Plant Structure, Growth and Reproduction Flashcards
Which process is linked to the plant adaptation of having bright colors
Pollination
Describe the conditions needed for seed germination.
-water needed to rehydrate the seed
-gibberellin active after water absorbed
-gibberellin needed to produce amylase;
-water needed to allow substances inside the seedling to be transported;
-oxygen needed for (aerobic) cell respiration;
-warmth needed to speed up metabolism/enzyme activity;
-warmth indicates that it is a favourable season for germination/spring;
-some seeds need a cold period to stimulate germination;
-some seeds need fire to stimulate germination
-some seeds need to pass through an animal (gut) to stimulate germination
In long day plants…
Levels of Pfr activate genes to promote flowering
In short day plants…
high levels of Pfr inhibit flowering by inhibiting gene expression
Pfr levels increase when..
there is more sunlight exposure
What is the active form of phytochrome?
Pfr
What is the inactive form of phytochrome?
Pr
Short day plants must have…
at least 12 hours of uninterrupted night in order to flower
Define seed dispersal and its purpose.
Process in which seeds move away from the parent plant to prevent resource competition.
What is the process of pollination?
When pollen (from the anther) is transferred to/ placed on the stigma of a flower (by means/ vectors of animals, wind, or water)
What happens when a seed germinates?
The seed begins to sprout (dependent variable in seed germination experiment)
Describe the effect of drop height on distance traveled by seeds.
Lower drop height means the seed as an increased chance of simply landing on the ground. Higher drop height means increased chance that the distance will increase because the likelihood of being caught by wind increases.
State some advantages of seed dispersal via animals.
-Deposited in feces with organic matter
-Digestion may crack seed coat, allowing better germination
-Further distance travelled
State the disadvantages of seed dispersal.
-Deposited in a poor environment
-Predation
Magnification=
image size/actual size (in um)
What aspects must be included in a seed germination experiment?
-Control
-Independent variable
-Dependent Variable (how many seeds have sprouted)
Clue: Plant has Flowers
Classification: Angiospermophyta
Clue: Plant has cones
Classification: Coniferophyta/ Gymnospermophyta
Clue: Plant does not produce seeds, has fern-like leafs
Classification: Phylum Filicophyta
Clue: Plant does not have vascular tissue
Classification: Phylum Bryophyta
What allows almost all plants to have indeterminate growth?
meristems
What is auxin?
A plant hormone that shifts gene expression in a plant to loosen plant cell walls to cause elongation on the shaded side of the plant, resulting in phototropism
What is the role of auxin efflux pump?
Utilizes ATP to pump auxin to the shaded side of the plant stem.
Cell division occurs at a high rate in the….
plant meristem
Steps of Micropropagation
- Uses the shoot apex which is sterilized and placed into a sterile nutrient agar gel.
- This agar gel contains high concentrations of auxin which stimulates growth and cell division.
- The shoots, after the roots have developed, can be separated and transferred to soil to create additional plants.
What are the two types of meristems found in plants?
Apical and Lateral
Compare growth due to apical vs. lateral meristems.
-Both apical and lateral meristems rely on totipotent cell divisions for growth.
-Meristems are regions where cells continue to divide and grow.
-Apical meristems contribute to vertical growth while lateral meristems increase diameter.
-Apical meristems produce new leaves and flowers while lateral meristems produce new xylem and phloem.
Auxin always changes….
gene expression
What is photoperiodism?
Response of the plant to length of night