Bio 123: PP8 Material Flashcards
What are the 5 derived traits in land plants?
1) alterations of generations
2) gametophytes
3) spores produced in sporangia
4) apical meristems
5) cuticle
What are diploid cells?
Cells that have their full set of chromosomes (have 2 sets).
How many body forms do plants take on?
Two different forms
Sporophyte stage
-(2n)
-the stage of the plant in which we typically see them
- are capable of undergoing meiosis at this stage
-multicellular diploid individual
What happens during meiosis of the sporangia?
During this stage, undifferentiated haploid spores are created.
Undifferentiated
Spores that are neither make or female
Haploid
Having 1 set of chromosomes
Name of a female gametophyte
Archegonium which holds the eggs
Name of the male gametophyte
Antheridium which holds the sperm
What is a zygote?
The first cell that is created after fertilization. It becomes a diploid at this point and has its full set of chromosomes.
What occurs with the zygotes formed from the male and female gametophytes?
The zygote undergoes rapid mitosis, making copies of itself, and leads to the development of the sporophyte.
What is a cuticle?
A waxy covering on the leaf that protects against insects, damage, and water loss.
Explain the alteration of generations in plants
-the diploid sporophyte produced haploid spores through meiosis
-Meiosis occurs in the sporangia and undifferentiated haploid cells are created.
-The haploid gametophyte produces male and female gametes through mitosis
-An egg and sperm gametes meet to create a fertilized diploid zygote.
-Zygote grows into a diploid sporophyte by mitosis and produces sporangia and the cycle is repeated.
When do land plants undergo mitosis?
After fertilization (diploid stage), after meiosis occurs in the sporophyte stage, after the gametophyte stage releases male/female cells.
What is a gametophyte?
-Haploid body form of a plant (n)
-Goal is to produce differentiated haploid gametes
-Gamete-producing generations which alternates with the diploid (2n) sporophyte.
What is a sporophyte?
The spore producing, diploid (2n) phase.
What is a sporangia?
The sporangia is a protected structure in which spores are produced.
What are apical meristems?
Regions of the plant body where cells undergo rapid mitotic division in order to allow the plant to grow. Seen in the tips of roots and the tips of stems
Where are apical meristems typically found?
At the tip of the plant because the plant grows upwards toward the sun and is competing for sun.
At the roots/base where plants can get the water and nutrients it needs.
What are nonvascular plants?
Plants that are lacking in vascular tissue and are completely reliant on aquatic vegetation in order to live. (bryophyta- liverworts, mosses, hornworts).
Where are Bryophyta typically found?
We will only see Bryophyta in aquatic environments
What is a unique characteristic of mosses?
They are the most ancient extant species on the planet
Seedless vascular plants
Do not have seeds and rely on water for reproduction. They have other tissue such as roots, leafs, true stems, etc. that allows them to be bigger than Bryophytes
Gymnosperms
Plants that have their seeds contained in cones
Angiosperms
Most successful group of plants on the planet today.
-Are capable of producing reproductive bodies that are known as flowers.
What are some characteristics of Bryophytes?
-Include 24,00 species of mosses, liverworts, and hornworts
-Are all nonvascular (lack vascular tissue) and do not grow taller than 8 inches
- Have rhizoids
-Live in moist habitats
-They are the earliest plants
What are rhizoids?
elongated cells or threadlike structures that absorb water and dissolved mineral ion. Typically live in aquatic environments
What are some characteristics of Mosses?
-Mosses can help regulate air pollution
-can help regulate climate change
-Mosses live to grow in acidic soil/acidic environments
-Acidic metabolic products hamper growth of bacterial and fungal decomposers which helps with the preservations of bodies and specimens
-There has been fossils found in environments with bryophytes
What is an indicator species?
What is an example?
Any set of species that are sensitive to environmental change/disruption.
Different amounts of lichens present can tell us how much sulfur dioxide is in the air.
What are peat bogs?
Moist organic remains of peat moss form peat bogs which helps store huge amounts of carbon. Damaged bogs dry out and release carbon dioxide into the atmosphere which accelerates climate change.
What is an example of a Moss?
Sphagnum also known as pete moss or petelands
What are some characteristics of Petelands?
-They have antiseptic properties, if you cut yourself you can put moss over a cut
-Can be turned into a fuel source,
-It is an important carbon reservoirs which helps regulate climate change
What are some characteristics of hornworts?
-accounts for 215 species worldwide
-Oxygen is lost faster (we see 5x more loss of oxygen) than places where moss is present.
-most are extinct
What are some characteristics of liverwarts?
-Accounts for 5-6 thousand species worldwide.
-Most are extinct
What is the first group of the kingdom plantae?
The Bryophyta- which are non vascular plants
What subgroups fall under Bryophyta?
Liverworts
Mosses
Hornwarts
What is the second group in the kingdom plantae?
Seedless vascular plants - which its reproduction must be aided by water since there is no seed present