A1: Plant Reproduction

Question 1

What are the two types of plant reproduction?

Answer 1

sexual and asexual reproduction

Question 2

Explain the life cycle of a plant.

Answer 2

1) germination
2) growing plant
3) flowering plant
4) pollination
5) fertilization
6) dispersal of seeds

Question 3

Explain asexual reproduction in plants.

Answer 3

VEGETATIVE GROWTH
- portion of plant is taken
- result: genetically identical progeny

Question 4

When is asexual reproduction in plants an advantage?

Answer 4

When the plant shows superior qualities.

Question 5

Why is asexual reproduction in plants a disadvantage?

Answer 5

Because there is no genetic variability –> crucial for the health of the plant as a species.

Question 6

What is sexual reproduction?

Answer 6

The production of sex gametes followed by their fusion and development into an embryo.

Question 7

Explain the plants reproductive organs. What two types are there?

Answer 7

Male reproductive organs:
STAMEN:
- fillament
- anther

Female reproductive organs:
CARPEL:
- stigma
- style
- ovary
- ovule (forms within ovary)

Question 8

What does pollination lead to?

Answer 8

the generation of a pollen tube:
- discharge of sperm
- fertilization of the egg
- formation of an embryo

Question 9

What is pollination?

Answer 9

The transfer of pollen from an anther to a stigma.

Question 10

What does the process of polination require?

Answer 10

pollinators

Question 11

What are “pollination syndromes”?

Answer 11

flower traits that attract different pollinators.

Question 12

What are some examples through which pollination can take place?

Answer 12

• wind
• water
• insect
• animal

Question 13

What is biotic pollination?

Answer 13

Pollination by organisms.
- ENTOMOPHILY: pollination by insects
- ZOOPHILY: pollination by animals

Question 14

How does the majority of pollination occur?

Answer 14

Through biotic pollination (80%).

Question 15

What is abiotic pollination?

Answer 15

Pollination by non-organism factors.
ANEMOPHILY: pollination by wind (98%)
HYDROPHYLY: pollination by water

Question 16

What is a pollinator?

Answer 16

The agent which moves the pollen.

Question 17

What is a pollenizer?

Answer 17

The plant that provides the pollen.

Question 18

What are the two ways for pollination to occur?

Answer 18

• cross pollination
• self pollination

Question 19

What factors prevent self fertilization? What do they insure?

Answer 19

RECOGNITION factors.
- ensure genetic variability
- acts as a plants immune system
- recognizes and rejects ‘self pollen’

DEVELOPMENT OF STAMENS AND CARPELS AT DIFFERENT TIMES.
- pin (female) vs thrum (male)

Question 20

What is meant by “self-incompatability”?

Answer 20

The ability of a plant to reject its own pollen and the pollen of closely related individuals.

Question 21

What are dioecious plants unable to do?

Answer 21

self fertilize.
- they only posess one type of reproductive structure on each individual plant.

Question 22

What is cross-pollination? What is its other name?

Answer 22

• occurs between a pollinator and an externam pollenizer,
• “SYNGAMY”
• pollen is delivered to a flower of a different plant

Question 23

What is self-pollination? What is its other name?

Answer 23

• pollen moves to th efemale part of the same flower or to another flower on the same plant.
• AUTOGAMY
• accomplish pollination without an external pollinator

Question 24

What is CLEISTOGAMY?

Answer 24

• autogamy pollination
• occurs inside the glower, before the flower opens

Question 25

What do humans do to prevent self-fertilization?

Answer 25

• remove anthers
• develop sterile male plants

Question 26

What is the proper name of:
- mature pollen
- embryo sacs

Answer 26

• mature pollen= MICROGAMETOPHYTES
• embryo sacs= MEGAGAMETOPHYTES

Question 27

What is a pollen grain?

Answer 27

• generative cell
• tube cell
• spore wall

meiosis 2 times + mitosis + cytokinesis

Question 28

Explain the development of a microgametophyte.

Answer 28

pollen mother cell goes through:
- meiosis 1
- meiosis 2
- cytokenesis

Question 29

What is the female gametophyte?

Answer 29

embryo sac

Question 30

Explain the development of a megagametophyte.

Answer 30

• meiosis 1
• meiosis 2
• mitosis
• cytokenesis

Question 31

What is the embryo sac composed of?

Answer 31

• three antipodal nuclei
• two polar nuclei
• 2 synergids
• 1 egg

Question 32

What type of fertilization occurs in plants?

Answer 32

double fertilization

Question 33

Explain double fertlization.

Answer 33

1) pollen lands on stigma
2) pollen tube extends towards the ovary (generative nucleus undergoes mitosis —> 2 sperms develop)
3) 2 sperms follow tube nucleus, enter ovule through the micropyle

4.1) one sperm fertilizes the egg (produces the zygote –> divides into the embryo)
4.2) second sperm fuses with the two polar nuclei –> forms a tripod nucleus (i the ovules center) –> ENDOSPERM (food storing tissue of the seed)

Question 34

What is the name of the “food storing tissue of the seed”?

Answer 34

endosperm

Question 35

What happens after double fertilization?

Answer 35

the ovule develops into the seed (embryo, endosperm and integuments).

Question 36

What does mitosis allow the plant to do?

Answer 36

• asymmetric mitotic division
• differentiates cells
• establishes the root-shoot axis

Question 37

What does the ovule ingrument become?

Answer 37

the seed coat

Question 38

What part of the plant becomes the fruit?

Answer 38

• tissues of the ovary (carpel)
• receptacle

Question 39

What does the ovule do in wind pollinated plants? (gymnosperms)

Answer 39

exudes sap to trap pollen.

Question 40

What are the two types of asexual reproduction of plants?

Answer 40

vegetative propagation:
- natural
- artificial

Question 41

Explain natural vegetative propagation.

Answer 41

growing of new plants from parts of a parent plant such as underground stems, roots and leaves.

Question 42

What are some examples of midified stems?

Answer 42

• bulb,
• tuber,
• corm,
• rhizome,
• stolons (runners).

Question 43

What is a bulb?

Answer 43

• short stem base with one or more bulbs enclosed in many fleshy leaves

eg. onion, lily, tulip

Question 44

What is a corm?

Answer 44

• thick stem base with scaly leaves at the nodes
• contains stored food

eg. gladiola, begonia

Question 45

What is a tuber?

Answer 45

• enlarged stem part
• stored food
• (the eyes of a potato are its nodes where buds and roots will develop)

eg. potato

Question 46

What is a rhizome?

Answer 46

• underground stem that grows horizontally near the soil surface
• roots and buds develop at nodes and grow into new plants

eg. ginger

Question 47

What is a stolon? Other name?

Answer 47

• runner
• stems grow horizontally above the ground
• when the node touches the ground, roots and leaves develop and a new plant grows.

eg. strawberry, bermuda

Question 48

What are storage roots?

Answer 48

roots which contain food

eg. carrots, radish, and sweet potato

Question 49

Explain artificial vegetative propagation.

Answer 49

• method of plant propagation
• conducted by people

Question 50

What are some examples of artificial vegetative propagation?

Answer 50

• cutting (produces new parts of a plant independent of the parent)
• grafting (a branch of a stem is cut from one plant and inserted into another allowing the plants to share food and water through their stems)
• layering (aerial stem is encouraged to grow roots while still attached to the parent plant, and then is removed and planted)
• budding (cutting a bud from one plant and attaching it to another (bud will attach to the other plant as it grows big))
• marcotting (air layering- bark of stem is removed, roots grow out of the stem)
• cloning (group of cells is cut from the mother plant and placed in an agar growth medium containing nutrients and auxins)

Question 51

What is the purpose of grafting?

Answer 51

• speed maturity
• provide strong stalk
• repair damaged trunk (no flow of nutients and water)