also affect apical dominance, axillary bud growth, and leaf senescence.

Front 17

What are the seven different kinds of hormones important for this course?

Back 17

Auxins;
Gibberellins;
Cytokinins;
Ethylene;
Jasmonic acid;
Salicylic acid; and,
Abscisic acid.

Front 18

Describe the hormone ethylene.

Back 18

It acts at trace levels throughout the life of the plant by stimulating or regulating the ripening of fruit, the opening of flowers, and the abscission (shedding) of leaves.

Front 19

Describe the hormone Jasmonic acid

Back 19

It's major function is regulating plant growth including growth inhibitions, senescence, and leaf abscission.

It has an important role in response to wounding of plants and systemic acquited resistence; when plants are attacked by insects, they respond by releasing JA, which inhibits the insects ability to digest protein.

Front 20

Describe the hormone Salicylic acid.

Back 20

It is a crystalline organic acid and is found in plants with roles in plant growth and development, photosynthesis, transpiration and ion uptake and transport.

It may also play a role in inducing specific changes in leaf anatomy and chloroplast structure, endogenous signalling, and mediating in plant defence against pathogens.

Front 21

Describe the hormone Abscisic acid.

Back 21

ABA-mediated signalling plays an important part in plant responses to environmental stress and pathogens.

It is the 'stress' hormone

Front 22

What are the two most important hormones in terms of biotechnology?

VERY IMPORTANT!!!!!

Back 22

Auxins and cytokinins because they have application in plant cells that can be manipulated in a test tube.

Front 23

A hormone that is released into the air is considered to be ______?

Back 23

Volatile.

Front 24

What are meristems?

Back 24

Meristems are extremely important as they are undifferentiated cells (akin to animal stem cells) and continuously give rise to ne cells and organs.

This is a simple solution to ageing, allowing old organs to die and make new ones (the old leaves fall off and new ones are grown).

Front 25

What are the most active meristems in the plant?

Back 25

The apical meristem, found in teh tip of the shoot and at the tip of the roots.

Front 26

What are the lateral roots formed from?

Back 26

They are not formed from the root merical meristem but an internal meristem.

Front 27

Define mersitem.

THE ROLE OF MERISTEMS ARE VERY IMPORTANT TO KNOW.

Back 27

A meristem is the tissue in most plants consisting of undifferentiated cells, found in zones of the plant where growth can take place.

Front 28

Define pericycle.

Back 28

The pericycle is a cylinder of parenchyma cells that lies just inside the endodermis and is the outer most part of the stele of plants.

In dicots, it also has the capacity to produce lateral roots. Branch roots arise from this primary meristem tissue. In plants undergoing secondary growth, the pericycle contributes to the vascular cambium often diverging into a cork cambium.

Front 29

When thinking of meristematic cell growth in plants, what is it important to appreciate?

Back 29

That every cell is communicating to it's surrounding cells, letting others know what type of cell it will become.

Front 30

What is a leaf primordia?

Back 30

A leaf organ or tissue in its earliest recognizable stage of development.

Cells at the shoot apical meristem summit serve as stems cells to the surrounding peripheral region, where they proliferate rapidly and are incorporated into differentiating new leaf matter.

Front 31

What is photoperiodism?

Back 31

The physiological reaction or oranisms to the length of day or night. It occurs in plants and animals.

Front 32

Define mersitem.

THE ROLE OF MERISTEMS ARE VERY IMPORTANT TO KNOW.

Back 32

A meristem is the tissue in most plants consisting of undifferentiated cells, found in zones of the plant where growth can take place.

Front 33

Define pericycle.

Back 33

The pericycle is a cylinder of parenchyma cells that lies just inside the endodermis and is the outer most part of the stele of plants.

In dicots, it also has the capacity to produce lateral roots. Branch roots arise from this primary meristem tissue. In plants undergoing secondary growth, the pericycle contributes to the vascular cambium often diverging into a cork cambium.

Front 34

When thinking of meristematic cell growth in plants, what is it important to appreciate?

Back 34

That every cell is communicating to it's surrounding cells, letting others know what type of cell it will become.

Front 35

What is a leaf primordia?

Back 35

A leaf organ or tissue in its earliest recognizable stage of development.

Cells at the shoot apical meristem summit serve as stems cells to the surrounding peripheral region, where they proliferate rapidly and are incorporated into differentiating new leaf matter.

Front 36

What is photoperiodism?

Back 36

The physiological reaction or oranisms to the length of day or night. It occurs in plants and animals.

Front 37

What is vernalization?

Back 37

The acquisition of a plant's ability to flower or germinate in the spring by exposure to the prolonged cold of winter.

Front 38

What is epigenetic regulation?

Back 38

The study of inherited changes in phenotype or gene expression caused by mechanisms other than changes in the underlying DNA sequence.

These changes may remain through cell divisions for the remaineder of the cell's life and may also last for multiple generations; however, there is no change in teh underlying DNA sequence of the organism.

Instead, non-genetic factors cause the organism's genes to behave (or "express themselves") differently.

Front 39

How do epigenetic relate to human nutrition.

Back 39

If consumed a food may cause a non-genetic factor that changes a genes expression and causes disease.

Front 40

What is a northern blot?

Back 40

A technique used in molecular biology research to study gene expression by detection of RNA in a sample.

With northern blotting it is possible to observe cellular control over structure and function by determining the particular gene expression levels during differentiation, morphogenesis, as well as abnormal or diseased conditions.

Front 41

What is the life cycle of a plant? (six stages)

Back 41

Zygote formation (fertilization);

Seed/embryogenesis;

Seed germination;

Development of the vegetative phase (roots and shoots);

Formation of sexual organs (flowers); and,

Reproduction - formation of zygote.

Front 42

Plant growth and development, from germination to death is controlled by what two major factors?

Back 42

Genetic makeup of the plant; and,

Environmental factors that influence the expression of the plant genetic makeup.

Front 43

The environment affects plant growth and development describe what they are.

Back 43

Plants heed environmental cues to progress from one developmental stage to the other.

The environmental changes affect hormonal status, which in turn regulate gene expression. Gene expression, in turn, determines growth and development.

Front 44

What to phytohormones control?

Back 44

They are central to growth and development.

Front 45

Describe phytohormones briefly.

Back 45

There are at least 7 different kinds of phytohormones, all of them are small molecules. They are transported in the transpiration stream of the xylem, between cell to cell, and can be released into teh air.

Front 46

Give three unique characteristics of a plant's meristem.

Back 46

Meristems are self-regenerating;

Vegetative meristems can retain their embryonic character for a long time (years in the case of trees); and,

They do not become committed to a differentiation pathway and retain cell division capacity.

Front 47

What are secondary meristems?

Back 47

They are auxillary meristems, derived from the stem apical meristem which produced branches from the main axis..

Front 48

List the types of secondary meristems.

Back 48

Intercalary meristems (present in cereals and other grasses in addition to the apical meristem. These growth zones explain why grasses shoot up after being cut);

Branch root meristems - similar to the pimary root meristem and form from pericycle cells;

The vasuclar cambium - produces woody tissues of stem and roots; and,

Cork cambium - bark or periderm development.

Front 49

What are the three stages of leaf development?

Back 49

Organogenesis - formation of leaf primordia;

Development of suborgan domains - different regions of primordia acquire identity as specific parts of the leaf; and,

Cell and tissue differentiation - cells differentiate in a genetically predetermined manner.

Front 50

What are the four developmental zones of the root tip?

Back 50

The root cap, meristematic zone, elongation zone and maturation zone.

All four of these zones occupy a little more than a millimeter of the tip of an Arabidopsis root.

Front 51

What are the four functions of the developmental zones?

Back 51

The root cap protects the apical meristem from mechanical injury, help perceive gravitational stimulii and secrete substances to make soil penetration easier;

The meristematic zone, located under the root cap generates the primary root;

The elongation zone is the site of rapid cell elongations; and,

The maturation zone, where cells acquire differentiated characteristics. It is not responsible for division or elongation.

Front 52

What is photoperiodism?

Back 52

It is the response to the length of day.

Front 53

What is vernalization?

Back 53

The promotion of flowering brought about by exposure to cold at subsequent higher temperatures.

Vernalization requires stable changes in gene expression, changes that are present in the meristem after the cold treatment. Changes are present after the signal is removed - epigenetic regulation.