Thẻ ghi nhớ: Seedless Plants | Quizlet

What are characteristics needed to overcome to live on land?

Desiccation, Support (no buoyancy from water), Solar Radiation, Dispersal of sex cells (mobility and desiccation)

Desiccation

Drying out of cells/ organisms, can be harmful or fatal if they lack mechanisms to retain water.

What are the pros to living on land?

Lots of sunlight, CO2 is more available (no diffusion), and No predators (until land animals evolved)

What are the survival strategies of land plants?

Tolerance and Resistance

Tolerance Strategies of Land Plants

Combats the problem of water availability on land. Plants can completely dry out and then be restore when water is added. Mosses do this.

Resistance Strategies of Land Plants

Eventually evolved in land plants and is most common strategy now. Plants minimize water loss in order to survive dry environments (all environments on land can be dry environments)

What are the 4 Major Adaptations That led to terrestrial plant success?

Alternation of generations life cycle, apical meristems, waxy cuticle, cell walls/ liganin for support

What is alternation of generations?

Haplodiplontic life cycle that had a haploid phase and a diploid phase (haploid and diploid). All plants have this, looks different in different plants (homeosporous and heterosporous)

Haploid

Gametophyte (mitosis)

Diploid

Sporophyte (meiosis)

Homosporous

Plants that produce only one type of spore, gametophyte makes make and female gametes. Non-vascular plants

Heterosporous

Plants that makes 2 types of spores. Make = microspores, female = megaspores

Apical Meristem

A quickly dividing cap of undifferentiated cells at the shoot or root tips. Eventually become differentiated, kinda like a stem cell in animals.

Waxy Cuticle

Helped increase resistance by decreasing desiccation. Makes absorption of CO2 in the air difficult. The stomata regulates gas exchange in the leaves (CO2 in, O2 out, water vapor in and out)

What are the characteristics of support and structure of plants?

Without the support of water, plants needed internal and external structures to help them survive. Did this with the development of cell walls and the use of lignin

Plants remained short until strong structures and vascular tissues evolved.

Lignin

Polymer found in cell walls of plants, provides structural support, rigidity, and resistance against decay and pathogens.

What is the characteristics of having plants remain short in structure?

Provided more support. Allows water and minerals to move to all parts of the plant, eliminating the restriction of diffusion. Competition for sunlight on the ground drove the evolution of plant height.

What are the divisions of land plants

History with algae

Not all algae are considered plants. Brown and golden algae do not contain enough internal structures or perform similar function to plants. Green and red algae both contain chlorophyll an and fix carbon dioxide like plants, but are confusing because some species are unicellular or colonel. Charophytes are involved.

Charophytes

Group of green algae that is the only group of algae considered to be plants. They divide, grow, and contain cell structures very similar to green plants.

What are byrophtyes

Closes extant relatives to early land plants. Lack vascular tissue and lignin, but have alternation of generations and use photosynthesis. Have thalamus and rhizome structures. Divided into liverworts, hornworts, and mosses.

Extant

Refers to species, organisms, or other entities that are still living or currently in existence

Thallus

Leaf-like structures

Rhizomes

Root-like structures

Liverworts

Oldest bryophytes. Thallus shaped like the lobes on the liver hence the name.

Mosses

Most abundant group of bryophytes. Bioindicators and prevent soil erosion and weathering

Bioindicators

Sensitive to pollution and good biomonitors