AL102 Ch 14

true

Approach grafting is used when two related plants tend not to form grafts very well by other means.

false

Autoclaves are used to produce autoploids.

true

Before genetic engineering was developed, the improvement of crops involved hybridization, polyploidy, and mutation.

true

Budding is a form of grafting widely used commercially.

true

Cuttings can be made from stems, roots, or leaves.

repeated inbreeding

Development of homozygous purebred strains is brought about by

samples of wild relatives and local populations (land races) of domesticated plants can be studied and stored for future incorporation into new breeds of crops

Gene banks are locations where _____________________.

it is the source of disease and pest resistance that can be bred into new crop varieties

Genetic diversity in wild relatives and local populations of cultivated plant species is critically important to plant breeders because _____________.

false

Genetic engineering involves the construction of new apical meristems.

true

Germplasm banks have been created across the world to preserve the genetic diversity of important crop plants.

false

Grafting techniques are of relatively recent origin, being first practiced in the 1800's.

false

High-yielding crops produced during the green revolution require less water and fertilizer than previously produced crops.

stock

In grafting, the rooted part is known as the

true

In the future, transformed plants may produce viruses that act as vaccines against viral diseases.

false

It is essential in grafting to have the bark of the stock and scion in close contact with one another.

false

It is of no particular importance which end of a cutting is inserted in the ground.

Viability of the seeds decreased over time.

Last year you purchased a packet of pepper seeds and planted half of them, most of which germinated. This year you planted the remaining pepper seeds under the same soil, temperature, and moisture conditions, but only a few seeds germinated. Reduced seed germination this year is best explained by which of the following?

self-pollinating

Many crops, such as wheat, rice and beans, are ___________________ and do not require a pollinating agent such as wind or animals.

pruning

Methods for improving existing varieties of crop plants do NOT include __________.

hybrid

Most modern crops are grown from ____________ seeds, which are produced by cross-breeding inbred lines.

true

Mutations can be induced by chemicals.

true

One advantage of genetic engineering over traditional plant breeding is the introduction of genes from very distantly related organisms.

loss of seed dispersal by wind, water, or animals

One of the first changes in domesticated plants was probably __________________.

false

Outcrossing involves repeated self-pollination.

10,000

People began to domesticate plants in the Near East approximately ______ years ago.

Greater seed production Larger seed size Faster germination rate

Plant breeders selected for which of the following traits in crop plants? Select all that apply.

accelerated evolution guided by humans who are selecting those features beneficial to them.

Plant breeding is ___________________.

true

Polyploidy is when flowering plants have more than two sets of chromosomes.

true

Protoplast fusion can only take place after the cell walls have been digested.

true

Repair enzymes link DNA fragments together.

true

Rhizomes, runners, and potato tubers can be used for asexual propagation by cutting them into sections with each section having a node.

Harvesting of seeds for commercial purposes are done at the same time and with the same equipment used for to harvest non-commercial crops.

Seeds to be sold for planting must produce vigorous and uniform plants. To insure their seeds meet these standards, commercial seed growers do all of the following EXCEPT

Increases propagation rate Prevents exposure to pathogens Requires less maintenance Takes less space for propagation

Select all advantages of micropropagation over other asexual propagation methods

The societies had spiritual reasons for growing plants. The societies needed to supplement their food supplies.

Select all potential reasons why hunter-gatherer societies shifted to agricultural ones.

true

Six plant species provide 80% of the calories consumed by humans worldwide.

cereal grains

The first domesticated crop plants were:

all of the above

The primary goals of plant-breeding programs are _____________________.

bridge grafting

The type of grafting best suited for saving a tree that has been girdled is ________________________. (Appendix 4)

false

Tip-layering and air-layering are nearly identical techniques.

all of the above

Tissue culture is used _______________.

herbicide resistance; insect resistance

Two common types of transgenic plants widely grown in North America have genes for _________ and/or _____________ incorporated in their genome.

true

When a stock has a considerably greater diameter than that of a scion, cleft grafting is the most commonly employed grafting method.

sunflower

______ is the only major crop that was domesticated in the present U.S.

transgenic plants

_____________ are plants with specific genes from other organisms (from viruses to humans) inserted into the genome.

alter them genetically to meet our needs

when people "domesticate" plants, we ___________________.

Align the scion and rootstock so that their vascular cambia touch.

A gardener is grafting an orange tree scion to a disease-resistant Citrus rootstock. He makes a diagonal cut at the bottom of the scion branch and at the top of the rootstock, roughly several inches above the soil line. What should he do next to successfully create the graft?

all the genes of all the individuals in a population.

A gene pool consists of

Carry out mass selection Create hybrids from inbred lines

A plant breeder wants to create a line of broccoli plants that has fewer leaves. Given that a broccoli plant cannot fertilize itself, which of the following methods should he use? Select all that apply.

perform pure-line selection

A plant breeder wants to create a line of eggplant plants whose fruit are less bitter than current varieties. Given that an eggplant plant can fertilize itself, which of the following methods should she use?

cuttings

A plant breeder wants to produce genetically identical copies of a rare rose bush. Which propagation method should she use?

true

A plant resulting from the fusion of two protoplasts from different species is called a somatic hybrid.