Biology

• The nucleus is the control centre of the cell, containing DNA.
• Climate change is a term used to describe changes in the normal cycles of the Earth's climate that are attributed to human activity.
• Disturbances in the carbon cycle are central to these changes. There is an imbalance between the amount of carbon dioxide that is released into the atmosphere and the amount that is removed by natural processes like photosynthesis.
• Much of the excess carbon dioxide in the atmosphere, which results from activities like burning fossil fuels, is believed to dissolve in the ocean rather than accumulate in the atmosphere. What remains in the atmosphere, along with other gases, is responsible for a rise in global temperatures.
• Global warming, another term for the shift in global temperatures, occurs because of what is called the greenhouse effect, whereby increased concentrations of gases in the atmosphere absorb and radiate heat back to Earth. 
• Global warming is contributing to Climate change, which is causing significant changes to many of the Earth's ecosystems.
• The study of life is called biology. Because life takes on such a wide array of forms, scientists have devised a hierarchy of levels of biological organization.
• The basic units of matter are atoms; when they combine, they form molecules.
• Various molecules group together to form cells, the basic units of all living things.
• Some organisms, such as bacteria, are unicellular, while others, such as humans, are multicellular.
• Among multicellular organisms, groups of cells with similar functions make up tissues
• Groups of tissues combine to form organs, which work together to form organ systems
• These organ systems each carry out specific functions within an individual.
• We use the term science to refer to the systematic way in which we go about learning about the world around us.
• When this knowledge is applied to the interests of humans, we call it technology.
• Examples of technology include cell phones and pharmaceutical drugs, both of which could be created based on science and its investigations into observable phenomena.
• An organism makes another organism like itself. This is called reproduction.
• An organism goes through changes and stages to become an adult. The are called development stage.
• A long molecule contains the genetic instructions for the organization and metabolism of an organism. This is called DNA
• Changes in the genetic information are inheritable and are an important source of variation in the diversity of life. This is called mutation