Deck 14: Plant Breeding and Propagation

Question 1

Somatic hybrids can be formed from:

A) egg and sperm nuclei
B) egg and polar nuclei
C) 2 parenchyma cells from different plants
D) 2 parenchyma cells from the same plant
E) None of these answers are correct.

Answer 1

C

Question 2

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

A) 5,000
B) 10,000
C) 2,500
D) 20,000
E) 25,000

Answer 2

B

Question 3

When people "domesticate" plants, we ________.

A) harvest them from wild populations
B) plant them in greenhouses
C) tame them
D) alter them genetically to meet our needs
E) claim the land where populations are found and let them continue to grow there

Answer 3

D

Question 4

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

A) hybrid
B) open pollinated
C) asexual
D) artificial
E) heirloom

Question 5

The man known as the "father of the green revolution" was

A) Gregor Mendel.
B) Johnny Appleseed.
C) Gustav Johansen.
D) Luther Burbank.
E) Norman Borlaug.

Question 6

The primary goals of plant-breeding programs are ________.

A) improved yield
B) disease resistance
C) pest resistance
D) stress tolerance
E) All of these answers are correct.

Question 7

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

A) Hybrid plants
B) Polyploid plants
C) Somatic hybrid plants
D) Transgenic plants
E) Heirloom plants

Question 8

A gene pool consists of

A) a liquid suspension of plasmids.
B) DNA fragments that have been broken by restriction enzymes.
C) an aquatic environment inhabited by large numbers of mutant organisms.
D) all the genes of all the individuals in a population.
E) genetically engineered organisms.

Question 9

The first domesticated crop plants were:

A) cereal grains
B) potato
C) banana
D) tomato
E) apple

Question 10

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

A) cross-pollinating
B) outcrossing
C) open pollinated
D) not dependent on fertilization to produce fruits and seeds
E) self-pollinating

Question 11

Circular extrachromosomal pieces of DNA in bacteria are called

A) prions.
B) plasmids.
C) capsids.
D) chromosomes.
E) Both prions and capsids are correct.

Question 12

The process of gene "splicing" begins with

A) the breaking of linkages between adjacent nucleotides of plasmids.
B) unpairing nucleotides in linear strands.
C) linking DNA fragments with repair enzymes.
D) insertion of recombinant plasmids into bacterial cells.
E) isolation and purification of the foreign gene (DNA) that is to be cloned.

Question 13

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

A) Tobacco
B) Corn
C) Squash
D) Sunflower
E) Rice

Question 14

Development of homozygous purebred strains is brought about by

A) cross-pollinating individuals of the same species or variety.
B) artificially inducing the doubling of chromosome numbers.
C) repeated inbreeding.
D) crossing heterozygous varieties with one another.
E) All of these answers are correct.

Question 15

Methods to insert desirable genes into a target cell in the production of a transgenic plant includes the use a crown gall bacterium or ________.

A) explant
B) producing a somatic hybrid cell
C) using a particle gun that fires very small DNA-covered gold pellets into the target cell
D) cross pollination
E) grafting

Question 16

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

A) crop seeds should be variable
B) it is the source of disease and pest resistance that can be bred into new crop varieties
C) modern agriculture relies on low diversity in crop varieties
D) they are searching for new crop species to develop
E) they have been domesticating approximately one new crop species per year since 1900

Question 17

Recombinant plasmids are made by

A) machines called protein sequencers.
B) mixing large numbers of DNA segments with fragments of desired DNA.
C) isolating them from other plasmids.
D) joining two different plasmids with repair enzymes.
E) producing mutant bacteria with X-radiation.

Question 18

Plant breeding is ________.

A) accelerated evolution guided by humans who are selecting those features beneficial to them.
B) picking out the best products of natural selection
C) intended to increase genetic diversity of plants in populations
D) a field that just started with the development of molecular genetics
E) None of these answers are correct.

Question 19

Gene banks are locations where ________.

A) national agencies maintain stocks of the most common plants grown in that country
B) plant breeders can deposit the germplasm of their new hybrids and crop varieties
C) plant breeders can borrow germplasm
D) 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
E) patented seeds can be stored

Question 20

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

A) increased requirement for fertilizer
B) geographic distribution
C) loss of seed dispersal by wind, water, or animals
D) flower color
E) decrease in size, number of seeds or fruits, and nutritional quality

Question 21

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

Question 22

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

A) whip grafting.
B) splice grafting.
C) cleft grafting.
D) bridge grafting.
E) bud grafting.

Question 23

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

A) frost resistance; potato blight resistance
B) insect resistance; wheat rust resistance
C) herbicide resistance; insect resistance
D) antifreeze genes; seedless fruit production
E) No transgenic plants are grown in North America.

Question 24

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

A) use of mutant forms
B) hybridization
C) use of polyploids
D) pruning
E) tissue culture

Question 25

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

Question 26

Tissue culture is used ________.

A) to rapidly increase the number of orchids for commercial sale
B) to culture protoplasts and propagate somatic hybrids
C) to grow plants from transgenic experiments
D) to propagate desirable somatic mutants such as naval oranges or seedless grapes
E) All of these answers are correct.

Question 27

Mutations can be induced by chemicals.

Question 28

In grafting, the rooted part is known as the

A) scion.
B) interstock.
C) stock.
D) cambium.
E) inarch.

Question 29

Repair enzymes link DNA fragments together.

Question 30

Autoclaves are used to produce autoploids.

Question 31

Restriction enzymes squeeze DNA strands into narrow strips.

Question 32

Genetic engineering involves the construction of new apical meristems.

Question 33

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

A) Plants used for commercial seed production are isolated from fields of similar crops to prevent cross breeding.
B) Prior to planting, seeds may be dusted with fungicide to insure seedlings become established.
C) Soil moisture is monitored and the fields irrigated when needed.
D) Soil or the seeds to be planted may be augmented with beneficial soil bacteria to insure good plant nutrition.
E) Harvesting of seeds for commercial purposes are done at the same time and with the same equipment used for to harvest non-commercial crops.

Question 34

An heirloom variety has undergone inbreeding to create a genetically uniform variety.

Question 35

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

Question 36

Outcrossing involves repeated self-pollination.

Question 37

A plasmid is a small circular DNA fragment.

Question 38

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

Question 39

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

Question 40

Mericloning, the cloning of meristems, significantly reduces the length of time it takes for orchid plants to flower

Question 41

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

Question 42

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

Question 43

Budding is a form of grafting widely used commercially.

Question 44

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

Question 45

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

Question 46

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

Question 47

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

Question 48

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

Question 49

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

Question 50

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

Question 51

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

Question 52

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