Horticulture Exam 2

Explain Crossbreeding

Two plants reproduce through pollen reaching the female flower.

Explain Induced Mutagenesis

Using a physical of chemical technique to introduce a mutagen in a plant.

Explain polyploidy

Plants with an abnormal number of chromosomes that causes changes in genotypes.

Explain protoplast fusion

Taking a protoplast from two plants and combining them to produce new genotypes.

Explain transgenesis

Introducing foreign DNA from other species into another plants genome.

Explain genome editing

Altering a plants DNA to acquire a desired outcome.

Why have farmers and scientists been breeding plants?

To increase a plants yield, taste, health benefits, growth habits, and certain tolerances.

Explain the central dogma of biology

DNA is transcribed into mRNA which is then translated and adds amino acids together to create proteins.

Define distant hybridization

Breeding among different genera.

Define intraspecific

Breeding within the same species.

Define interspecific

Breeding between different species.

Define somatic hybridization

Using protoplasts to breed plants.

Which of the following includes intra- and interspecific plant breeding?
a) Crossbreeding
b) Genetically modified
c) Mutagenesis

a) Crossbreeding

What methods are used in crossbreeding?

1. Natural cross-pollination

2. Manual/artificial pollination

3. Protoplast fusion

What methods are used in mutagenesis?

1. Chemical mutagenesis

2. Physical mutagenesis

What methods are used for genetic modification?

1. Agrobacterium

2. Gene gun

3. CRISPR-Cas9

4. Protoplasts (PEG & electroporation)

Protoplast fusion bypasses what?

Sexual incompatibility.

For protoplasts the media must be isotonic, hypotonic, or hypertonic to the cell?

Hypertonic

What are the two ways to make protoplasts fuse?

1. Electroporation

2. PEG

How does polyploidy happen naturally?

Nondisjunction either during meiosis 1 or meiosis 2.

How can polyploidy happen artificially?

Using protoplast fusion.

What are pros and cons of mutagenesis?

Pros: Can find new genes

Cons: You can’t target a desired genetic change

What are the 3 examples of physical treatment of mutagenesis?

1. UV radiation

2. X-rays

3. Gamma rays

What is the function of guide RNA in CRISPR-Cas9?

To guide the cas9 endonuclease onto the desired DNA sequence.

What is the function of the cas9 enzyme?

Cuts DNA strands at precise locations.

Deep Water Culture.

Aeroponics

Drip method

NFT (Nutrient film technique)

Ebb & Flow

Wick system

Explain the gene gun technique

Gold is coated in DNA and then place into a burst disk which is then placed into a vacuum chamber to prevent air resistance. Plant material such as leaves are placed under this burst disk and then pressurized helium causes the disk to shoot the gold onto the plant material.

Explain electroporation

Cells and plasmids are mixed together, an electric pulse causes pores to form in the membrane, plasmids enter the cell through the pores, pores seal once the plasmids are inside.

Explain PEG

Precipitates plasmid DNA while excluding contaminants in a solution.

What is Agrobacterium tumefaciens?

A soil borne bacteria capable or transferring DNA into plant cells.

What attracts Agrobacterium tumefaciens toward the plant?

Chemical signals released from damaged plant cells (Phenolics).

What is the Ti plasmid?

Circular DNA found in agrobacterium that enables the bacteria to infect plants.

What are the vir genes?

Genes located on the Ti plasmid

What happens the to T-DNA?

A single strange of T-DNA is taken from the Ti plasmid and is directed into a plant cell.

What to cytokinin and auxins do?

Triggers rapid cell division and creates a gall tumor on the plant.

What is the opine gene?

Provides a source of carbon and nitrogen for the bacteria in return for giving its T-DNA.

Explain aquaponics?

Aquaponics is a particular form of hydroponics where a water tank full of fish is underneath water tank of plants with one pipe feeding in and out between both tanks. The fish waster fertilizes the plants and small plant debris feed the fish.

Explain pruning vs. thinning

Pruning: removing lateral branches

Thinning: removing some of the fruits to encourage remaining fruits to grow larger

What are ways to control carbon dioxide?

• Burners

• Liquid form

• Ventilation

What is the difference between light quantity, light duration, and light quality?

• light quantity: amount of photos

• light duration: photoperiod

• light quality: spectrum

What are the ways to control humidity?

• Heating & venting

• Dehumidifier

What does bon mean? What does sai mean?

Bon = a tree

Sai = in a tray

What are bonsai called in China?

Penjing

What is bonsai called in Vietnam?

Hon Non Bo

How to people make trees look old?

• Bending the branches downward

• Causing curvature in trunk and stems

• pinching