Lecture 5 - Gathering Variability

Question 1

types of asexual reproduction

Answer 1

vegetative propagation and apomixis

Question 2

vegetative propagation

Answer 2

plant tissue other than seed used to produce a clone

Question 3

apomixis

Answer 3

plant embryos that develop from the megaspore mother cell without fertilization

Question 4

examples of vegetative propagation

Answer 4

tubers (potato), rhizomes (strawberry), bulbs and corms (many flowers)

Question 5

examples of apomixis

Answer 5

kentucky bluegrass, mango

Question 6

______ and _________ procedures are used by breeders/nurseries for propagation

Answer 6

cuttings, tissue culture

Question 7

genetic characteristics of asexual reproduction

Answer 7

• all progeny are identical to the parent plant (no genetic variability)
• maintain superior genotype (hybrid vigour fixed and continual supply of genotype)

Question 8

types of mutations

Answer 8

silent, missense, and non-sense

Question 9

silent mutation

Answer 9

same amino acid coded for so no change in phenotype

Question 10

missense mutation

Answer 10

change in amino acid, resulting in change in protein and phenotype

Question 11

non-sense mutation

Answer 11

change codon to a stop codon so it terminates the translation and changes the phenotype/lethal

Question 12

plant breeders only interested if mutation is:

Answer 12

• affect a plant’s ability to reproduce
• affects a plants end-use quality
• occurs in cells that produce gametes

Question 13

genome

Answer 13

each basic set of chromosomes characteristic of a species

Question 14

ploidy

Answer 14

the number of sets of the chromosomes

Question 15

haploid

Answer 15

1 set of chromosomes

Question 16

diploid

Answer 16

2 sets of chromosomes (2x)

Question 17

autopolyploid

Answer 17

multiple copies of the same genome in an individual (ex: alfalfa AAAA)

Question 18

allopolyploid

Answer 18

several different genomes within a single individual that acts like a diploid (ex: bread wheat AABBDD)

Question 19

advantages to polyploids

Answer 19

• increased vegetative vigour
• facilitates new gene combination that wouldn’t occur in a diploid
• possibility of recessive is much lower
• can combine genomes to create new species

Question 20

triploid

Answer 20

3 set of chromosomes

Question 21

how do triploids occur

Answer 21

-when an accidental unreduced diploid gamete pairs with a normal haploid one
-when you cross a diploid with a tetraploid

Question 22

how do you maintain triploids

Answer 22

seed propagation if it comes from a diploid x tetraploid
- vegetative propagation

Question 23

examples of triploids

Answer 23

bananas, seedless watermelon, some flowers

Question 24

types of gene duplication

Answer 24

-subfunctionalization
-neofunctionalization
-degeneration/gene loss