Why are plants different?
Many plants grow very high, but others remain small Deciduous trees shed their leaves in autumn, but only a few s shed their needles. The roots of trees very deep in the ground, some grow mutually others remain the surface. even live in a Everything beneficial and interdependent relationship called plants are a does is so all the differences seen in species adaptations for environment. The plant made depending on its continues to live even after a plant dies, since it always reproduces before dying.
How are annual rings formed in trees?
When trees grow, they accumulate wooden fibres around their heartwood. These fibres are bright and porous in spring so that a lot of water can reach the fresh leaves through them. By autumn, they become darker and thicker so the tree becomes stable and resistant to frost in the winter rest period. This process forms a bright ring and a dark ring around the heartwood every year. If you count the dark rings of a horizontal cross section of the tree trunk, you can find out the age of the tree. In the tropics, where there are no distinct seasons, the trees do not develop any rings. They grow all round the year and do not have any rest period.
How do plants reproduce?
Plants reproduce in a variety of ways, Many species build side shoots from which new plants grow. like mosses and ferns reproduce with the help of ores, which are distributed by the wind and grow to become new plants. rants or the seed plants with male and female sexual organs have stamens with pollen and the stigma. The male pollen sticks to the stigma and is passed on to the egg cell in the ovary A fertilized egg ripens to become a fruit, which contains the seeds. The seeds can be dispersed widely through wind or through animals Filament who eat the fruits and discard the seeds.
How do roots help plants?
Roots absorb water and the dissolved nutrient salts from the soil. They also store the nutrients as a reserve that the plant can survive on, when the soil dries up. The roots also anchor the plant firmly in the soil to safeguard against uprooting due to wind and bad weather. Roots change shape and adapt depending on their environment. Shallow-rooted plants, such as spruces, can hold their ground even at places where the soil cover is very thin. Plants such as pine trees, whose tap root grows deep in the ground, are found at places where water is available at great depths inside the earth.
What is symbiosis?
Symbiosis is a phenomenon in which two living organisms live together in such a way that they are mutually beneficial to each other. For example, the colorful clown fish live in a symbiotic relationship with the sea anemones. The clown fish enjoy the protection of the nettle fibres of the sea anemone and the sea one survives on the left-over food of the fish. The lichens that live in association with a fungus and an alga are also good examples of symbiotic relationships (page 61). Through the close interaction between its symbiotic partners, the lichens are able to grow in places, where they could never have existed alone.
Why do deciduous trees shed their leaves in autumn,but conifers do not shed their needles?
Deciduous trees lose a lot of water through evaporation from their large and thin leaves. In summer, this does not pose a problem, since the roots soak in enough water from the soil. but in winter this is not possible because the soil is frozen, if the leaves are not shed before winter, the water will continue to evaporate and the plant will dry up. Moreover, the leaves can become brittie with frost and crack. Therefore, the deciduous trees shed their leaves as a precautionary measure. Incontrast, the needles of the conifers are leathery and small, and there is very little evaporation through them The needles are also frost-proof and stop their growth in winter.
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