Plant Breeding Exam 1

Front 1

Plant breeding

Back 1

the art and science of improving plants in relation to their economic use

Front 2

Gene

Back 2

a unit of DNA at a specific site on a chromosome which directs RNA in protein synthesis which results in the expression of some certain characteristic in a living thing

Front 3

Chromosome

Back 3

a structure that contains a strand of DNA and other proteins that holds the DNA molecules together

Front 4

chromatid

Back 4

Either of the two daughter strands of a replicated chromosome that are joined by a single centromere and separate during cell division to become individual chromosomes

Front 5

sister chromatids

Back 5

Two identical strands joined by a common centromere as a result of a chromosome that duplicated during the S phase of the cell cycle.

Front 6

Phenotype

Back 6

the visible physical part of an organism that is determined by genetics and the environment

Front 7

Genotype

Back 7

the genetic makeup of a plant

Front 8

Cell cycle

Back 8

the collective phases of a cell including G1 (gap 1), S (DNA replication), G2 (gap 2), and M (mitosis)

Front 9

Karyokinesis

Back 9

the division of the nucleus

Front 10

Cytokinesis

Back 10

division of the cytoplasm

Front 11

Mitosis

Back 11

cell division that results in identical cells with the same number of chromosomes as the original cell

Front 12

List the different phases of a miotic division and an event characterizing that phase.

Back 12

Prophase: chromosomes condense into coils, sister chromatids evident
Metaphase: chromosomes move to equitorial plate, chromosomes attach to the spindle fibers
Anaphase: spindle fibers begin to pull apart at either end of the cell, sister chromatids begin to separate
Telophase: nuclear membrane forms around each daughter nucleus and a cell plate forms between the 2 new cells

Front 13

Meiosis

Back 13

cell division that is associated only with sexual cells where the resulting four cells have half the number of chromosomes as the parent cell

Front 14

Reductional division

Back 14

the first step in meiosis where homologous pairs of chromosomes are separated and make two cells with half the number of chromosomes as the parent cell

Front 15

Equational division

Back 15

the second step of meiosis where the two cells resulting from reductional division are split again resulting in four cells with the same number of chromosomes

Front 16

List the different phases of the first half of meiotic division and name at least one major event in each phase.

Back 16

Prophase 1: DNA exchanged between homologous chromosomes (chromosomal crossover)
Metaphase 1: Chromsomes are paired and aligned by the spindle fibers at the equitorial plate
Anaphase 1: Spindle fibers contract and pull each homologous chromosome pair away from each other
Telophase 1: 2 nuclear envelope surround separate chromosomes

Front 17

List the different stages of the second half of meiosis and name at least one major event in each phase.

Back 17

Prophase 2: each dyad is composed of a pair of sister chromatids and are connected by a centromere
Metaphase 2: chromosomes line up at metacentric plaste
Anaphase 2: separation of the dyads into individual chromosomes
Telophase 2: nuclear envelopes form around each set of DNA and cytoplasm divides

Front 18

chiasma

Back 18

the site of crossing over

Front 19

recombination

Back 19

a new combination of alleles, the joining of DNA from different sources

Front 20

Sporophyte

Back 20

a structure that has doubled the amount of chromosomes (2N)

Front 21

Gametophyte

Back 21

a plant or phase of a plant that produces gametes

Front 22

Sporogenesis

Back 22

diploid sporophytes undergo meiosis and produce spores with half as many chromosomes

Front 23

Gametogenesis

Back 23

spores grown into haploid gametophytes which produce gametes capable of fertilization

Front 24

Endomitosis

Back 24

when chromosomes are replicated without dividing the cell nucleus

Front 25

binucleate and trinucleate pollens

Back 25

binucleate: pollen with 2 nuclei, store well and germinates well in vitro
trinucleate: pollen with 3 nuclei, does not store well, poor germination in vitro

Front 26

Pollen mother cell

Back 26

a cell that comes from the hypodermis of the pollen sac and through meiosis produces four cells that develop into pollen grains

Front 27

Megaspore mother cell

Back 27

a cell that produces four megaspores through meiosis

Front 28

outbreeding (outcrossing)

Back 28

when plants are pollinated by other plants' pollen and not their own

Front 29

Inbreeding (selfing)

Back 29

when plants are pollinated by their own pollen they produce

Front 30

Gynoecium

Back 30

the female reproductive organs; includes pistils comprosied of stigma, style, ovaries

Front 31

Androecium

Back 31

male reproductive organs; includes stamens

Front 32

monoecy

Back 32

having unisexual reproductive flowers of both sexes on the same plant

Front 33

dioecy

Back 33

male and female flowers are on different plants

Front 34

monocot

Back 34

a flowering plant that has one cotyledon in the seed

Front 35

dicot

Back 35

a flowering plant with 2 cotyledons in the seed

Front 36

determinate plants

Back 36

a terminal flower is produced and no further growth exceeds that terminal flower

Front 37

indeterminate plants

Back 37

when the main axis elongates indefinitely developing new flowers laterally as it grows

Front 38

cleistogamous

Back 38

self-pollination and fertilization by an unopened flower

Front 39

chasmogamous

Back 39

flower that opens to allow pollination

Front 40

protogynous

Back 40

stigma receptive but pollen not yet produced and given by the anthers of the same flower

Front 41

protandrous

Back 41

what a flower's anthers release pollen before the same flower's stigma are receptive

Front 42

self-sterility

Back 42

inability to set seed from self pollen

Front 43

self-incompatibility

Back 43

inability of a fertile hermaphrodite plant to produce zygotes from self-pollination

Front 44

apomixis

Back 44

production of seeds through process other than meiosis and fertilization

Front 45

Apospory

Back 45

embryo sac developed from somatic cells at various locations in the ovule (2N)

Front 46

diplospory

Back 46

embryo develops in embryo sacs developed from unreduced megaspore mother cell (2N)

Front 47

adventitious embrony

Back 47

embryo develops in somatic cells of the ovule, integuments, or ovary wall through mitotic division

Front 48

parthenogenesis

Back 48

haploid embry develops from reduced egg nucleus in embryo sac without fertilization (results in haploidy)

Front 49

Mendels 2 principles

Back 49

Principle of Segregation
Principle of Independent Assortment

Front 50

Principle of Segregation

Back 50

allele pairs separate during gamete formation and randomly unite at fertilization

Front 51

Principle of Indenpendent assortment

Back 51

allele pairs separate independently of one another