Answer:
Chemical weathering
Explanation:
Caves are formed by the dissolution of limestone. Rainwater picks up carbon dioxide from the air and as it percolates through the soil, which turns into a weak acid. This slowly dissolves out the limestone along the joints, bedding planes and fractures, some of which become enlarged enough to form caves.
Chemical weathering involves the decomposition of rocks due to chemical reactions between minerals such as calcite with water and gases in the atmosphere (e.g. carbon dioxide and sulphur dioxide). The solution of soluble minerals is particularly important in limestone landscapes.
Solutional caves or karst caves are the most frequently occurring caves. Such caves form in rock that is soluble; most occur in limestone, but they can also form in other rocks including chalk, dolomite, marble, salt, and gypsum.
Essentially, water reacts with carbon-dioxide to form carbonic acid. It then seeps slowly through the roof of the cave, depositing calcium carbonate, which hardens and builds up over time to form a stalactite.
Answer:
The correct answer is "5-1-3-2-4".
Explanation:
Internalization of LDL particles into cells, is needed to form the intracellular vesicles known as endosomes. The order of events that allow for this process are:
5) LDL receptors migrate to the cell surface and cluster in clathrin-coated pits. Clathrin acts directing the receptors to the cell membrane region where endosomes are formed.
1) A combination of cholesterol and apolipoprotein binds to LDL receptors and becomes internalized as endocytotic vesicles. Once the receptors are in the proper cell membrane region, cholesterol and apolipoprotein are bound and internalized.
3) Several endocytotic vesicles fuse to form an endosome.
2) The environment of the endosome becomes acidic, which causes the LDL to dissociate from its receptor; additionally, the endosome fuses with a lysosome. LDL should be dissociated from its receptor since it is going to be degraded in the following step.
4) The LDL particle is degraded by the lysosome. This takes place after endocytosis, when LDL particles are transported into lysosomes once they are fused, cleaving the cholesterol esters into cholesterol and fatty acids.
The answer would be letter a
A all cells have the same number of chromosomes hope this helps!! and C
Answer:Plants use carbon dioxide to make food
Explanation: Carbon-dioxide plays a very important role in sustaining life on Earth.
Plants use carbon-dioxide and water for photosynthesis in presence of sunlight and chlorophyll to produce food and oxygen.
CO₂ + H₂O → O₂ + glucose (food)
This food is consumed by the animals and oxygen is used for respiration. Animals use energy from the food to do work and exhale back carbon-dioxide.
