Nucleus- The nucleus is the control center of the cell.
Mopic The cell is the basic unit of a living organism. In multicellular organisms organisms with more than one cella collection of cells that work together to perform similar functions is called a tissue.
In the next higher level of organization, various tissues that perform coordinated functions form organs. Finally, organs that work together to perform general processes form body systems. Types of cells Multicellular organisms contain a vast array of highly specialized cells.
Plants contain root cells, leaf cells, and stem cells. Humans have skin cells, nerve cells, and sex cells. Each kind of cell is structured to perform a highly specialized function. Often, examining a cell's structure reveals much about its function in the organism.
For instance, certain cells in the small intestine have developed microvilli hairs that promote the absorption of foods. Nerve cells, or neurons, are another kind of specialized cell whose form reflects function. Nerve cells consist of a cell body and long attachments, called axons, that conduct nerve impulses.
Dendrites are shorter attachments that receive nerve impulses. Sensory cells are cells that detect information from the outside environment and transmit that information to the brain.
Sensory cells often have unusual shapes and structures that contribute to their function. The rod cells in the retina of the eye, for instance, look like no other cell in the human body. Shaped like a rod, these cells have a light-sensitive region that contains numerous disks.
Within each disk is embedded a special light-sensitive pigment that captures light. When the pigment receives light from the outside environment, nerve cells in the eye are triggered to send a nerve impulse in the brain.
In this way, humans are able to detect light. Cells, however, can also exist as single-celled organisms.
The organisms called protists, for instance, are single-celled organisms. Examples of protists include the microscopic organism called Paramecium and the single-celled alga called Chlamydomonas.
Two types of cells are recognized in living things: The word prokaryote literally means "before the nucleus. Most prokaryotic organisms are single-celled, such as bacteria and algae.
The term eukaryote means "true nucleus. An organelle is a small structure that performs a specific set of functions within the eukaryotic cell. These organelles are held together by membranes. In addition to their lack of a nucleus, prokaryotes also lack these distinct organelles.
The structure and function of cells The basic structure of all cells, whether prokaryote and eukaryote, is the same.The cell is the basic building block of living organisms. Bacteria and the parasite that causes malaria consist of single cells, while plants and animals are made up of trillions of cells.
Most cells are spherical or cube shaped but some are a range of different shapes (see diagram ). Most cells. Relative sizes and shapes of some xylem cell types: (a) conifer tracheid with circular bordered pits, (b) fiber tracheid with bordered pits, (c) libriform fiber with simple pitting, (d) vessel element with scalariform perforations and (e) vessel element with a simple perforation.
The structure of each type of human cell depends on what function it will perform in the body. A direct relationship exists between the size and shape of every cell and the tasks it needs to accomplish. DNA: DNA, organic chemical of complex molecular structure found in all prokaryotic and eukaryotic cells.
It codes genetic information for the transmission of inherited traits. The structure of DNA was described in , leading to further understanding of DNA replication and hereditary control of cellular activities. The Nerve Cell is also called a neuron, its shape and function is it has alot of surface area and is very thin so the diffusion of wastes, water, urea, and other wastes in and out of the blood.
in science, students’ facility with addressing these concepts and related topics at any particular grade level depends on their prior experience and instruction.