unit 2, topic 1 Flashcards
what is fibre
the tissue of plants stems, leaves, seeds or roots
how do humans use plants
humans use plants for clothing paper and building materials.
why are plants critical to the ecosystem
because they produce oxygen that most organisms need to live
because industries excess carbon dioxide and pollutants to the atmosphere what do plants use do to prevent this
they use carbon dioxide because they breathe in carbon dioxide and let out oxygen.
plants are the basis of most…
food webs
what are the three reasons why plants are important
- they provide shelter for countless animals.
- plants help clean and filter water and absorb it.
- the roots of the plants help help soil in place and prevent it from being washed or blown away.
How many trees does it take to absorb the carbon dioxide from a car driven for one hour?
it takes four large trees to absorb the excess carbon dioxide put into the atmosphere when a car is driven four one hour,
today 75 percent of the world’s food supply is based on seven major crops..
- wheat
- rice
- maize (corn.)
- potatoes
- barley
- cassava
- sorghum.`
silk is the most
expensive fibre in the world.
what are the three natural fibres we use
cotton, hemp, and flax
what are the two manufactured fibres
polyester or nylon
what is cotton?
cotton is a natural fibre that has been grown and used by humans for centuries. Cotton fibres come from the plant’s seed. The fibres are strong , flexible and gradually spiral that causes the strands to interlock when twisted
what is hemp
Hemp is the oldest cultivated plant in the world. Hemp has less negative effect on the environment than other sources of fibre do.
what is flax
Flax is a food and fibre crop that is grown in the northern, cooler regions of the world. Flax fibres are taken from the stem of a plant and are two to three times strong as those of cotton. Flax fibre is also used for making linen paper.
What does the common silkworm eat?
they eat the leaves of a mulberry tree that provide the stable food of the common silkworm