Answer:
The Features of Euglena are:
1. Euglena has chloroplasts that allow it to photosynthesize.
2. Primitive eye-spot which detects light.
3. Euglena lacks a cell wall.
Explanation:
Answer:
OH, H2O2 and O−2
Explanation:
Reactive oxygen species (ROS) can be defined as highly reactive chemical compounds formed from molecular oxygen (O2). ROS are generated as a normal product of cellular metabolism, and also as a response to different environmental/internal cellular stimuli (e.g., cytokines, xenobiotics, pathogenic invasion). For example, hydroxyl radicals (·OH) are a type of ROS generated in the mitochondria which are capable of inducing oxidative stress in different cells and also trigger chronic inflammation. Moreover, hydrogen peroxide (H2O2) molecules represent another type of ROS which are produced during the stereoselective deamination of amino acids, i.e., the building blocks of proteins. These molecules (H2O2) exhibit toxic effects on the cell (e.g., DNA damage). Finally, singlet oxygen (1O2) is an excited state of molecular oxygen (O2) that is generated during photosynthesis in the photosystem II (PSII) of chloroplasts.
The natural rate of extinction as assumed by science is about 5 species per year. Currently scientists estimate we are losing species at 1000-10000 times that rate, with multiple species disappearing every day. A note on this idea is that the average extinction rate gives an unrealistic depiction of nature when we consider the catastrophic extinction events that ended the dinosaurs and shaped the ice age.
Answer:
Air is essential for all organisms
