Biology Flashcards
What are the 8 characteristics that all living organisms share?
They need nutrition. They respire. They move. They excrete waste. They reproduce. They respond to their surroundings. They grow and develop. They can control their internal conditions.
Describe characteristics of plants.
Give two examples of a plant.
Plants are multicellular. They have chloroplasts which means they can photosynthesize. Their cells have cell walls, made of cellulose.
They store carbohydrates as sucrose or starch.
Cereals (maize) and herbaceous legumes (peas and beans).
Describe the characteristics of animals.
Give two examples of animals.
Animals are multicellular. They do not have chloroplasts, so they cannot photosynthesize. Their cells do not have cell walls they have membranes.
Most have some kind of nervous coordination.
Usually move. Store carbohydrates in the form of glycogen.
Insects and humans.
Describe Fungi. Give two examples
Some are single celled, others have a body called a mycelium, which is made of hyphae.
They can not photosynthesize.
Their cell walls are made of chitin.
Most feed by saprotrophic nutrition. They store carbohydrate as glycogen.
Yeast and mucor.
What is the process called where fungi get nutrition?
How does it work?
Saprotrophic nutrition.
Fungi secrete extracellular enzymes into an area outside their body to dissolve their food, so they can absorb the nutrients.
What are protoctists?
Give two examples.
Protoctists are single celled and microscopic organisms. Some have chloroplasts and are similar to plant cells. Others are like animal cells.
Two examples of protoctists are Chlorella and amoeba.
What are bacteria?
Give two examples.
Bacteria are single celled and microscopic. They don’t have a nucleus instead a circular chromosome of DNA. Most feed off other living organisms but some can photosynthesize.
Two examples are lactobacillus bulgaricus and Pneumococcus.
What are viruses?
Two examples.
Viruses are particles rather than cells, and a smaller than bacteria. They can only reproduce inside living cells. A virus is an example of a parasite, depending on other organisms to grow and reproduce. They infect all types of living organisms, they come in lots of different shapes and sizes. They do not have a cellular structure, instead they have a protein coat around some genetic material either DNA or RNA.
Two examples or influenza virus and tobacco mosaic virus.
also HIV
What are pathogens?
Give an example of a pathogen of protoctists, bacterium and viruses.
Pathogens are organisms that cause disease. They include some fungi, protoctists, and bacteria. Viruses are also pathogen’s.
And example of a pathogen in protoctists, are plasmodium, which causes malaria.
An example of a pathogen in bacterium,Is pneumococcus which causes pneumonia.
An example of a pathogen in viruses is influenza virus ,which causes the flu, and HIV which causes AIDS
What are enzymes?
Enzymes are biological catalysts produced by living things.
Give the definition of a catalyst
A catalyst is a substance which increases the speed of a reaction without being changed or used up in the reaction.
What is the definition of diffusion
Diffusion is the net movement of particles from an area of higher concentration to an area of lower concentration.
Give the definition of osmosis.
Osmosis is the net movement of water molecules across a partially permeable membrane from a region of higher water concentration to a region of lower water concentration.
Describe an experiment to investigate diffusion. (Phenolphthalein)
Diffusion: Agar jelly, Phenolphthalein and dilute acid. Agar jelly cubes with phenolphthalein and dilute sodium hydroxide. Place them in hydrochloric acid. Leave them for a while, they become colorless ,from pink, as the acid diffuses into the agar jelly and neutralizes they sodium hydroxide.
Describe an living system experiment investigating osmosis.
1) Potato cylinders.(living system): place Potato cylinders into identical cylinders, put different sugar solutions in them. One should be PURE water, another a very concentrated sugar solution.
Measure the lengths. If the potatoes have drawn in water they will have increased in length. If water was drawn out, they will have shrunk.
