Chapter 38

Question 1

Complete Flower

Answer 1

A flower that has all four basic floral organs

- sepals, petals, stamen, and carpels

Question 2

Inflorescence

Answer 2

A group of flowers tightly clustered together

Question 3

Angiosperm Lifecycle

Answer 3

• Megasporocyte undegoes meisis -> 4 megaspores, 3 mitotic divisions -> female gametophyte
• In the anther of a stamen, each microsporangium contains microsporocytes which produce 4 microspores. Each microspore develops into a pollen grain
• each pollen tube elongates through the style and deposits its two sperm once reaching an ovule. One fertilizes the egg, forming a zygote, and the other fertilized the central cell, forming the endosperm

The zygote forms an embryo and is packaged into a seed along with the endosperm.

When the seed develops it matures into a sporocyte

Question 4

Dormancy

Answer 4

A condition typified by extremely low metabolic rate and a suspension of growth and development

Question 5

Seed coat

Answer 5

A tough outer covering of a seed, formed from the outer coat of an ovule. In flowering plants, the seed coat encloses and protects the embryo and endosperm

Question 6

Hypocotyl

Answer 6

In an angiosperm embryo, the embryonic axis below the point of attachment of the cotyledons and above the radicle

Question 7

Epicotyl

Answer 7

In an angiosperm embryo, the embryonic axis above the point of attachment of the cotyledons and below the first pair of miniature leaves

Question 8

Coleoptile

Answer 8

The covering of the young shoot of the embryo of a grass seed

Question 9

Coleorhiza

Answer 9

The covering of the young root of the embryo of a grass seed

Question 10

Seed Germination

Answer 10

Starts with imbition
- the uptake of water by a seed or other strucure resulting in swelling.

This causes teh seed to expand and rupture its coat and triggers changes in the embryo to resume its growth

The first organ to emerge from a germinating seed is the radicle or the embryonic root
- the root sytem develops and anchors the seedling to soil and then the shoot tip emerges above ground

Question 11

Growth and Flowering

Answer 11

Most plant resources are used for primary and secondary growth of stems, roots, and leaves

Durin this stage, the plant grows as much as possible before flowing, the reproductive phase

Question 12

Pollen tube

Answer 12

A tube that forms after germination of the pollen grain and that functions in the delivery of sperm to the ovule

Question 13

Fruit

Answer 13

A mature ovary of a flower. The seeds develop from ovules and the ovary develops into a fruit

Aids in protecting enclosed seeds and in their disperal

Question 14

Simple fruits

Answer 14

A fruit derived from a single carpel or several fused carpels

Question 15

Aggregate fruit

Answer 15

Fruit derived from a single flower that has more than one carpel

Question 16

Multiple Fruit

Answer 16

A fruit derived from an entire inflorescence

Question 17

Acessory Fruits

Answer 17

A fruit or assemblage of fruits, in which the flesh parts are derived largely or entirely from tissues other than the ovary.

Question 18

Fragmentation

Answer 18

A means of asexual reproduction wherby a single parent breaks into parts that regenerate into whole individuals

Question 19

Apomixis

Answer 19

The ability of some plant species to reproduce asexually through seeds without fertilization by a male gamete

Question 20

Vegetative Reproduction

Answer 20

Asexual reproduction in plants based on the vegetative growth of stems, leaves, or roots

Question 21

Advantages and Disadvantages of Asexual Reproduction

Answer 21

Advantages

• no need for pollonation
• allows plants to pass on all of its genes to its progeny which is especially useful if a plant is very well adapted to its environment and the envionment is stable

Disadvantages
- uniformity of asexually produced plants puts them at a much greater risk of extinction if there is a catastrophic envionmental change

Question 22

Advantages and Disadvantages of Sexual Reproduction

Answer 22

Advantages

• Able to produce a large number of seeds
• greater variation in offspring and population which is helpful in unstable environments
• seeds facilitate the disperal of offsping to more distant locations
• seed dormancy allows growth to be suspended until environmental conditions become more favorable

Disadvantages

• seed germination is a precarious stage in a plants life
• resources consumed in flowering and fruiting

Question 23

Self-incompatibility

Answer 23

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

Question 24

Totipotent

Answer 24

Any cell that can divide and asexually generate a clone of the original organism

Question 25

Callus

Answer 25

A mass of dividing, undifferentiated cells growing at the site of a wound or in culture.

Question 26

Stock

Answer 26

The plant that provides the root system when making a graft

Question 27

Scion

Answer 27

The twig grafted onto the stock when making a graft