W9 Ch.32 Definitions

Question 1

Sporophyte

Answer 1

This refers to the diploid (having two sets of chromosomes) phase in the life cycle of a plant or alga that produces spores through meiosis. The sporophyte generation typically follows fertilization of gametes and produces haploid spores through meiosis. In simpler terms, it’s the stage of a plant’s life cycle where it produces spores

Question 2

Gametophyte

Answer 2

This refers to the haploid (having one set of chromosomes) phase in the life cycle of a plant or alga that produces gametes (sex cells) through mitosis. The gametophyte generation typically arises from a spore and produces gametes that fuse during fertilization to form the diploid sporophyte. In simpler terms, it’s the stage of a plant’s life cycle where it produces gametes

Question 3

Alternation of generations

Answer 3

This is a reproductive cycle found in plants and some algae where two distinct phases, the sporophyte and the gametophyte, alternate in the life cycle. The sporophyte produces spores, which develop into gametophytes, which in turn produce gametes. Fertilization of gametes leads to the development of a new sporophyte generation, thus completing the cycle

Question 4

Sporangium

Answer 4

This is a structure in plants and some protists where spores are produced. It can be found in the sporophyte phase of the life cycle and typically contains sporocytes, which undergo meiosis to produce haploid spores

Question 5

Seed

Answer 5

A seed is the matured, fertilized ovule of a flowering plant. It contains the embryonic plant, stored food reserves (endosperm in many cases), and a protective seed coat. Seeds are a crucial reproductive adaptation that allows plants to disperse and survive in various environments

Question 6

Seed Coat

Answer 6

This is the outer covering of a seed. It provides protection for the embryo and the stored food reserves within the seed. The seed coat can vary in thickness, texture, and composition among different plant species

Question 7

Pollen Tube

Answer 7

This is a structure formed by a pollen grain during the process of pollination in flowering plants. It grows from the stigma of the flower down through the style and into the ovary, delivering sperm cells to the ovule for fertilization

Question 8

Dormancy

Answer 8

Dormancy is a period in an organism’s life cycle when growth, development, and physical activity are temporarily suspended. In plants, seeds often enter a period of dormancy to survive unfavorable environmental conditions until conditions become favorable for germination and growth

Question 9

Fruit

Answer 9

In flowering plants, a fruit is the mature ovary of a flower, typically containing seeds. Fruits develop from the fertilized ovary after pollination and serve to protect and aid in the dispersal of seeds

Question 10

Endosperm

Answer 10

This is a tissue found in the seeds of flowering plants. It is formed as a result of double fertilization and serves as a nutrient reserve for the developing embryo. Endosperm provides essential nutrients for the embryo’s growth and development

Question 11

Cotyledon

Answer 11

This is the embryonic leaf of a seed plant, usually containing the first seed leaves to emerge from the embryo. Cotyledons often function as nutrient storage organs and may become photosynthetic after germination

Question 12

Sepals

Answer 12

Sepals are the outermost parts of a flower, typically green and leaf-like in appearance. They enclose and protect the flower bud before it opens and often support the petals when the flower is in bloom

Question 13

Carpel

Answer 13

This is the female reproductive organ of a flower, typically consisting of an ovary, style, and stigma. The carpel encloses the ovules, which develop into seeds upon fertilization

Question 14

Pistil

Answer 14

This is the female reproductive organ of a flower, typically consisting of an ovary, style, and stigma. The carpel encloses the ovules, which develop into seeds upon fertilization

Question 15

Stigma

Answer 15

This is the receptive tip of the pistil where pollen lands and germinates during pollination. It is often sticky to help trap pollen grains

Question 16

Style

Answer 16

This is the slender stalk that connects the stigma to the ovary in a flower’s pistil. It serves as a conduit for pollen tubes to reach the ovules in the ovary

Question 17

Ovary

Answer 17

This is the enlarged basal portion of the pistil where ovules are produced and fertilization occurs. After fertilization, the ovary develops into a fruit containing seeds

Question 18

Pollen

Answer 18

Fine powdery substance containing the male gametes of seed plants, which produce sperm cells for fertilization of ovules

Question 19

Filament

Answer 19

The thin, elongated stalk that supports the anther in the stamen of a flower

Question 20

Stamen

Answer 20

The male reproductive organ of a flower, typically consisting of an anther and a filament

Question 21

Anther

Answer 21

The part of a stamen that contains the pollen, where pollen grains develop and are ultimately released

Question 22

Petal

Answer 22

The often colorful, modified leaf of a flower, which attracts pollinators and protects the reproductive organs

Question 23

Sepal

Answer 23

One of the individual units of the calyx, usually green, that protect the flower in bud and often support the petals when in bloom

Question 24

Whorl

Answer 24

A circular arrangement of similar parts, such as sepals, petals, or stamens, around the stem of a flower

Question 25

Selfing

Answer 25

When a flower is fertilized by its own pollen, leading to offspring with genetic material identical or very similar to the parent plant

Question 26

Outcrossing

Answer 26

When a flower is fertilized by pollen from a different plant, promoting genetic diversity in the offspring

Question 27

Duble Fertilization

Answer 27

A process unique to flowering plants where two sperm cells unite with two cells in the female gametophyte (embryo sac) to form the zygote and endosperm, respectively

Question 28

Pollen Tube

Answer 28

A structure that forms from a pollen grain upon germination and grows through the style towards the ovule, delivering the male gametes for fertilization

Question 29

Sexual Reproduction

Answer 29

The process by which offspring are produced by the fusion of gametes from two different individuals, resulting in genetic variation

Question 30

Asexual Reproduction

Answer 30

Reproduction that does not involve the fusion of gametes and results in offspring genetically identical to the parent plant

Question 31

Apomixis

Answer 31

A form of asexual reproduction in plants where seeds are produced without fertilization, resulting in offspring genetically identical to the parent plant

Question 32

Imbibition

Answer 32

The process by which seeds absorb water, leading to swelling and the initiation of germination

Question 33

Self-Incompatibility

Answer 33

A genetic mechanism in plants that prevents self-fertilization by rejecting pollen from the same plant or inhibiting its germination

Question 34

Totipotent

Answer 34

Describing a cell that has the ability to differentiate into any type of cell in the organism, including the ability to develop into a complete organism

Question 35

Inflorescence

Answer 35

The complete flower head of a plant, including its stalk or stem, typically containing multiple flowers

Question 36

Complete Flower

Answer 36

A flower that possesses all four floral organs: sepals, petals, stamens, and carpels. These flowers are capable of sexual reproduction and can potentially self-pollinate or cross-pollinate with other flowers

Question 37

Incomplete Flower

Answer 37

A flower lacking one or more of the four floral organs (sepals, petals, stamens, or carpels). Incomplete flowers may be missing either male or female reproductive structures

Question 38

Perfect Flower

Answer 38

A flower that contains both male (stamens) and female (carpels) reproductive organs. These flowers are capable of self-pollination if they possess functional stamens and carpels

Question 39

Imperfect Flower

Answer 39

flower that lacks either male (stamens) or female (carpels) reproductive organs. Imperfect flowers may be either male (staminate) or female (pistillate)

Question 40

Monoecious Species

Answer 40

A plant species that bears both male and female reproductive structures on the same individual. In monoecious species, both male and female flowers can be present on the same plant

Question 41

Dioecious Species

Answer 41

A plant species in which male and female reproductive structures are found on separate individuals. Dioecious plants require both male and female individuals for successful sexual reproduction

Question 42

Microspore

Answer 42

A small spore produced by a plant’s sporangium, which develops into a male gametophyte (pollen grain) in seed plants during the process of microgametogenesis

Question 43

Megaspore

Answer 43

A large spore produced by a plant’s sporangium, which develops into a female gametophyte (embryo sac) in seed plants during the process of megagametogenesis

Question 44

Embryo Sac

Answer 44

The female gametophyte in angiosperms, which develops from a megaspore and contains the egg cell and other cells necessary for fertilization and seed development

Question 45

Polar Nuclei

Answer 45

Two nuclei located in the central cell of the female gametophyte (embryo sac) in angiosperms. They are involved in the formation of endosperm after fertilization

Question 46

Pericarp

Answer 46

The thickened wall of a fruit, derived from the ovary wall, which surrounds the seeds. The pericarp may consist of several layers and protects the seeds and aids in seed dispersal

Question 47

Germination

Answer 47

The process by which a seed begins to grow and develop into a new plant. It involves the activation of metabolic processes within the seed, leading to the emergence of the embryo and its subsequent growth

Question 48

Synergid Cells

Answer 48

Cells located at the tip of the embryo sac in flowering plants. They play a role in guiding the pollen tube to the embryo sac during fertilization

Question 49

Generative Cell

Answer 49

A cell within a pollen grain that undergoes mitosis to produce two sperm cells in seed plants. These sperm cells are involved in double fertilization in angiosperms.

Question 50

Vegetative Cell

Answer 50

The larger of the two cells within a pollen grain in seed plants. It does not directly participate in fertilization but aids in the transport of the generative cell to the embryo sac during pollination.

Question 51

Diplostigmaty

Answer 51

A condition in flowers where each stamen has two stigma lobes. This condition can enhance cross-pollination by increasing the chances of pollen grains adhering to the stigma.