EV HSC Biology 2 1st Chapter MCQ Question Answer. Animal diversity and Classification. Animal evolution began in the ocean over 600 million years ago with tiny creatures that probably do not resemble any living organism today. Since then, animals have evolved into a highly diverse kingdom. Although over one million extant (currently living) species of animals have been identified, scientists are continually discovering more species as they explore ecosystems around the world. The number of extant species is estimated to be between 3 and 30 million.
But what is an animal? While we can easily identify dogs, birds, fish, spiders, and worms as animals, other organisms, such as corals and sponges, are not as easy to classify. Animals vary in complexity—from sea sponges to crickets to chimpanzees—and scientists are faced with the difficult task of classifying them within a unified system. They must identify traits that are common to all animals as well as traits that can be used to distinguish among related groups of animals. The animal classification system characterizes animals based on their anatomy, morphology, evolutionary history, features of embryological development, and genetic makeup. This classification scheme is constantly developing as new information about species arises. Understanding and classifying the great variety of living species help us better understand how to conserve the diversity of life on earth.
EV HSC Biology 2 1st Chapter MCQ Question Answer. Animal diversity and Classification
EV HSC Biology 2nd Paper MCQ Question With Answer
Biology is the natural science that studies life and living organisms, including their physical structure, chemical processes, molecular interactions, physiological mechanisms, development, and evolution. Botany, also called plant science(s), plant biology or phytology, is the science of plant life and a branch of biology.
The fields within biology are further divided based on the scale at which organisms are studied and the methods used to study them: biochemistry examines the fundamental chemistry of life; molecular biology studies the complex interactions of systems of biological molecules; cellular biology examines the basic building block of all life, the cell; physiology examines the physical and chemical functions of the tissues and organ systems of an organism, and ecology examines how various organisms interrelate.
A botanist, plant scientist or phytologist is a scientist who specializes in this field. Zoology is the scientific study of animals. This discipline can include animal anatomy, physiology, biochemistry, genetics, evolution, ecology, behavior, and conservation.
The proper function of human bodies is dependent on smaller structures, or organs, such as the heart or lungs. The tiny cells that make up these organs actually contain within them smaller structures called organelles. These organelles help the cells to perform their jobs. In cancer, changes to these organelles can cause the individual cells and ultimately the entire organism to have serious problems. To get a better understanding of how cells work, we will now spend some time examining some of these subcellular structures.
The organelles that we will discuss are involved in the information flow within cells and in energy production. In addition, we will look at a structure that gives cells their shape and allows them to reproduce themselves. All of the organelles and processes to be discussed have direct relevance to cancer because these are the cellular structures/activities that become disturbed in the disease.
The image below shows two living mouse cells. The mitochondria are colored red and the nuclei (with brightly stained chromosomes) are colored blue. The green colored region near the nuclei of the cells represents the Golgi apparatus, an organelle involved in the processing and packaging of molecules within the cell.
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