L12 Plant Physiology: Reproduction

Question 1

What are the two reproduction strategies in plants?

Answer 1

Sexual and Asexual.

Question 2

What is sexual reproduction in plants?

Answer 2

The pollen of one plant fertilises the stigma of another plant, thus combining the genes of two parents.

Question 3

What adaptations do insect-pollinated plants have to avoid self-pollination?

Answer 3

• Dioecious flowers (male and female parts on separate plants)
• Anthers ripen at a different time to the stigma (in monoecious flowers)
• Stigma and stamens arranged to ensure pollen transfer from previous flower

Question 4

How do wind-pollinated plants distribute their pollen?

Answer 4

They broadcast their pollen widely from anthers dangling outside the flower.

Question 5

What is a characteristic of the stigma in wind-pollinated plants?

Answer 5

Stigmas hang from other flowers of a separate plant.

Question 6

Fill in the blank: Dioecious flowers have _______ parts on separate plants.

Answer 6

male and female

Question 7

What is a key advantage of sexual reproduction?

Answer 7

All offspring are different from the parent

This genetic variation allows for better adaptation to changing environmental conditions.

Question 8

How does sexual reproduction benefit a population in terms of disease?

Answer 8

The entire population is less likely to be lost to disease

Genetic diversity can provide some individuals with resistance to certain diseases.

Question 9

What is a major disadvantage of sexual reproduction?

Answer 9

It is energy intensive

This includes the energy required to produce pollen, attractive flowers, and nectar.

Question 10

Why is producing lots of pollen a disadvantage of sexual reproduction?

Answer 10

It requires significant energy expenditure

This energy could be used for other growth or survival processes.

Question 11

What role do attractive flowers play in sexual reproduction?

Answer 11

They help attract pollinators

Attracting pollinators is essential for the fertilization process in many plants.

Question 12

What is asexual reproduction?

Answer 12

Self-fertilisation

Question 13

Why do many woodland plants rely on asexual reproduction?

Answer 13

Inefficient flower and seed production makes them less able to colonise new areas

Question 14

What are some methods of asexual reproduction?

Answer 14

• Suckers
• Tubers
• Runners/stolons
• Bulbs
• Corms

Question 15

How can propagation occur from broken stems?

Answer 15

Soak a broken stem in water before planting in compost to create a new plant from a ‘cutting’

Question 16

What is an advantage of asexual reproduction?

Answer 16

No need to find/grow near a mate

Question 17

What is another advantage of asexual reproduction?

Answer 17

Saves energy as less pollen and nectar is produced

Question 18

What is a disadvantage of asexual reproduction?

Answer 18

Lack of genetic variation

Question 19

What is another disadvantage of asexual reproduction?

Answer 19

Reduced ability to adapt to environmental changes

Question 20

What is a further disadvantage of asexual reproduction?

Answer 20

Localised distribution

Question 21

What is the natural limitation of seed distribution without modifications?

Answer 21

New plants could only develop around a parent plant due to seed drop.

This highlights the importance of seed dispersal mechanisms for plant propagation.

Question 22

What is one modification that allows seed distribution?

Answer 22

Wind distribution for dust-like seeds.

This method enables seeds to travel long distances through the air.

Question 23

What is an example of a sepal modification that aids in seed distribution?

Answer 23

Parachute structures like those of Dandelion.

These structures help seeds to be carried by the wind.

Question 24

How can seeds attach to animals for distribution?

Answer 24

Via sticky substances or hooks (burrs, e.g. Burdock).

This allows seeds to hitch a ride on animals and be transported to new locations.

Question 25

What adaptation allows seeds to float on water?

Answer 25

Trapped air or waxy waterproof layers. ## Footnote These adaptations help seeds disperse across water bodies.

Question 26

What mechanism allows for the ejection of seeds?

Answer 26

Spring-like structures. ## Footnote This can help seeds to be propelled away from the parent plant.

Question 27

How do animals contribute to seed distribution after fruit ingestion?

Answer 27

By evacuation of the seeds. ## Footnote This process allows seeds to be deposited in different locations, aiding in plant reproduction.

Question 28

Answer 28

* Seed coat – outer covering * Hilum - scar attachment * Micropyle - pore for water absorption * Cotyledon (Greek kotylēdōn cup-shaped hollow) – embryonic leaf or leaves. * Endosperm - nutritive tissue in embryo sac. * Embryo - part that will form seedling. following germination – radical (root) and plumule (shoot).

Question 29

What is the outer covering of a seed called?

Answer 29

Seed coat ## Footnote The seed coat protects the seed from physical damage and pathogens.

Question 30

What is the scar attachment on a seed known as?

Answer 30

Hilum ## Footnote The hilum is the point where the seed was attached to the ovary wall.

Question 31

What is the function of the micropyle in a seed?

Answer 31

Pore for water absorption ## Footnote The micropyle allows water to enter the seed for germination.

Question 32

What does the term cotyledon refer to?

Answer 32

Embryonic leaf or leaves ## Footnote Cotyledons are the first leaves that appear from a germinating seed.

Question 33

What is the nutritive tissue found in the embryo sac called?

Answer 33

Endosperm ## Footnote The endosperm provides essential nutrients to the developing embryo.

Question 34

What part of the seed will form the seedling after germination?

Answer 34

Embryo ## Footnote The embryo develops into the plant, with the radical forming the root and the plumule forming the shoot.

Question 35

Fill in the blank: The part of the embryo that will develop into the root is called the _______.

Answer 35

radical

Question 36

Fill in the blank: The part of the embryo that will develop into the shoot is known as the _______.

Answer 36

plumule

Question 37

What does the term 'hilum' refer to in seed anatomy?

Answer 37

Scar attachment ## Footnote The hilum is the point where the seed was attached to the ovary wall.

Question 38

What is the function of the micropyle in a seed?

Answer 38

Pore for water absorption ## Footnote The micropyle allows water to enter the seed during germination.

Question 39

Define cotyledon.

Answer 39

Embryonic leaf or leaves ## Footnote Cotyledons are the first leaves that appear from a germinating seed.

Question 40

What is the nutritive tissue found in the embryo sac called?

Answer 40

Endosperm ## Footnote The endosperm provides essential nutrients to the developing embryo.

Question 41

What part of the seed will form the seedling after germination?

Answer 41

Embryo ## Footnote The embryo consists of the radical (root) and plumule (shoot).

Question 42

List the requirements for germination.

Answer 42

* Moisture * Drainage * Correct temperature * Light or darkness * Protection from predators, drying, mould, excessive moisture ## Footnote These factors are crucial for the successful germination of seeds.

Question 43

List the Germination Stages of a seed

Answer 43

1. Water imbibed causing seed to swell. 1. Enzymes activated which convert starch to sugar. 1. Respiration accelerates providing energy. 1. Radicle (root) then Plumule (shoot) emerge. 1. Plumule emerges from soil and leaves develop.