(harkess) Exam 1 plant growth and development

The 3 primary stages of embryogenesis

Globular, heart, Torpedo

The progressive pattern of development from a fertilized zygote to a mature seed is suggestive of the progressive and sequential activation of

genes

Which of the following is not a valuable function of the somatic embryogenesis

Seed production in plants

The suspensor can be removed from the developing embryo during the globular stage of embryogenesis with no effect on embryogenesis

FALSE

The concept exists that nearly all plant cells are totipotent. What does this mean?

All plants cells with a function nucleus are capable of giving rise to a whole plant.

As the embryo matures and seed start to ripen, the maturing seed's dry weight stays constant but the fresh weight declines. This is due to..

the maturing seed loosing water and dessicating to 10 to 15% moisture content

Somatic embryogenesis is the production of embryos, and eventually whole plants, from single vegetative cells. This confirms the theory that plant cells can set up their own polarity.

True

This is a shows the initial stages of embryogenesis where the nuclei are free floating i,e, no cell wall forms when the zygote nucleus divides. Which group of plants typically displays this type of development during embryogenesis

(round cell with random dots in middle)

gymnosperms

embryonic development is terminated at

maturation of the seed

Seeds that desiccate and become quiescent are known as ________ seed while those that hydrated at the time of seed shed and are unable to withstand desiccation are known as ______________ seed.

orthodox; unorthodox

Freshly harvested seeds of many plants will not germinate or germinate poorly. They require a period of warm, dry storage for a few weeks to a few months depending on species. This process is known as __________.

after ripening

Radicle emergence involves cell growth and rupture of the tissues surrounding the embryo, but typically does not involve ___________.

cellular division

What are the environmental factors that affect germination?

water, temperature, aeration, light

Seeds that have a specific requirement for light for germination are referred to as photoblastic seeds. These seeds require a brief exposure to red light while imbibed. What is the photoreceptor involved in this response?

phytochrome

During seed germination, imbibition of water occurs in a ___________ pattern.

triphasic

seeds can be viable for

a few weeks to hundreds of years.

What are phytohormone combinations which stimulated germination of the chart discussed in lecture

1)Gibberellins+Cytokinins+Abscisic Acid

2)Gibberellins+cytokinins

3)Gibberellins

What is the first general phase of germination?

emergence of the radicle

Breaking dormancy by exposing imbibed seeds to colds (2-5C) temperatures is a process called cold stratification. Cold stratification varies by species and ecotype and works by ______

1. leaching ABA and other germination inhibitors

2. giving rise to gibberellin-like substances

3. decreasing the embryo's sensitivity to ABA and other inhibitors

4. weakening the physical barrier (seed coat) to radicle protrusion by enzymes synthesized or activated by low temperatures

In seeds, rapid water uptake independent of metabolic activity occurs in phase ______ of seed germination.

1

The average size of a vegetative apical meristem is

100 to 250 picometers

The plant grows vegetatively the first year, initiates flowers the second year before flowering, setting seed, and dying the second year

Biannual growth

The plants grow and reach maturity producing flowers and seeds in one growing season

annual growth

The cycle of growth and flowering is repeated year after year with the plant surviving the winter by storage organs or with parenting buds

perennial growth

There is no set endpoint for plant size

indeterminate growth

when a shoot reaches a predetermined size the plant leases to get larger

determinate growth

Procambial cells normally give rise to vascular tissues, pericycle, and vascular cambium and would be found in which part of the apical meristem?

peripheral zone

Differentiation is the process whereby cells from a common origin become different

true

cells in the tunica layers primarily divide at right angles to the surface or

anticlinally

The time interval between the initiation of 2 successive leaves is called plastochron

true

Which of the following factors can contribute to the duration of two successive leaves is called a plastochron

true

Which of the following factors can contribute to the duration of plant growth

1. differences in species temperature requirements

2. flower initiation

day length

3. plant origin

4. genetic differences

5. endogenous controls

6. flushing (flushes of growth)

The cells in the area immediately above the youngest leaf primordial tend to be very small with a high _____ ratio

nucleus:cytoplasm

When the center of the apical meristem is isolated by making 3 to 4 deep vertical incisions leaving it attached to the rib meristem but severed from the peripheral zone and leaf primordia, it continues growing and in time will develop new leaf primordial and give rise to normal tissues of the shoot. this is evidence that the meristem is

autonomous

Determinate growth in plants can be regulated by terminal flowering as in many grasses or ____ in other plants

genetically

stigma, style, ovary, ovule

What four parts make up the pistil?

micropyle

A pore in the integuments of an ovule

anthers

male reproductive parts of a flower

pollen

A fine dust that contains the sperm of seed-producing plants

Scutellum (cotyledon)

Primary function is enzyme secretion for breaking down endosperm and transporting food to the developing seedling. Important source of oil and high-quality protein in cereal grains. The grass caryopsis has one cotyledon (scutellum), so grasses are known as monocotyledonous plants.

Heterotrophic

Organisms that obtain their nutrients or food from consuming other organisms.

autotrophic

make their own food

seed dormancy

ensures that the seed will germinate only in optimal conditions

types of seed dormancy

embryo dormancy

seed coat dormancy