pg. 1
PLANTS - BIO 152 LATEST UPDATE 2024-2025 EXAM
QUESTIONS WITH CORRECT VERIFIED ANSWERS
(VERIFIED) RATED A+
What were the two distinct multicellular generations that land plants evolved to? -
ANSWER - 1: released sperm into a moist environment
2: dispersed offspring through the air
What is the pattern that still exists in all plants today? - ANSWER - Alternation generations, one haploid and one diploid
Chara coralline - ANSWER - Multicellular algae Entirely haploid cells
What was the life cycle of the green algal ancestors (ex. Chara coralline) of land plants?
- ANSWER - Production of gametes, eggs and sperm, by mitosis
Each egg is retained within a female reproductive organ & each spiral-shaped sperm is released into the water (n) Fertilization occurs when an egg and sperm fuse to form a diploid zygote (2n) The zygote undergoes meiosis to produce four haploid nuclei spores (n) --> only one survives Haploid cell develops into a new multicellular haploid individual (beginning of next generation)
Where does fertilization and dispersal take place in Chara? - ANSWER - Water
- / 4
pg. 2 Walls of zygotes - ANSWER - Survive during droughts because they have a tough outer wall made of sporopollenin
Sporopollenin - ANSWER - A durable polymer that covers exposed zygotes of charophyte algae and forms the walls of plant spores, preventing them from drying out.
- most stable biopolymer known,
- extremely decay resistant
- dehydration resistant
- UV protection
Sporopollenin is so decay resistant that scientists couldn't... - ANSWER - degrade it to figure out what it is made of
How would Chara's (green algal ancestor) life cycle fare on land (how does sperm move)? - ANSWER - Sperm (such as in mosses and fern) can swim on ground when surfaces are wet and distances are small
How is dispersing offspring a major problem faced by plants? - ANSWER - Without water to carry the zygote away, the parent and offspring would grow on top of one another and have to compete for resources.
When do the life cycles of land plants and green algae diverge? What happens in Chara vs in land plants? - ANSWER - After the fusion of egg and sperm give rise to a diploid zygote that their life cycles diverge.
Chara: zygote dispersed by water currents then undergoes meiosis as its first step when it begins to develop Plants: zygote does not undergo meiosis and it does not disperse. Instead, it repeatedly divides by mitosis to produce a new multicellular generation made of diploid cells (can be described as an embryo by is it surrounded by material plant)
What is the scientific name for plants and why? - ANSWER - Embryophyte 2 / 4
pg. 3 What do all land plants have? - ANSWER - Embryo, alternation of generations, cuticle
Angiosperms characteristics (number of species) - ANSWER - The most successful land plant group 300,000 species Ecologically dominant
Traits that define Angiosperms - ANSWER - Produces flowers Ovules/seeds enclosed in a sporophyll (carpel) Produce fruit Pollen tubes and double fertilization
Gametophyte dominant - ANSWER - Haploid gamete producing phase is the dominant generation
- sporophyte is reduced and is dependent on gametophyte for nutrition
- mosses
Sporophyte dominant - ANSWER - diploid is the dominant life stage, more evolved trait
- gametophyte is reduced and is dependent on sporophyte for nutrition
- vascular plants
Are Mosses and other nonvascular plants gametophyte or sporophyte dominant? - ANSWER - gametophyte dominant Sporophyte is reduced and is dependent on gametophyte for nutrition
Are ferns and other seedless vascular plants gametophyte or sporophyte dominant? - ANSWER - The two live independently of each other Gametophyte is reduced, independent (photosynthetic and free-living) Sporophyte is also independent
- / 4
pg. 4
Are seed plants (gymnosperms and angiosperms) gametophyte or sporophyte dominant? - ANSWER - Sporophyte dominant Gametophyte is reduced (usually microscopic), dependent on surrounding sporophyte tissue for nutrition.Because in all land plants the fertilized egg is retained and develops in place (in the mother plant).
What do the haploid products of meiosis develop into? - ANSWER - Spores
Spores - ANSWER - A reproductive cell capable of growing into a new individual without fusion with another cell.Means of dispersal through the wind
Sporocyst - ANSWER - Diploid multicellular generation in plants that produces spores.
Gametophyte - ANSWER - In plant alternation of generations, describes the haploid multicellular generation that produces gametes.
Bryophytes - ANSWER - An assemblage of gametophyte-dominant plants that also includes liverworts, mosses, and hornworts Alternates between haploid gamete-producing generation and a diploid spore-producing generation
Are bryophytes unisexual or bisexual? - ANSWER - Many are bisexual - the same individual can produce both male and female gametes
Where do bryophytes live? - ANSWER - tend to live in moist understories of forests
- / 4