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28 Cards in this Set
- Front
- Back
describe the structure of a monosaccharide |
A monosaccharide is 5 carbon atoms and an oxygen atom combining to form a ring |
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Name three polysaccharides |
Three polysaccharides include starch, cellulose and glycogen |
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Give one use of starch cellulose and glycogen |
Starch is used as the energy source in plant cells and as a food source for animals. Cellulose is used in plant cell walls. Glycogen is used as the energy store in animal cells. |
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Define the terms diet and balanced diet |
Diet is the quantity and quality of food eaten every day by an individual. A balanced diet has the quantity and quality of food needed to maintain good health. |
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Give three named examples of foods which can be eaten to obtain organic nutrients and inorganic nutrients |
Organic foods include chicken, bread and liver
Foods which contain inorganic nutrients include lettuce, liver and banana |
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Describe a meal which includes all the nutrients necessary for good health |
Rice, red beans, steamed pumpkin or carrots, chicken and orange juice |
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Define the terms physical digestion and chemical digestion |
Physical digestion is the mechanical breakdown of food into smaller pieces by the teeth. Chemical digestion is the breakdown of food by enzymes into soluble compounds. |
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Describe giving examples the role of enzymes in digestion |
Enzymes speed up the breakdown of food molecules into their respective end products without being used up themselves.
Some examples are: Amylase which breaks down starch into glucose; Pepsin which breaks down proteins into polypeptides; Lipase which converts lipids into fatty acids and glycerol. |
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Describe the importance of the mouth stomach and duodenum in terms of digestion |
Physical digestion takes place in the mouth and food is moistened and lubricated. The conversion of starch to maltose begins here.
Acid contents in the stomach kill bacteria in food. Food is churned into chyme. In babies, curdling of the milk occurs. In adults, protein digestion begins in the stomach, as proteins are converted to polypeptides.
In the duodenum, the enzymes amylase, trypsin and lipase are secreted which break down starch to maltose, which is further broken down into glucose and fructose; polypeptides to amino acids, and lipids into fatty acids and glycerol respectively. Chemical digestion takes place in the duodenum. |
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Describe the route taken by a bolus from the mouth to the anus |
Mouth ➡ oesophagus ➡ stomach ➡ duodenum ➡ ileum ➡ colon ➡ rectum ➡ anus |
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What is the optimum pH of pepsin and trypsin |
Pepsin works best at a pH of 2.5 Trypsin works best at a pH of 8.0 Most enzymes in cells work best at a pH of 7.2 |
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State and briefly describe characteristics of living organism |
Growth, respiration, irritability, movement, nutrition, excretion, reproduction [G.R.I.M.N.E.R] |
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Define the term species |
A species is a group of organisms that share physical characteristics and can breed together to produce fertile offspring |
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What is the binomial system ? |
binomial system is a system of two part Latin names to precisely name and identify different species |
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How do you decide whether something is living are nonliving? |
By making observations and comparing the characteristics of living organisms to the organism |
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State one method of grouping organisms |
One method of grouping organisms is to observe them to find characteristics that they share such as colour, number of legs, wings, shape and size. |
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Define the terms biotic factors and abiotic factors |
Biotic factors refer to all the influences that organisms in the community have on each other.
Abiotic factors are all the non-living features of an ecosystem that influence the organisms in the community. |
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list of examples of biotic and abiotic factors |
Biotic factors - food, disease, predation, competition for food, living space with members of the same species and with other species
Abiotic factors - temperature, water, sunlight, humidity, wind, soil
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Define the term habitat |
The type of place where an organism lives |
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what is an adaptation |
And adaptation is a special characteristic that an organism develops to help it obtain food and water, to move from place to place, to protect itself from predators, to find shelter or to reproduce |
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Give an example of a plant that is adapted to suit its habitat |
A cactus is well adapted to dry conditions.
They have thick spongy stems that can store lots of water, thin spiky leaves to prevent water loss and deep grooves in their stems to allow them to expand and fill up with water whenever it rains. |
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Define the terms population, community and niche |
A population is a group of organisms that belong to the same species living together in a habitat
A community refers to all species of organisms living together in a particular place
A niche refers to a particular position or role that an organism is suited to (including its trophic level and relationship with other organisms) |
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What is a quadrat and what is it used for? |
A quadrant is a frame made of wire or wood that encloses a known area such as 0.25 m sq. or 1m sq.
It makes it easy to sample vegetation and sometimes animal life within a known area |
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Give some examples of sampling methods |
Several sampling methods include: - a quadrat - a line transect - a beating tray - a pooter - sweep nets - pond nets or sieves - pitfall traps |
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What is the formula used to calculate an estimate of the population of in a habitat |
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List the assumptions that must be made when sampling with a quadrat and when using the mark - release - recapture technique |
Not sure * |
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What are the physical features of soil |
water content, water holding capacity, organic and mineral matter, air content, pH, salinity |
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what is essential for the formation of nutrient cycles |
when decomposers are present in a food chain nutrient cycles can be formed |