Chapter 4 - Plant Genotype (PPT)

Question 1

Genetic Improvements

Answer 1

• facilitate harvest
• pest and disease resistance
• tolerance to environmental stresses
• better flowers/colors of flowers
• better flavor
• increased nutritional value

Question 2

DNA

Answer 2

genes that control an organism

Question 3

RNA

Answer 3

genetic material that makes proteins, using DNA as the template

Question 4

Mitosis

Answer 4

splitting a cell into 2 identical daughter cells

Question 5

Meiosis

Answer 5

formation of games with half the number of normal chromosomes

Question 6

Haploid (n)

Answer 6

half the number of normal chromosomes (single genes)

Question 7

Diploid (2n)

Answer 7

normal number of chromosomes (pairs)

Question 8

Triploid (3n)

Answer 8

an extra set of chromosomes (3 single per group)

Question 9

Tetraploid (4n)

Answer 9

two extra sets of chromosomes (4 single per group)

Question 10

Polyploidy

Answer 10

3n, 4n, 5n, 6n, 7n, 8n, 9n, etc. multiple chromosomes in sets
-makes more vigorous, productive plants

Question 11

Fertilization

Answer 11

-sperm nucleus from pollen unites with ovule in ovary to form embryo

Question 12

Double Fertilization

Answer 12

• only happens w/ Angiosperms

- second sperm nucleus from pollen unites with other tissues in the ovary to make endosperm (3n)

Question 13

Heritability

Answer 13

F1: first cross (hybrid)
F2: cross of two F1s

Question 14

Homozygous

Answer 14

both alleles are the same

Question 15

Heterozygous

Answer 15

each allele is different

Question 16

Cloning Plants

Answer 16

Propagated asexually (without fertilization) - no recombination of genes
-Done w/ cuttings, layering, grafting, or tissue culture

Question 17

Heterosis

Answer 17

• Hybrid vigor: increase in size or vigor over either of the parents
• Inbreeding depression: two many recessive alleles causes problems

Question 18

GMOs

Answer 18

-not common in horticultural crops at this point

Question 19

Cross-Fertilization

Answer 19

-Dioecy in plants helps with cross-fertilization or cross-breeding

Question 20

Cross-Fertilization Incompatibility

Answer 20

• some fruit trees cannot pollinate their own species
• pollinizer: different tree that can fertilize the first species
• pollinator: bee or insect that moves pollen around
• Almonds, plums, sweet cherries, pears, apples and hazelnuts all need a pollinator
• Benefit: ensures genetic variability for adaptation

Question 21

Cross-Fertilization Dichogamy

Answer 21

-Male and female parts develop at different times (forces cross-fertilization)

Question 22

Cross-Fertilization Xenia

Answer 22

• Corn
• Cross-fertilization has an immediate effect on the ears
• Separate types of corn by about 1 mile or by 2 weeks in time
• Varied fruit colors

Question 23

Resistance

Answer 23

• variation in gene pool can allow some individuals to be resistant to a pest/pathogen
• can select and multiply those genes
• GOOD
• Applying too strong of selection pressure can lead to resistance (insect resistant to a pesticide, weed resistant to an herbicide)
• BAD

-ROTATING MODES OF ACTION is KEY!!