Cell Structure

Cell Size and Scale Some cells are visible to the unaided eye The smallest objects that the unaided human eye can see are about 0.1 mm long. That means that under the right conditions, you might be able to see an amoeba proteus, a human egg, and a paramecium without using magnification. A magnifying glass can help you to see them more clearly, but they will still look tiny. Smaller cells are easily visible under a light microscope. To see anything smaller than 500 nm, you will need an electron microscope. Adenine The label on the nucleotide is not quite accurate. How can an X chromosome be nearly as big as the head of the sperm cell? No, this isn't a mistake. The X chromosome is shown here in a condensed state, as it would appear in a cell that's going through mitosis. A chromosome is made up of genetic material (one long piece of DNA) wrapped around structural support proteins (histones). Carbon The size of the carbon atom is based on its van der Waals radius.

Microorganisms Let's study the wee ones of the world known as the microbes or the microorganisms. If you spend your life studying them, you would be a microbiologist. These are the smallest of the small and the simplest of the simple. What makes a microbe? It took one invention to change the way we see the world of microbes - the microscope. We'll give the big overview on the variety of microorganisms here. They can be heterotrophic or autotrophic. They can be solitary or colonial. They can reproduce sexually or asexually. In the face of climate change and food insecurity, New Zealand considers lab-grown fruit | New Zealand In the face of growing food security concerns due to climate change, scientists in New Zealand are attempting to grow fruit tissue in labs. While work on lab-grown meat has made headlines in recent years, similar work on fruit is less common. Scientists at Plant & Food Research in the southern city of Christchurch are aiming to change that by growing fruit tissue from plant cells that they hope will one day taste, smell and feel like real fruit. “Here in New Zealand, we’re good at growing conventional horticultural crops,” said Dr Ben Schon, the lead scientist for the Food by Design program at the government-backed Plant & Food Research, “but looking into the future, there’s a lot of change coming in the world with population growth, increasing urbanisation and climate change.” The program aims to grow fruit tissue without the parts that are usually discarded like the core of the apple or the rind of an orange. The technology could also offset the food lost in weather events.

Plants If you're not a microbe and you're not an animal, you are probably a plant. There are about 300 thousand known species of plants. Because plants adapt so well to almost any climate, scientists needed a way to organize the hundreds of thousands of species. In the same way there is a system of classification for animals, there is also a system of classification for plants. There are two big biochemical processes on Earth: Photosynthesis and Respiration. Plants also have cell walls that are made of cellulose. Not only do you see plants everywhere in the real world, but they are also all over the scientific world. On a non-scientific level, farmers have been observing plants for thousands of years. National Botanic Garden (US Capitol Video)

Cell Function All cells have a purpose. If they don't do anything productive, they are not needed anymore. In the big picture, a cell's purpose is much more important than acting as small organizational pieces. They had their purpose long before they started working together in groups and building more advanced organisms. When alone, a cell's main purpose is to survive. Even if you were a single cell, you would have a purpose. In the same way that cells survive in different ways; all cells have different types and amounts of organelles. While they might have a purpose, more advanced cells have a difficult time surviving on their own.