chap 23

Question 1

What is a general definition for plants?

Answer 1

multicellular photosynthetic eukaryotes

Question 2

what are plants thought to have evolved from?

Answer 2

fresh water green algae

Question 3

All chloroplasts and all land plants are in the same clade and form a monophyletic group. What does this statement mean?

Answer 3

A monophyletic group includes a common ancestor and all of its descendant species. This means that charophytes and land plants have shared traits that place them in a monophyletic group

Question 4

What charophyte traits are also found in land plants?

Answer 4

• both have same mechanism for forming cell wall
• apical cells allow both to grow in length
• plasmodesmata provide means of communication between cells
• both retain and care for the zygote

Question 5

• refers to the life cycle of plants; life cycle has alternating gameyophyte and sporophyte generations
• sporophyte generation produces spores by meiosis; spore is haploid cell that will become the gameyophyte
• gameyophyte generation produces gametes that dude during fertilization to form a zygote which will undergo mitosis you become the sporophyte

Answer 5

Alteration of Generation

Question 6

What are some traits unique to land plants that involve alteration of generations?

Answer 6

• alteration of generation
• both embryo and zygote protected from drying out
• sporophyte produces sporangia
• sporangia produces spores
• spores grow into gameyophyte
• gameyophytes’ gametagia produce gametes

Question 7

What are some traits unique to land plants that don’t involve alternation of generation?

Answer 7

• vascular tissue is used to transport water and nutrition
• cuticle to provide barrier to water loss
• stomata to regulate water and gas exchange with the atmosphere
• apical tissue which allows the production of complex tissues and organs