Ch 30 & 42 - Plant Reproduction

Question 1

Complete Flower

Answer 1

Has all 4 whorls

Question 2

Perfect

Answer 2

Has both male and female parts

Question 3

Reproduction differences between angiosperms or animals

Answer 3

Both male and female in same structure

Reproductive organs are not permanent parts of individual

Question 4

Pollen

Answer 4

Anther contain 4 microsporangia
Microsporangia produce microspore mothers (2n)
Mothers produce 4 hapolid (1n) microspores via meiosis
Microspore undergoes mitosis and becomes pollen
Pollen cell divides to form 2 sperm cells
Mature pollen is binucleate

Question 5

Embryo Sac Formation

Answer 5

Ovule contains diploid megapore mother cell
Mother undergoes meiosis to make 4 haploid megaspore
Only one survives
Produces 8 haploid nuclei arrarnged in groups of 2
Enclosed in 7 celled embryo sac

Question 6

Angiosperm Life Cycle

Answer 6

Embryo Sac: 8 haploid nuclei
Nucleus migrate towards center: polar nuclei
Cell walls form around other 3 nuclei
One cell becomes egg
Other cells become synergids
3 cells at other end become antipodals

Question 7

Pollination

Answer 7

mechanical transfer of pollen from anther to stigma
Develop pollen tube to reach embryo sac
Pollen tube reaches ovule, enters one of the synergids, releases two sperm cells

Question 8

Double fertilization

Answer 8

One sperm unites with egg to form diploid (2n) zygote

Sperm unites with the two polar nuclei to form triploid (3n) endosperm - provides nutrients

Question 9

Meristem

Answer 9

leading growing structure

Question 10

Phase Change

Answer 10

When plants change from juvenile to adult, and can begin flowering
Usually leaves change, etc

Question 11

Flowering Genes

Answer 11

EMF: prevents early flowering, found in Arabidopsis
LFY: overexpression of flowering gene, reduces juvenile length

Question 12

Flower Production Pathways

Answer 12

Light dependent
Temperature dependent
Gibberellin dependent
Autonomous

Question 13

Light Dependent Pathway

Answer 13

Also called Photoperiodid
Sensitive to amount of light received throughout day
Obligate: Sharp distinction in day length
Facultative: Day length doesn’t totally determine flowering

Question 14

Phytochromes & Cryptochromes

Answer 14

Chemicals of Light dependent pathways
CO turns on genes that express LFY
Phyto: regulates CO transcription
Cyroto: modulates Co protein, protects from degradation during day

Question 15

Temperature Dependent Pathway

Answer 15

Vernalization: period of chilling before flowering

Question 16

Gibberellin Dependent Pathway

Answer 16

Gibberellin binds to LFY promoters
Promotes flowering
Delays flowering if not enough present

Question 17

Autonomous Pathway

Answer 17

Doesn’t depend on external clues
Day-neutral plants can count and remember node location
Florally determined: Flower at specific node
Related to root development

Question 18

Pollination

Answer 18

Pollen placed on stigma
Self: pollen of anther pollinates stigma of same flower
Cross or Outcrossing: pollen of anther of one pollinates stigma of another flower

Question 19

Pollinators

Answer 19

Bees are most common pollinators
Flowers guide pollinators with UV designs
Flowers that attract:
butterflies: landing platforms
moths: white or pale and are heavily scented
birds: red
monkeys: orange and yellow
wind: small, green, odorless

Question 20

Self Pollinators

Answer 20

Small inconspicuous flower
Flower meant to catch pollen into stigma
Favored in stable environments
Offspring more uniform

Question 21

Outcrossing Promotion

Answer 21

Separate male and female by space
Separate by time - called dichogamous
Self incompatibility, blocked at S locus

Question 22

Asexual Reproduction

Answer 22

Mitosis
Genetically identical
Common in harsh environments
Used in agriculture
Apoximis: cloning of diploid embryo in ovule
Done by citrus, dandelion

Question 23

Asexual Reproduction Clone

Answer 23

Cloned from parts of adult
Above ground: runners or stolons
Below ground: rhizomes
Sprouts: suckers (apples, cherries)
Adventitious plantlets: develop on surface

Question 24

Protoplast

Answer 24

plant cell enclosed by plasma membrane
Cell division forms callus - aka group of stem cells
Tissue engineering for plants

Question 25

Plant Lifetimes

Answer 25

Perennial: indefinite number of growing seasons
Deciduous: Leaves fall at specific time
Evergreen: Leaves fall throughout year; never bare
Annual: die within one growing season. Usually herbaceous
Biennial: 2 year life cycles