Multicellular Organisms Flashcards
What does it mean for cells to specialize?
Specific cell types have a different structure to permit them to perform a specific function, this is called cell specialization. For example: the sperm cell has a flagellum. This is to help them travel to the ovum.
What is DNA?
DNA is a very long molecule that carries genetic information. the DNA in the nucleus consists of long, loosely packed strands called chromatin.
What are genes?
A gene is a small section of DNA on a chromosome, that code for a particular sequence of amino acids, to make a specific protein. It is the unit of heredity, and may be copied and passed on to the next generation
What is protein synthesis?
The cytoplasm contains a large collection of chemicals called amino acids. The coding DNA carries genetic information that cells or multicellular organisms use to produce a sequence of amino acids called a polypeptide. A polypeptide, or several polypeptide chains, fold to form a molecule called a protein. The production of a protein by cells using genetic information encoded in a specific gene.
What are the 5 steps of protein synthesis?
- Unwinding the DNA double helix exposes the gene
- RNA polymerase binds to the DNA (complementary base pairs)
- RNA polymerase makes the messenger RNA molecule (transcription)
- mRNA is transported out of the nucleus to ribosomes in cytoplasm
- Ribosomes attach to mRNA to assemble amino acids in codons (groups of 3) into a specific polypeptide (translation)
How do cells differentiate and express?
Cells in a multicellular organism develop differently to become specialized. All of the cells are genetically identical, or have the same genome. Different types of cells form in multicellular organisms because their cells use some genes to produce specific proteins, but not others. This is called gene expression.
What are the levels of organization within a multicellular organism?
Cell > Tissue > Organ > Organ System > Organism
Examples of different animal tissues
Nerve – involved in transmitting information, made of neurons
Muscle – is responsible for movement, made up of muscle cells called fibres
Connective – connect other tissues and organs together, eg. blood, fat and bone cells
Epithelial – covers the external body surface, lines organs and cavities and acts as a protective barrier against pathogens etc.
Reproductive – responsible for the production of sex cells
Examples of plant tissues
Dermal tissue – provides a protective cover
Vascular tissue – involved in transporting material
Ground tissue – store food energy, perform photosynthesis and provide structural support
Plant organs and systems
root – physically anchors and support the plant, absorb water and minerals from the soil, store sugars produced during photosynthesis
stem – holds plant upright, consists of vascular tissue that transports water and sugar between roots and leaves
leaves – collect sunlight and make sugars by photosynthesis
What is the cardiovascular system and its main organs?
The cardiovascular system consists of the heart, blood vessels, and blood. Its purpose is to transport nutrients, oxygen, and hormones to cells throughout the body and remove metabolic wastes. Protection of the body by white blood cells, antibodies, and complement proteins that circulate in the blood and defend the body against foreign microbes and toxins. Clotting mechanisms are also present that protect the body from blood loss after injuries.
What is the circulatory system and its main organs?
The circulatory system consists of the heart, lungs, blood, arteries, capillaries and veins. The circulatory system carries blood and dissolved substances to and from different places in the body. The heart has the job of pumping these things around the body. The heart pumps blood and substances around the body in tubes called blood vessels.
What is the digestive system and its main organs?
The digestive system consists of the mouth, oesophagus, stomach, small intestine, large intestine, liver, gallbladder, and pancreas. The purpose of the digestive system is to take in food, break it down into a useful form your cells can use (nutrients), and get those nutrients into your blood so that the circulatory system can take it to every cell in your body.
What is the endocrine system and its main organs?
The endocrine system consists of the thyroid, parathyroid, pancreas, ovary and the hypothalamus.
The endocrine system is made up of glands that produce and secrete hormones, chemical substances produced in the body that regulate the activity of cells or organs. These hormones regulate the body’s growth, metabolism, and sexual development and function.
What is the integumentary system and its main organs?
The integumentary system consists of the epidermis, dermis, hypodermis, associated glands, hair, and nails.
The integumentary system is the set of organs forming the outermost layer of an animal’s body. It comprises the skin and its appendages, acting as a physical barrier between the external environment and the internal environment that it serves to protect and maintain.
What is the lymphatic system and its main organs?
The lymphatic system consists of bone marrow, spleen, thymus gland, lymph nodes, and tonsils. The lymphatic system is our body’s ‘sewerage system’. It maintains fluid levels in our body tissues by removing all fluids that leak out of our blood vessels. The lymphatic system is important for the optimal functioning of our general and specific immune responses.
What is the muscular system and its main organs?
The skeletal system consists of the skeletal, smooth and cardiac muscles. The muscular system is composed of specialized cells called muscle fibres. Their predominant function is contractibility. Muscles, attached to bones or internal organs and blood vessels, are responsible for movement.
What is the nervous system and its main organs?
The nervous system consists of the brain, spinal cord, and sensory organs. The nervous system is the major controlling, regulatory, and communicating system in the body. It is the centre of all mental activity including thought, learning, and memory. It is in control of body’s internal environment to maintain ‘homeostasis’ (an example beings: keeping the body at an appropriate temperature)
