3.2 Fruits & seeds

Question 1

State the meaning of the term, “fruit”

Answer 1

A structure that develops from the ovary after fertilisation

Fruit contains the seed

Question 2

State the meaning of the term, “seed”

Answer 2

A seed develops from the ovule after fertilisation

Seed contains the plant embryo

Question 3

State the function of a fruit

Answer 3

Distribution and protection of the seed

May impose dormancy

Question 4

State the function of a seed

Answer 4

Distribution and protection of the embryo

May impose dormancy

Gives rise to new plants

Question 5

Describe the means by which seeds are dispersed (4)

Answer 5

Wind (samaras (winged seeds), parachute, censer)

Water

Explosive

Animals (attachment, scatter-hoarding, frugivory)

Question 6

Describe the structure of a seed

Answer 6

Testa

Hilum

Micropyle

Endosperm

Embryo

Question 7

What does the Embryo consist of?

Answer 7

Plumule

Epicotyl

Cotyledons

Hypocotyl

Radicle

Funicle

Question 8

What is the testa?

Answer 8

The outer, protective coat of a seed.

Holds seed contents together.

Question 9

What is the hilum?

Answer 9

The attachment scar where the ovule was attached to the ovary

Question 10

What is the micropyle?

Answer 10

Small pore next to hilum – allows water and oxygen to enter seed to trigger germination

Question 11

What is the endosperm?

Answer 11

Starchy food reserve

Question 12

What is the embryo?

Answer 12

A young, developing plant inside a seed.

Question 13

Embryo: What is the plumule?

Answer 13

The embryonic shoot

Question 14

Embryo: What is the epicotyl?

Answer 14

The stretch of stem-like tissue above cotyledons

Question 15

Embryo: What is the cotyledon?

Answer 15

The seed leaf or leaves (dicots have two, monocots have one)

Storage of starch for the developing embryo.

Allows photosynthesis in epigeal germination.

Question 16

Embryo: What is the hypocotyl?

Answer 16

The short stretch of stem-like tissue below cotyledons

Question 17

Embryo: What is the radicle?

Answer 17

The embryonic root

Question 18

Embryo: What is the funicle

Answer 18

Connects the seed to the carpel wall

Question 19

What is epigeal germination?

Answer 19

Cotyledons appear above the ground.

The hypocotyl elongates and drags the cotyledons above the surface of the soil

These plants typically have smaller cotyledons so deploy true leaves sooner to start photosynthesis

Testa shrivels up underground

e.g. Phaseolus vulgaris (French bean)

Question 20

What is hypogeal germination?

Answer 20

Cotyledons remain below the ground.

(The epicotyl elongates and the cotyledons remain underground)

The cotyledons are typically large food stores that allow the plant to get a head start without photosynthesis

e.g. Vicia faba (Broad bean)

Question 21

Name TWO mechanisms by which seeds are dispersed by wind:

Answer 21

A blade or wing which spins like a “helicopter” - flutters and spins to the ground

Parachutes with feathery appendages (drift on wind currents)