Summer Term Flashcards
Which phytohormone is primarily responsible for cell elongation in plant shoots?
Auxin
5 Major Groups of Phytohormones in Higher Plants
Auxins
Gibberellins
Cytokinins
Abscisic Acid (ABA)
Ethylene
Gibberellins were first discovered in which type of plant?
Rice
Which hormone is known as the “stress hormone” in plants?
ABA: abscisic acid
List the main functions of gibberellins in plants
Germination of seeds
Stress response
Elongation of internodes
Promotes flower and fruit growth
Encourages cell division
Describe the effects of ethylene on plant growth and development.
Stimulates leaf and flower senescence
Inhibits shoot growth outside the seedling stage
Affects neighboring plants
Induces flowering in pineapples
Used in climacteric fruit ripening
What are the primary applications of auxins in viticulture?
Rooting powders for cuttings
Foliar sprays to improve fruit set and berry size
Explain the role of abscisic acid in plant stress responses.
Induces stomatal closure
Controls seed dormancy
Produced during osmotic stress
Important in environmental stress responses and pathogen defense
Who first discovered auxins in the late 19th century?
Darwin
What is the most important auxin?
Indol-3-acetic-acid (IAA)
Which phytohormone is used to stimulate seed germination and internode elongation?
Gibberellins
Which natural cytokinin is an adenine-type cytokinin?
Zeatin
Abscisic Acid (ABA) is antagonistic to which other phytohormones?
Gibberellins and some Auxins
Ethylene production can be stimulated by which phytohormone?
Auxin
What is the active component of ethylene discovered by Dimitry Neljubow?
Ethylene
Which synthetic auxin is used in rooting powders to promote lateral root growth?
IBA (Indole-3-butyric acid)
What is the chemical formula for alcohol?
C6H12O6 + yeast 2C2H6O + 2CO2
What are the three steps of the Calvin cylcle?
Carboxylation, reduction, regeneration
Name some factors affecting photosynthesis?
- Light intensity
- Temperature
- CO2
- O2
- Water & humidity
- Leaf Age
- Leaf insertion
- Nutrient supply
Transpiration: How can the water flow upwards against gravity???
Capillary action from pressure in soil and roots.
What factors effect the rate of
transpiration?
- Humidity
- Temperature
- Light (photosynthesis and CO2
requirements) - Wind
- Water deficiency
How can we measure water deficiency?
Measure the leaf water
potential using a pressure
chamber
What is a gene?
-basic unit of heredity
-Sequence of DNA
-A set of instructions that is
translated into RNA for
Protein synthesis
What are the 3 components of Nucleic acids?
- Nitrogenous base
- A ribose (5 carbon sugar)
- Phoshate group
What is DNA made up of?
DNA is made up of chains of
Deoxyribose nucleotides with
A, G, C and T bases
What is RNA made up of?
RNA is made up of chains of
Ribose nucleotides with A, G, C
and U bases
_____________ is the building blocks for proteins?
amino acids
What are the two types of cell division?
Mitosis and Meiosis
Who discovered the principals of heredity?
