Bryopsida

Question 1

What are the key features of the leaf-like structures in mosses?

Answer 1

The leaf-like structures are nearly one cell thick, with a midrib running lengthwise. They lack petioles, lobes, or divisions and contain chloroplasts for photosynthesis.

Question 2

What is the function of rhizoids in mosses?

Answer 2

Rhizoids anchor the moss to substrates and assist in absorbing water and nutrients.

Question 3

How do mosses transport water in the absence of xylem?

Answer 3

Water moves through capillarity along the plant surface and central strand of hydroids.

Question 4

Define gametangia in mosses.

Answer 4

Gametangia are multicellular structures that produce gametes; they are located at the apices of leafy shoots.

Question 5

What are the two types of gametangia, and what do they produce?

Answer 5

Archegonia produce eggs, while antheridia produce sperm.

Question 6

Describe the structure of the archegonium in mosses.

Answer 6

The archegonium is cylindrical with a swollen base (venter) containing an egg and a neck with a canal for sperm entry.

Question 7

How is the sperm attracted to the egg in mosses?

Answer 7

The archegonium releases chemicals like sugars and proteins that attract the sperm.

Question 8

What is the role of the foot in moss sporophytes?

Answer 8

The foot anchors the sporophyte to the gametophyte and absorbs water and nutrients.

Question 9

Explain the role of the calyptra in mosses.

Answer 9

The calyptra is a protective cap that covers the developing sporophyte.

Question 10

Describe the structure and function of the seta in moss sporophytes.

Answer 10

The seta is a slender stalk that elevates the capsule, aiding in spore dispersal.

Question 11

What is the operculum, and how does it aid in spore dispersal?

Answer 11

The operculum is a lid on the capsule that detaches at maturity to release spores.

Question 12

What are peristome teeth, and how do they function?

Answer 12

Peristome teeth are membranous structures around the capsule rim that respond to humidity to regulate spore release.

Question 13

How do spores in mosses germinate into gametophytes?

Answer 13

Spores germinate into protonema, which develops buds that grow into mature gametophytes.

Question 14

What is a protonema, and how does it develop into a gametophyte?

Answer 14

A protonema is a filamentous structure that branches and produces buds, eventually forming a leafy gametophyte.

Question 15

Describe the asexual reproduction process in mosses.

Answer 15

Cells from various parts of the plant form protonema, which grows into a mature gametophyte.

Question 16

What environmental conditions are required for moss spore germination?

Answer 16

Spores germinate in damp, shaded, and nutrient-rich environments.

Question 17

How do mosses adapt to humid conditions for reproduction?

Answer 17

They rely on external water for sperm motility and fertilization.

Question 18

Define homothallic and heterothallic mosses with examples.

Answer 18

Homothallic mosses (e.g., Funaria) have male and female gametangia on the same plant, while heterothallic mosses (e.g., Polytrichum) have them on separate plants.

Question 19

How do moss sporophytes obtain nutrients?

Answer 19

Sporophytes depend on the gametophyte for water and nutrients through the foot.

Question 20

Explain the role of stomata on moss capsules.

Answer 20

Stomata facilitate gas exchange and remain open until the capsule ages.

Question 21

How do paraphyses assist in moss reproduction?

Answer 21

Paraphyses are hair-like structures that provide support and prevent desiccation of gametangia.

Question 22

What is the significance of chloroplasts in moss leaf cells?

Answer 22

Chloroplasts perform photosynthesis, providing energy for growth and reproduction.

Question 23

How does capillarity help water movement in mosses?

Answer 23

Capillarity allows water to move upwards through narrow spaces on the plant surface.

Question 24

Why are mosses considered non-vascular plants?

Answer 24

They lack true xylem and phloem for water and nutrient transport.

Question 25

How does the archegonium’s structure facilitate fertilization?

Answer 25

The neck canal guides sperm to the egg, aided by chemical signals from the archegonium.

Question 26

How do mosses contribute to ecological succession?

Answer 26

Mosses colonize bare surfaces, retain moisture, and create soil for other plants.

Question 27

Name three examples of mosses and their reproductive strategies.

Answer 27

Polytrichum (heterothallic), Funaria (homothallic), and Sphagnum (asexual spores).

Question 28

Compare the haploid and diploid phases in the moss life cycle.

Answer 28

The haploid gametophyte produces gametes, and the diploid sporophyte produces spores.

Question 29

What is the role of the capsule in moss sporophytes?

Answer 29

The capsule contains sporocytes that undergo meiosis to produce haploid spores.

Question 30

Describe how wind disperses moss spores in species lacking peristomes.

Answer 30

Wind blows spores out of capsules that split along specific lines.