Flowers

Question 1

What part of the life cycle happens in the ovary of angiosperms/female cone of gymnosperms?

Answer 1

The growth of the sporangium and the production of the spores. The spores grow into whatever remains of the gametophyte, which then produces gametes. Fertilization happens and creates an embryo

Question 2

What type of leaf did flowers originate from?

Answer 2

Sporophylls

Question 3

What type of leaf did the carpel originate from?

Answer 3

Megasporophylls

Question 4

What type of leaf did the anther originate from?

Answer 4

Microsporophylls

Question 5

What type of leaf did the sepals and petals originate from?

Answer 5

Vegetative leaves

Question 6

What type of leaf did gymnosperm cones originate from?

Answer 6

All sporophylls, but only either the microsporophyll that became the male cone or megasporophyll that became the female cone

Question 7

What is spiral phyllotaxy?

Answer 7

Flower pattern seen in some of the dicots. Resembles spiral clusters of sporophylls that got compressed into a flower

Question 8

What is a complete flower?

Answer 8

A flower with all 4 whorls

Question 9

What are the 4 whorls in a flower?

Answer 9

1. Calyx: all sepals
2. Corolla: all petals
3. Androecium: male reproductive parts
4. Gynoecium: female reproductive parts

Question 10

What is the calyx? What does it do?

Answer 10

All the sepals of a flower. It protects the developing flower but has been modified in some plants

Question 11

What is the corolla? What does it do?

Answer 11

All the petals of a flower. They’re usually brightly coloured and/or produce nectar to attract pollinators

Question 12

What are tepals? What do they do?

Answer 12

Sepals that look identical to the petals in a mature flower. They have the same function as the petals

Question 13

How are the petals and sepals modified in Lasiopetalum species?

Answer 13

Petals are reduced to just produce nectar, and the sepals have become larger and brightly coloured to attract the pollinators instead of the petals

Question 14

What are the 2 parts of the stamen? What type of leaf did each one originate from?

Answer 14

Anther and filaments. They both came from the microsporophylls, but the anthers came from the reproductive portions and the filaments came from the vegetative portions

Question 15

What happens inside the anther?

Answer 15

Microsporogenesis. The microsporocyte undergoes meiosis, which produces 4 haploid microspores. Each one germinates into the microgametophyte, which matures into pollen

Question 16

What is the difference between gymnosperm and angiosperm pollen?

Answer 16

Gymnosperm pollen has 3 cells instead of 2, it has the generative cell, the pollen tube, and the prothallial cell. Angiosperms only have the generative cell and the pollen tube

Question 17

What is the megasporangium in angiosperms?

Answer 17

The ovule

Question 18

What happens inside the carpels?

Answer 18

Megasporogenesis. The megasporocyte undergoes meiosis and produce 4 megaspores, but only 1 will develop further. That one undergoes 3 rounds of mitosis to 7 cells with a total of 8 nuclei among them

Question 19

What is the structure of the remains of the megagametophyte in angiosperms?

Answer 19

3 Antipodal cells at the top, one large cell with the polar nuclei in the middle, 2 synergids at the bottom on either side of the egg cell

Question 20

What do the antipodal cells do?

Answer 20

Organizes the other cells of the megagametophyte

Question 21

What do the polar nuclei do?

Answer 21

Form the endosperm with double fertilization

Question 22

What do the synergids do?

Answer 22

Guide the pollen tube to the egg cell

Question 23

How is megasporogenesis different in gymnosperms?

Answer 23

The megasporocyte still 4 megaspores where only 1 survives and develops. But that one develops into a proper megagametophyte in the female cone with archegonia

Question 24

Why is having the ovary enclosed in the carpal advantageous?

Answer 24

Lets the plant be selective about what pollen pollinates it. Only pollen from the correct species will be able to make the correct interactions with the stigma to germinate

Question 25

What are 6 modifications of flowers?

Answer 25

1. Fusion of sepals or petals into tubes
2. Fusion of stamen
3. Fusion of all reproductive structures in hibiscus
4. Column in orchids
5. Ray and disk flowers in Asteraceae
6. Reduction of certain flower parts in wind pollinated flowers

Question 26

How do Drakaea orchids get pollinated?

Answer 26

The labellum mimics a female wasp by secreting pheromones, so when a male wasp lands and tries to fly off with it, the labellum flings it back into the column and covers it in pollen

Question 27

What are bracts?

Answer 27

Vegetative leaves that are not part of the 4 whorls but can take over function of petals or sepals