Lab Quiz 3 (Lab 9: Angiosperms)

Question 1

(flowering plant life cycle)

How many cells are there in a pollen grain and what are their functions?

Answer 1

There are 2 cells in the pollen grain: the genera3ve cell which produces 2 sperm (male gametes) and the tube cell which produces the pollen tube.

Question 2

(flowering plant life cycle)

How many nuclei are in the mature female gametophyte?

Answer 2

There are 8 nuclei total in the mature female gametophyte: one in the egg, one in each of the 2 synergids, two in the central cell, and one in each of the 3 antipodals.

Question 3

(flowering plant life cycle)

What is the ploidy of the endosperm?

Answer 3

Once fertilized (second fertilization of double fertilization), the central cell becomes endosperm. Ploidy of the endosperm is triploid (3n) (two polar nuclei of central cell fuse with the nucleus of the sperm)

Question 4

Are the flowers you observed bisexual, male, or female? Explain your answer.

Answer 4

The flowers are bisexual, they have both male and female reproductive structures in the same flower

Question 5

If a plant species has male and female plants it is

Answer 5

dioecious (2 houses)

Question 6

If a species has separate male and female flowers on the same plant it is

Answer 6

monoecious (1 house)

Question 7

How are their flower parts modified?

Answer 7

Petals, sepals stamens and pistils have different sizes, shapes and colors to attract pollinators

Question 8

Are the flowers large or small?

Answer 8

Some are smaller, most are larger

Question 9

How might the pollinator affect the flower morphology?

Answer 9

In many cases, he flower parts are modified to attract specific types of pollinators.
Long-throated flowers are morphologically shaped to aWract hummingbirds, which insert their beack to find the nectar at the bottom, picking up pollen.
Flowers with flat “landing pad” surfaces are modified to aWract insects like bees, flies and buWerflies that can crawl around and pick up pollen.

Question 10

One of the most common inflorescences is the raceme, which has indeterminate growth.
What evidence is there of this trait?

Answer 10

Old flowers are found at the base of the raceme infloresence, and new flowers are found at the top near the apical meristem (where continuous growth and development of new flowers takes place).

Question 11

Another common inflorescence is the head or capitulum.

How does it differ from a raceme? Are all of the flowers the same?

Answer 11

The capitulum is different from a raceme in that there is a thickened stem tissue/receptacle that holds all of the flowers in a tight cluster. There are different flowers in the head: disc flowers and ray flowers

Question 12

(angiosperm structure (bean or pea))

What is the ploidy of each of the structures?

Answer 12

Embryo is 2n and seed coat is 2n

Question 13

(angiosperm structure (bean or pea))

Where is the endosperm?

Answer 13

It would be surrounding the embryo.

At the stage that you have seen it, though, the endosperm has been absorbed by the developing cotyledons.

Question 14

(view seeds)

How are they different?

Answer 14

They are different in shape, color, size and hardness of the seed coat

Question 15

Why are some seed coats very hard?

How could the seed coat lead to seed dormancy?

Answer 15

Some seed coats are very hard because the plants require specific environmental conditions in order to successfully germinate and survive.
Having a hard seed coat blocks out any germination triggers like water or temperature until the conditions are just right for the successful survival of the future seedling.

Question 16

(dispersal strategy)

For fleshy fruits,

Answer 16

dispersal strategy is to provide food for animals, which will carry the seeds away to another area either while eating the fruit or when excreting the seeds out in another area.
Fleshy fruits like the pome include an ovary and surrounding fleshy receptacle tissue.
Fleshy fruit like the berry contain fleshy ovary material.

Question 17

(dispersal strategy)

For dry dehiscent fruits,

Answer 17

opening along “seams” (lines of dehiscence) many times seeds are flung out away from the plant due to the force of the fruit opening when dry.

Question 18

(dispersal strategy)

For dry indehiscent fruits,

Answer 18

many are picked up by small animals such as mice and squirrels, which gnaw at the outer hard covering to get at the seeds inside.
Some seeds are dropped in this case, and sometimes the fruit is carried away and buried, and then forgotten.

Question 19

On display are pictures of the flowers of some basal angiosperms, including magnoliids (Magnolia and Liriodendron), water lilies (Nymphaea), and Laurales (Persea, avocado).
Examine the pictures and determine what traits they have in common.
How are they different?

Answer 19

Common traits: many reproductive parts. Differences: shapes and sizes, and even sexual strategies (synchronous dichogamy.)

Question 20

monocots:
- How many seed leaves do they have?
- Is there a radicle?
- If not, what types of roots are possessed by these seedlings?

Answer 20

• One
• Not anymore, it has been lost at this stage
• Adventitious

Question 21

eudicots:
- How many seed leaves do they have?
- Do the seedlings have a radicle?
- What type of root system do these plants have?

Answer 21

• Two
• Yes
• Taproot

Question 22

male gametophyte =

Answer 22

pollen grain

Question 23

female gametophyte =

Answer 23

“megametophyte” ovule