Biodiversity Part 3 Plants Properties that distinguish plants

Biodiversity Part: 3

Plants ﺍﻟﻨﺒﺎﺗﺎﺕ §Properties that distinguish plants from previous kingdoms: 1 - Plants have chlorophyll for photosynthesis. 2 - Plant reproduction features alternation of generations. 3 - Plants have dependent embryos. 4 - Plants have roots or root-like structures that anchor it and absorb water and nutrient from the soil. 5 - Plants have a waxy cuticle that covers the surface of leaves and stems, limiting water loss.

Plants ﺍﻟﻨﺒﺎﺗﺎﺕ §Two major groups of land plants : the nonvascular plants and the vascular plants. §Nonvascular plants lack conducting structures, true roots, leaves, or stems. § They have rhizoids ( )ﺍﺷﺒﺎﻩ ﺟﺬﻭﺭ that anchor the plant and bring water and nutrients into the plant body. § Body size is limited due to the lack of conducting tissues, and slow diffusion must distribute water and nutrients throughout the plant body.

Plants ﺍﻟﻨﺒﺎﺗﺎﺕ § Gametophyte generation ( )ﺍﻟﻄﻮﺭ ﺍﻟﻤﺸﻴﺠﻲ is the predominating stage in the life cycle of the plant while sporophyte generation ( ) ﺍﻟﻄﻮﺭ ﺍﻟﺒﻮﻏﻲ is short term. § The reproductive structures of nonvascular plants are protected. - For example, An adaptation to terrestrial life is their enclosed reproductive structures )ﺗﺮﺍﻛﻴﺒﻬﺎ ﺍﻟﺜﻜﺎﺛﺮﻳﺔ ( ﻣﻄﻮﻗﺔ , which prevent the gametes from drying out. § Nonvascular plants include hornworts, liverworts, and mosses.

Plants ﺍﻟﻨﺒﺎﺗﺎﺕ §Vascular plants have conducting vessels that also provide support. § The conducting cells of vascular plants are called vessels, which contain lignin that serve support and conducting functions. § They have true stems and leaves, and the soprophyte generation is the predominating stage while lifespan of the gametophyte is very short. § Vascular plants can grow tall ( )ﺗﺰﺩﺍﺩ ﻓﻲ ﺍﻟﻄﻮﻝ because of vessels that provide support to these structures as well as conducting of water and nutrients between the roots to the leaves. § There are two groups of vascular plants: the seedless vascular plants and the seed plants.

Plants ﺍﻟﻨﺒﺎﺗﺎﺕ §Seedless vascular plants : §Seedless plants reproduce by spores §Some seedless plants do not have any vascular tissue. §They typically live in wet, humid places §They include the spike mosses, horsetails, whisk ferns and Ferns.

Plants ﺍﻟﻨﺒﺎﺗﺎﺕ §Seed plants : §Their sizes are bigger and obvious compared to seedless plants. §Seed plants reproduce by seeds § They have vascular tissue. § They are grouped into two general types: 1 - Gymnosperms, which lack flowers (e. g. Pine and Juniper) 2 - Angiosperms, the flowering plants. (majority of plants such as oranges )

Task for Students §What are other differences between Gymnosperms and Angiosperms? ?