Topic 17: Seed Plants - Angiosperms

Question 1

Angiosperms

Answer 1

Produce flowers and fruits, most diverse group of plants

Question 2

What are the two Shared Derived Traits of Angiosperms (3Fs)

Answer 2

Flowers, Double Fertilization, and Fruits

Question 3

What is the Angio Life Cycle?

Answer 3

Diploid sporophytes produce spores by meiosis, which grows into haploid gametophytes. These produce haploid gametes by mitosis, forming a diploid sporophyte through fertilization.

Question 4

What are flowers made for?

Answer 4

Sexual reproduction

Question 5

What are the four types of modified leaves of flowers?

Answer 5

1. Sepals
2. Petals
3. Stamens
4. Carpels

Question 6

Sepals

Answer 6

They are sterile and enclose/protect flowers.

Question 7

Petals

Answer 7

Sterile; are brightly coloured to attract pollinators.

Question 8

Stamens

Answer 8

Reproductive organ responsible for producing spores. Consists of a stalk (filament) topped by an anther containing pollen sacs that produce pollen. (Male)

Question 9

Pollen Sacs

Answer 9

Microsporangia

Question 10

Carpel

Answer 10

Reproductive organ responsible for producing the ovule. Consists of an ovary at the base, and a style leading up to the stigma, where pollen is received.

Question 11

Clusters of flowers

Answer 11

Inflorescences ex. sunflowers.

Question 12

Generative cell

Answer 12

develops into sperm nuclei

Question 13

Tube cell

Answer 13

forms the pollen tube.

Question 14

Polar nuclei

Answer 14

large central cell in female gametophytes contains two nuclei known as this.

Question 15

How many megaspores are produced?

Answer 15

4 but only one survives

Question 16

What happens when megaspores divide?

Answer 16

Produces 7-celled female gametophyte.

Question 17

Pollination

Answer 17

The transfer of pollen from an anther to a stigma.

Question 18

Double Fertilization

Answer 18

When the pollen tube discharges two sperm nuclie into the female gametophye one fertilizes the egg, while the other combines with two polar nuclei; forming a triploid cell.

Question 19

What happens to the triploid cell?

Answer 19

Develops into endosperm: a tissue rich in nutrients that nourish the embryo.

Question 20

2 Steps Post-Fertilization

Answer 20

1) Fertilized ovule develops into a seed
2) Ovary develops into a fruit enclosing the seeds

Question 21

What does the endosperm do?

Answer 21

Undergoes round of mitosis to generate food for the embryo.

Question 22

Fruit Development

Answer 22

The sporophyte ovary walls thicken and mature.

Question 23

What is the function of fruit?

Answer 23

1) to protect the seed when immature by being unappealing
2) to assist in seed dispersal by being appealing.

Question 24

What are the two categories of fruit?

Answer 24

Dry and Fleshy

Question 25

4 Adaptive Advantages of Angiosperm Fertilization

Answer 25

1. Endosperm develops after double fertilization (Conservation) 2. Fruit development is initiated by fertilization (efficiency) 3. Size reduction of female gametophyte (min. resources) 4. Rapid development of female development

Question 26

Modes of Pollination

Answer 26

Abiotic and Biotic

Question 27

Coevolution of Flowers and Pollinators

Answer 27

Species influence the evolution of interacting species in response to the selection pressures.

Question 28

Example of Coevolution

Answer 28

Darwin's Orchids and hawk-moth tongues.

Question 29

Sexual Reproduction

Answer 29

Meiosis and fertilization, yielding genetic diverse offspring.

Question 30

Asexual Reproduction

Answer 30

Generates genetically identical clones.

Question 31

Fragmentation

Answer 31

Where the parent plant separates into parts with each fragment developing into a new plant

Question 32

Apomixis

Answer 32

From a diploid cell without fertilization

Question 33

Advantage and Disadvantage of Asexual

Answer 33

Rapid growth, genetically vulnerable

Question 34

Advantage and Disadvantage of Sexual

Answer 34

Increase gene diversity, high risk in seeding stage.

Question 35

3 Ways to Prevent Self-Fertilization

Answer 35

1. Self Incompatibility 2. Incomplete Flowers ( separate flowers w/ separate genders) 3. Temporal/Spatial Separation

Question 36

When is self-fertilization beneficial?

Answer 36

When plants are in isolated environments, or pollinators are rare.

Question 37

When did angiosperms start dominating Earth?

Answer 37

In the Cretaceous period.

Question 38

Why did angiosperms begin to dominate?

Answer 38

- Developed modified xylem vessels - Rapid speciation due to coevolution - Rapid reproduction compared to gymno

Question 39

Amborella

Answer 39

Basal extant species of angiosperms

Question 40

Eudicots (dicots)

Answer 40

Contain an embryo w/ embryonic axis attached to two cotyledons

Question 41

Cotyledons

Answer 41

Means seedling leaves

Question 42

Monocot

Answer 42

have one cotyledon and a large endosperm