The reason why nost scientists thought that the first true cells formed on Earth were anaerobic is being shown in the second option :B. because there was no oxygen on early Earth. Paying attention to this fact scientists discovered that first cells were prokaryotes and greatest part of them created oxygen as a toxic by-product of their own metabolism which make them understand how the planet was provided with oxygen and made a conclusion that first cells were anaerobic.
<span>This research study would be a prospective cohort study. </span>
<span>In this study, the groups are different in some way, for example, a control group which received no treatment, a standard group who received a well-studied drug and a test group who received a new drug. These groups are followed over time and the outcome (such as curing a disease or alleviating symptoms) will be compared. </span>
The gene for beta-galactosides turns on
Answer:
Carbon cycle
Explanation:
Sunlight, photosynthesis and respiration is included in the carbon cycle and oxygen cycle. Oxygen cycle: The oxygen cycle is the cycle where in animal respiration atmospheric oxygen is converted to carbon dioxide and in photosynthesis it is regenerated by green plants.
Answer:
The correct order from smallest to largest are: Molecule, Cell, Tissue, Organ, Organ system and Organism.
Explanation:
- <u>Molecule</u> : They are very small particles or substance specially at both structural and cellular level. These are made up of two or more atoms which are held tightly by strong chemical bonds. The four important molecules of life are proteins, carbohydrates, lipids and nucleic acids.Without any of these molecules,survival of organisms and cells is very difficult. These molecules are very important in both the ways structurally as well as functionally.
- <u>Cell </u>:Cell is the most important, structural and functional unit of life. A cell is blessed with a capacity to carry out the main functions like nutrition, excretion and respiration. Cell is the important membrane bound unit that includes fundamental molecules of life of which all living organisms are made up of. A single cell is sometimes a complete organism in itself like bacterium or yeast. The four main types of cells are Epithelial cells, nerve cells,muscle cells and connective tissue cells.
- <u>Tissue</u> : A tissue is an assembly of similar cells and their extracellular matrix belongs to the same origin which combines together and carry out a specific function. Organs are the formation of functional groups of multiple tissues.There are four main types of tissue: muscle, epithelial, connective and nervous. Each is made up of special cells which are combined together depending on their structure and function. Example of connective tissue include fat & loose connective tissue
- <u>Organ </u> : An organ is a self contained cluster or sets of tissues which perform a specialised functions in the body.Two or more organs are working together in order to perform a special body functions forming an organ system also known as body system.When organs began to shut down, person will feel drowsy and starts losing consciousness. When the heart and lungs stop working body also dies. Heart rate changes. Pulse becomes fast or irregular.
- <u>Organ System:</u> An organ system is a set/ cluster of organs which are working together to perform a certain function in the body of an organism.The 11 organ systems of the body are integumentary, muscular, nervous, circulatory, lymphatic, respiratory, endocrine, urinary, reproductive and digestive
- <u>Organism</u>: It is a creature like plant, animal or single cellular life form in comparison to a living creature. They reacts to stimuli, reproduce grow and also play a main role in homeostasis. It can be virus, bacteria, protist, fungi or animal.