Maandag - Raven

20 important questions on Maandag - Raven

What is the heart stage?

As the cotyledons develop in eudicots, the globular embryo gradually assumes a two-lobed form, or heart shape.

When does the torpede stage of embryo development occur?

As the cotyledons and axis elongate and the primary meristems extend along with them.

During early embroyogenesis, where does cell division take place? And where does the addition of new cells become restricted to when it develops further?

Throughout the young sporophyte. Later is is restricted to the apical meristems of the shoot and root.
  • Higher grades + faster learning
  • Never study anything twice
  • 100% sure, 100% understanding
Discover Study Smart

Where and what are apical meristems?

They are found at the e tips of all shoots and roots and consist of cells that are capable of repeated division.

Where does the shoot apical meristem arise in monocot embryos?

On 1 side of the cotyledon and it is completely surrounded by a sheathlike extension from the base of the cotyledon.

What is the function of the suspensors of angiosperm?

They support early development of the embryo proper by providing it with nutrients and growth regulators, particularly gibberellins.

It undergoes apoptosis at the same time as the torpede stage of development. So it is not present in the mature seed.

What is a plumule?

The first bud.

What is the embryonic axis below the cotyledon(s) called if a radicle cannot be distinguished?

The hypocotyl-root axis.

What is (the function of) the seed coat?

The outer coat of the seed, which develops from the integument of the ovule and provides protection for the embryo.

When do seeds enter the second phase of seed development and what is it called?

At the end of embryogenesis, when cell division in the mature embryo ceases. It is called the maturation phase.

What happens during the maturation phase in regards to nutrient flow and storage?

1. During embryogenesis, there is a continuous flow of nutrients from the parent plant tissues to the tissues of the ovule. It is during the seed maturation phase, however, that a massive buildup of food reserves (starch, storage proteins, oils) occurs in the endosperm, perisperm, or cotyledons of the developing seed.
2. During the maturation phase, the seed undergoes desiccation as it loses water (90 percent or more) to the surrounding environment.
3. Seed coat hardens

How does the seed remain viable for long periods of time?

As a result of desiccation, metabolism within the seed decreases to an almost imperceptible level.

What are the most important external factors that determine the germination of the seed?

1. Water
2. Oxygen
3. Temperature
(4. Light, for small seeds)

What factors can cause coat-imposed dormancy?

1.  impermeability of the seed coat to water or oxygen
2. rigidity of the seed coat, which prevents the embryonic root from penetrating the coat
3. prevention by the seed coat of the escape of growth inhibitors from the seed
4. the presence in the seed coat of inhibitors that can suppress growth of the embryo

Exhibited by conifers, most cereals, and several eudicots.

What is primary dormancy?

The dormancy acquired during seed maturation.  Seed released from the plant may be in the primary state or nondormant.

What is second dormancy?

Seeds that are no longer dormant but encounter unfacorable conditions for germination, may again enter a stage of dormancy.

What is the primary root / taproot?

The first root.

What are lateral roots?

Branch roots formed by the primary root.

Where does the root system of adult monocot plants form from?

Teh stem-borne roots, which arise at the nodes (the parts of the stem wehere the leaves are attached) an then produce lateral roots. The primary root in monocots is short-lived.

Where is the stored food found in the majority of monocot seeds?

In the endosperm.

The question on the page originate from the summary of the following study material:

  • A unique study and practice tool
  • Never study anything twice again
  • Get the grades you hope for
  • 100% sure, 100% understanding
Remember faster, study better. Scientifically proven.
Trustpilot Logo