lecture 2 part1 Floral Biology and Pollination

Question 1

The agencies of pollination fall into two groups:

What does Abiotic agencies mean?

Answer 1

non biological effects such as wind, water, rain.

Question 2

What does Biotic agencies mean?

Answer 2

Biological effects such as Insects, birds, monkeys, small mammals (Bats, rats) and small reptiles (geckos), ants, water skaters.

Question 3

plants which use biotic pollinators the plants and animals have coadapted and these various adaptations are called?

Answer 3

Adaptive syndromes

Question 4

Define oligophilic plants

Answer 4

meaning they have very few species of visitors (Often only one).

Question 5

What plants are oligophilic common in?

Answer 5

This tends to be most common in flowers with relatively specialised shapes (flags, trumpets, tubes), rather than “unsophisticated” flower with cup, bell or brush shapes which often have many different pollinating species and termed polyphilic

Question 6

Remember as many of the major classes of pollination syndromes

Answer 6

Animal pollinated - Zoophily

nsect pollinated-Entomophily

Beetles - cantarophily

Flies- Myophiy

Bees - melittophily

Butterflies - psycophily

Moths - phalaenophily

Birds - Ornithophily

Bats - chireptonophily

Wind - Anemophily

Water - Hydrophily

Question 7

What kind of partner are plants during pollination during transaction?

Answer 7

passive partner

Question 8

There is sometimes exceptions to the passive partner rules. What are these exceptions?

Answer 8

These exceptions are not entirely confined to animal-pollinated species. There are also explosive dis-charges of pollen into the air by the anemophilous species Ricinus communis and Parietaria diffusa.

Question 9

What is probably the most ancient type of pollination?

Answer 9

Pollination by wind

Question 10

What plants flourished in the Carboniferous and Mezoic areas?

Answer 10

chiefly vascular gymnosperms.

Question 11

How do most gymnosperms pollinate?

Answer 11

all wind-pollinated

Question 12

What is the general appearance for wind pollinated plants?

Answer 12

generally small and inconspicuous, and possess none of the attractive attributes of entomophilous species, but are often only composed of the essential organs only.

Question 13

Wind pollinated species include?

Answer 13

Grasses and sedges, conifers and many temperate broadleaf trees species such as walnuts, oaks etc.

Question 14

What is the general appearance of a anemophilous follower?

Answer 14

The flower of anemophilous species are frequently small, drab and dull in colour because they don’t need to attract animal pollinators. They are arranged in catkins which are most often unisexual. The male catkins are often pendulous and their axes are flexible so they they can be easily shaken or swayed by the wind.

Question 15

The pollen of the anemophilous is often?

Answer 15

small and smooth-coated

Question 16

Anemophilous species produce far greater amounts of pollen than?

Answer 16

entomophilous species.

Question 17

What did Pohl estimate in relation between Mercurialis annua and Romex acetosa

Answer 17

Pohl estimated that a single plant of Mercurialis annua and Rumex acetosa produce respectively 1,352,000,000 and 393,000,000 pollen grains!!! (Needed because pollination is down to chance).

Question 18

What do Anemophilous flowers no possess?

Answer 18

nectaries

Question 19

Where are the few ovules in the Anemophilous flowers located?

Answer 19

few ovules in the ovary, two in juglands and Quercus, and one in Urtica, Parietaria, Ulmus, Betula and Myrica and the grasses

Question 20

What do wind pollinated tree species produce to increase the chances of successful pollination?

Answer 20

Often wind pollinated tree species in temperate climates such as hazel (Corylus avellana) produce their tiny flowers early in the year before they produce leaves, and as a result the wind is able to gather the pollen without hindrance and the grains don’t get trapped in the foliage so increasing the chances of successful pollination

Question 21

What happens when Angiosperms return to the water?

Answer 21

Angiosperms which have “returned to the water” show differing degrees of adaptation to their environment. The conservation of the flower, which makes it such a valuable organ in taxonomy, is now exhibited in an entirely different way.

Question 22

Eelgrass is an example of what angiosperm?

Answer 22

Eelgrass is an example of an angiosperm which bears totally submerged flowers in tropical oceans, the flowers of which use hydrophilous pollination.

Question 23

What do flowers of hydrophilous lack?

Answer 23

Flowers of hydrophilous species have no colour nectaries or scent since these are not required

Question 24

What does the floral envelope consist of?

Answer 24

Their floral envelope is small, often only consisting of a single whorl of sepals, in some cases even this is missing and the flower exists as a single naked stamen or ovary as in the submerged Star Worts, the Callitriches

Question 25

True hydrophily where the pollen is water-born only occurs in?

Answer 25

totally submerged aquatic species.

Question 26

Give examples of totally submerged aquatic species

Answer 26

The most studied examples are the marine perennials, the grass wracks, Zostera, Phyllospadix and Halophila

Question 27

it is only these species (marine perennials, the grass wracks, Zostera, Phyllospadix and Halophila) that?

Answer 27

pollen itself is modified to suit the environment. Zostera marina has separate inflorescences of male and female flowers enclosed in the base of a grass-like leaf.

Question 28

The male flower is a?

Answer 28

single sessile anther.

Question 29

Anther wall and the land plants both don't have?

Answer 29

no endothecium

Question 30

What happens when Anther wall and land plants endothecium mature?

Answer 30

when it is mature it dehises by absorbing water which causes the innermost cells to swell and burst the sac.

Question 31

What is the visual structure of a pollen grain?

Answer 31

The pollen grains are very long and thread-like in shape. They have no exine and are shed naked into the sea. They are non-motile and coil around the stigma of the female flowers if they drift against them.

Question 32

When was rain pollination recognised?

Answer 32

The significance of rain as a pollinating agency in certain angiosperms only recognised relatively recently (1950’s).

Question 33

How was the significance of rain as a pollinating agent discovered?

Answer 33

Hagerup (1950) reported that in the faroe islands (Danish group of islands in North sea) that flowers of the creeping Buttercup (Ranunculus repens) were wide open even on rainy days. In these islands the rainfall is very high, but is very gentle and frequent, and this climate is of great importance to the pollination biology of these species growing in this region.

Question 34

R.repens are common throughout?

Answer 34

R. repens is common throughout the U.K. and much of Northern Europe and is a typical entomophilous species its flowers have bright yellow petals, are scented, bear large amounts of pollen and also some nectar.

Question 35

How does rain pollination work on these plants?

Answer 35

Most of the petal area is glossy and water proof, but at the base of each petal there is a dull area with nectary hidden under a small flap. If a raindrop falls on the flower it dislodges pollen from the anthers on the glossy part of the petal and runs down it and is then held by the matt absorbent base. Each additional drop swirls the floating pollen around the corolla cup which may become filled with water to the level of the glossy parts.

Question 36

How does the location of the carpels effect the water that is held?

Answer 36

The location of the carpels is such that the water rises by capillarity between them and the pollen is deposited on the stigma. There is a leak of water through gaps between the bases of the petals so that just enough water is held in the cup as is necessary of pollination

Question 37

What are Biotic agencies used for in plants?

Answer 37

Other species of flowering plants adopt a different strategy. To reduce wastage of energy (oils, proteins in pollen) in production of the huge amounts of pollen produced by wind pollinated species, they use animal messengers to collect the pollen and deliver it directly to the stigma of other plants of the same species.

Question 38

Plants that produce many small, inconspicuous flowers with large feather stigmas are likely to be pollinated by: a) Birds b) Wind c) Bees d) Moths e) Bats

Answer 38

b)wind

Question 39

Insect pollinated flowers: a) Are usually not red because insects do not perceive red as a distinct colour b) Are often strongly scented because insects have a well-developed sense of smell c) Often have nectar guides to direct the insects to the pollen or nectar d) All of the above e) None of the above

Answer 39

d) all of the above

Question 40

``` The stamens are: The male reproductive organs Composed of anther and filament The female reproductive organs Both a and b Both a and c ```

Answer 40

d) Both a and b

Question 41

Pollination is: a) The joining of the egg cell with a sperm b) The transfer of pollen from anther to stigma c) The production of mature pollen in the anthers d) None of the above

Answer 41

b) the transfer of pollen from anther to stigma