Class 2

Question 1

Seed

Answer 1

A matured ovule containing an embryo that is the result of sexual fertilization (pollination)

Question 2

Embryo

Answer 2

baby plant

Question 3

Endosperm

Answer 3

starchy food for the baby plant (not all seed have this, i.e. orchids that get nutrients from fungi)

Question 4

Seed coat

Answer 4

hard coat

Question 5

Fruit

Answer 5

a seed-bearing structure formed by the ovary after flowering

Question 6

Dry fruit

Answer 6

Definition: Fruits that become dry and hard at maturity, with little to no fleshy tissue.
Seed Dispersal: Often rely on mechanical or environmental factors (e.g., wind, animals, or bursting) to release seeds.
Examples:

Dehiscent Dry Fruits: Split open at maturity to release seeds.
    Legume: Pea pods, beans.
    Capsule: Poppy, cotton.
Indehiscent Dry Fruits: Do not split open; seeds remain enclosed.
    Achene: Sunflower seeds.
    Nut: Acorn, hazelnut.
    Samara: Maple keys (winged seeds).

Question 7

Dehiscent fruits

Answer 7

Definition: Fruits that split open naturally at maturity to release their seeds.
Seed Dispersal: Seeds are freed from the fruit through splitting, often relying on environmental factors like wind or gravity for dispersal.
Examples:

Legumes: Pea, bean, lentil (split along two seams).
Capsules: Poppy, cotton (split in multiple ways to release seeds).
Follicles: Milkweed (split along one seam).
Siliques: Mustard (split into two halves, leaving a central partition).

Question 8

Indehiscent fruit

Answer 8

Definition: Fruits that do not split open at maturity; the seeds remain enclosed within the fruit.
Seed Dispersal: Seeds are dispersed along with the entire fruit, often relying on animals, water, or wind.
Examples:

Nuts: Acorn, hazelnut (hard shell protects the seed).
Achenes: Sunflower seeds (small, dry fruit with a single seed).
Samara: Maple (winged fruit).
Grains (Caryopsis): Wheat, corn, rice (seed fused with the fruit wall).

Question 9

Climacteric

Answer 9

produces ethylene, a gas that speeds ripening. This is important because climacteric fruit can be picked while it is not ripe and can continue to ripen after

Question 10

Orthodox

Answer 10

Can be dried to 10% or less moisture content
Can be stored at subfreezing temperatures
Can be stored for long periods
Tolerate desiccation to low moisture contents
Seed longevity increases with decreasing moisture

Question 11

Recalcitrant

Answer 11

Cannot be dried below 25–45% moisture content
Cannot be stored below freezing
Storage at ambient temperatures is only possible for short periods
Killed by desiccation to comparatively high moisture contents
Difficult to propagate, store, or maintain

Many larger seeds such as oak, horse chestnut, avocado, mango

Question 12

Quiescence

Answer 12

seeds will germinate any time given favorable conditions

Question 13

Dormancy

Answer 13

seeds will not germinate until certain environmental or physiological requirements have been met (exogenous or endogenous)

Question 14

Exogenous

Answer 14

conditions outside embryo

physical - impermeable seed coat (scarification)

mechanical - hard seed coat or other structure (scarification to fix, acid)

chemical - chemical around embryo like citrus (can put in water)

Question 15

Endogenous

Answer 15

conditions within embryo

physiological - chemicals within embryo
morphological - immature embryo

Question 16

Stratification

Answer 16

Seed stratification is a process that involves treating seeds before planting to simulate the natural conditions they would experience in the soil over winter.

Question 17

Germination

Answer 17

Germination is the process by which a plant grows from a seed into a seedling. It’s the result of a seed being exposed to the right conditions, such as water, oxygen, and temperature.

conditions for germination: seed must be viable, must overcome dormancy requirements, must have appropriate conditions (water, temp, oxygen, light)

Question 18

Cotyledon

Answer 18

the first leaf or set of leaves that emerge from the seed of a flowering plant during germination. Cotyledons are part of the seed embryo and play a vital role in providing nutrients to the developing seedling before true leaves form and the plant begins photosynthesis.

Question 19

Radicle

Answer 19

Radicle is defined as the embryonic root of the plant, which develops into the future root of the plant. It is the first part of the embryo to develop into the root system of plants.

Question 20

Damping Off

Answer 20

a fungal disease that affects young seedlings, causing them to collapse and die shortly after emerging from the soil

Question 21

What do we propagate by seed?

Answer 21

mostly everything but cultivars are not propagated by seed

Question 22

Why propagate by seed?

Answer 22

to grow a bunch of plants. more economical. create hybrids

Question 23

Mono vs. dicotyledon

Answer 23

1cotyledon vs 2

Question 24

4 steps to seed propagation

Answer 24

1. harvesting & cleaning
2. storage
3. breaking seed dormancy
4. germination

Question 25

Harvesting

Answer 25

Signs of maturity: cone will open, fruit will open, color or texture or smell will change

Dehiscent: Harvest before fruits split; dry and collect seeds from opened pods or capsules. Timing is crucial to avoid seed loss.

Indehiscent: Manually extract seeds from intact fruits; thresh, crack, or rub to release seeds. Protect seeds during extraction.

Fleshy: Remove seeds from pulp; rinse, ferment (if needed), and dry before storage. Avoid leaving pulp on seeds to prevent decay.

Question 26

Fleshy Fruit

Answer 26

Definition: Fruits that remain soft, juicy, and often edible at maturity, with fleshy tissue surrounding the seeds.
Seed Dispersal: Often rely on animals eating the fruit and dispersing seeds through their droppings or movement.
Examples:

Berry: Tomato, grape, blueberry.
Drupe: Peach, cherry, olive (with a single hard seed or stone).
Pome: Apple, pear (with seeds in a core).
Hesperidium: Orange, lemon (a citrus fruit with segmented flesh).
Pepos: Watermelon, cucumber.

Question 27

Methods of testing seed viability

Answer 27

germination test, float test, cut test, tetrazolium test (TZ), consult viability table

Question 28

Why do seeds have dormancy?

Answer 28

ensure favorable conditions, dispersal, soil seed bank

Question 29

stages of germination

Answer 29

imbibation, lag phase, radicle protrusion, cotyledon / shoot emergence

Question 30

epigeal germination

Answer 30

a type of seed germination where the cotyledons, or seed leaves, emerge above the soil surface.

Question 31

hypogeal germination

Answer 31

a type of seed germination where the seed leaves, or cotyledons, remain underground while the plant grows.

Question 32

commercial seed production testing

Answer 32

seeds are tested for viability, purity, vigor, and health