Diversity of Flowering Plants

Question 1

what are the 3 parts of the generalized flower structure ?

Answer 1

1) pedicel
2) Receptacle
3) 4 whorls of modified flowers
- calyx (sepal - non sterile), corolla (petals), carpel, stamen

Question 2

what is an inflorescence? Name the parts of the inflorescence

Answer 2

• a group of flowers
  -pedicels connect the flowers to the peduncle (main stem)
• rachis: main axis of inflorescence

Question 3

What is the rachis?

Answer 3

• the axis point between pedicel and peduncle

Question 4

what are bracts ??

Answer 4

• a modified lead or specialized leaf, associated with a flower or inflorescence
• indirectly aid in reproduction (aid in pollination)

eg; poinsettias flowers are small, so has bright red showy bracts to attracts pollinators

Question 5

what are sepals?

Answer 5

• outer layer protect the floor bud before it opens
• frequency green
• form first and are lowest on the receptacle
• together known as the calyx

Question 6

what are petals?

Answer 6

• colourful modified leaves that attract pollinators
• form second, inside or above calyx on the receptacle
  -togeher known as the corolla

Question 7

what are stamens?

Answer 7

• pollen producing part of the flower
• together known as the androecium
• form their, inside or above perianth
• ach stamen has a long filament with an anther
• anther composed of two lobes and four pollen sacks
• pollen grains form within the pollen sacs

Question 8

How many lobes does na anther have?

Answer 8

• 2 lobes, 4 pollen sacs

Question 9

What are stamens together known as? what is the carpel together known as?

Answer 9

• anther: androecium
• carpel: androecium

Question 10

describe the carpel?

Answer 10

• ovule bearing or female part of the flower
• collectively known as the gynocium
• form last, inside or above andorecium
• flowers consist of one or more carpels : stigma, style, ovule

Question 11

what are carpels/pistils? what is a simple and compound pistil?

Answer 11

• carpels are megasporophyll
• a flower can consist of one or more carpels
• each carpel has a stigma style and ovary
• carpels can either be separate (apocarpous) or fused (syncarpous)

simple pistil: one carpel
compound pistil: two or more fused pistils

Question 12

what are the three types of fruit?

Answer 12

simple: a single carpel or several fused carpels
aggregate: multiple fused carpels from one flower
multiple: multiple flowers fuse together to form a fruit

Question 13

Describe complete, incomplete, bisexual, and unisexual flower parts

Answer 13

• complete: all four whorls
• incomplete: one or more whorl missing
• bisexual (perfect): has stamina and carpel
• unisexual (imperfect): missing one of the stamina or carpel

Question 14

Describe the symmetry of flowers

Answer 14

–> bilaterally symmetrical :
- symmetric split down the middle
–> radially symmetrical
- symmetric across all sides

Question 15

Which symmetry form is more advanced?

Answer 15

bilaterally symmetric and fewer parts and fused parts tend to be more advanced

Question 16

what are the 3 positions of the ovary?

Answer 16

• hypogynous : superior
• perigynous : semi-inferior
• epigynous : inferior (advanced)

Question 17

In which group did sporphylls first evolve?

Answer 17

• modified leaves
• first evolved in seedless vascular plants

Question 18

Describe angiosperm sporphylls. How are sepals and petals related?

Answer 18

• spooprhylls containing microsporangia - stamens
• sporophylls containing megasporangia - carpel

–> sepals and petals evolved as non fertile modified leaves associated with sporophylls

Question 19

describe the hypotheses for the evolution of carrels and stamens?

Answer 19

• stamens: upper part folded in, lower part became smaller
• carpels: folded inwards with top half coming out

Question 20

what is a biochemical classification?

Answer 20

• angiosperms classified based on diversity but also on biochemical classification: the presence or absence of alkaloids

Question 21

what are the 3 relevant families discussed for angiosperms

Answer 21

• grasses, orchids, sunflowers, legumes

Question 22

Describe the grass family

Answer 22

• monocots
• most grasses are wind pollinated (primitive)
• not showy, may be bisexual or unisexual
• fruit is a single seeded caryopsis: a grain with a single permanent cotyledon called a scutellum
• indehiscent

Question 23

Describe the fruit of the grass family

Answer 23

• fruit is single seeded caryopsis
• a grain with a single permanent cotyledon: scutellum

Question 24

Describe the orchid family

Answer 24

• monocots, largest family of angiosperms
• mostly found In tropics, bilaterally symmetrical
• herbaceous, many epiphytes
• large showy leaves
• dehiscent
• fruit is a capsule with no endosperm

Question 25

Describe the sunflower family

Answer 25

- largest family of dicots and second largest family of angiosperms - radial symmetric head - multiple flowers: ray and disc flowers - some species sepals modified to form bristles and scales = dandelions - fruit: cypsela; inferior ovary, single seed, indehiscent - great method of dispersal; dandelions have no dormancy period

Question 26

what is nyctinasty?

Answer 26

sleep movements in legumes (drops at night)

Question 27

describe the legume family

Answer 27

- 3rd family of angiosperms, dicots - flowers are bilaterally symmetrical - dehiscent fruit - embryos have little to no endosperm but they have fleshy cotledons - display nyctinasty (sleep movements) - relationship with N fixing bacteria

Question 28

What is a common N fixing bacteria?

Answer 28

rhixobium - plant provides bacteria with food, bacteria provides N to the plant

Question 29

what are the sizes of duckweed?

Answer 29

- some less than 1mm across - smallest flowering plant

Question 30

is self pollination or cross pollination more common in angiosperms?

Answer 30

both are common! - self pollination: transfer of pollen from anther of sam flower or from another flower on the same plant - reduce genetic variability, some may not be viable - cross pollination: transfer from pollen of a separate plant to the stigma - increases the number of genetic combinations in a plant, allows response to environmental change!

Question 31

why is cross pollination important?

Answer 31

- reduces the risk of pairing harmful alleles - allows for greater genetic combination - allows for response to environmental change!

Question 32

how might a monoecious plant avoid self pollination?

Answer 32

synchronize sex phases: prevent self pollination or promote it!

Question 33

what is a group of stamens called?

Answer 33

- androecium