Carbon dioxide—\text {CO}_2CO
2
start text, C, O, end text, start subscript, 2, end subscript—from the atmosphere is taken up by photosynthetic organisms and used to make organic molecules, which travel through food chains. In the end, the carbon atoms are released as \text {CO}_2CO
2
start text, C, O, end text, start subscript, 2, end subscript in respiration.
Slow geological processes, including the formation of sedimentary rock and fossil fuels, contribute to the carbon cycle over long timescales.
Some human activities, such as burning of fossil fuels and deforestation, increase atmospheric \text{CO}_2CO
2
start text, C, O, end text, start subscript, 2, end subscript and affect Earth's climate and oceans.
<span>Selective breeding is the process of breeding plants and animals for particular traits.</span>
Answer:
B
Because since they always kill the trees they invade by smothering them.
Answer: Option B. core samples
Explanation: this is the only option that is not used for locating minerals
Answer:
Answer is option D.
Flowers contain parts for making seeds.
Explanation:
The part of the plant that is responsible for the sexual reproduction in plants is known as flowers. A flower is said to be complete if contains sepals, petals, stamens and pistil. If the flower lacks one or more structures, it is an incomplete flower.
A complete flower consists of a vegetative part and a reproductive part. The vegetative part contains petals (a bright coloured structure that attracts insects and birds) and sepals (a green coloured structure that protects rising buds and is usually found beneath the petals). The reproductive parts include stamen or androecium (male reproductive organ) and pistil (female reproductive organ). A flower may consists of only female parts or only male parts, or both.
Stamen contains two parts - anther, which produce and store the pollens (male gametes) and filament, which support the anther. Pistil contains three parts - stigma, which receives the pollen grains and style that connects stigma and the ovary, and ovary which contains a lot of ovules (female gametes) which forms the seed.
Flowers reproduce by pollination, a process in which the pollen are transferred to the stigma of another flower. A pollen tube emerges from the pollen grain and grows through the style and reaches an ovule inside the ovary. Then the nucleus of the pollen grain passes through the pollen tube and fuses with the nucleus of the ovule and this process is known as fertilisation. The fertilised ovules become seeds and the ovary transforms into the fruit. The seeds are dispersed through various methods and the embryo inside them will grow into adult plants.
