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13 Cards in this Set
- Front
- Back
outline the transport system in plants, including: - root hair cells |
Water moves by diffusion down concentration gradient by osmosis from the soil into the root cells. Root hairs provide a large surface area. Water moves through center of root and enters the xylem |
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outline the transport system in plants, including: - xylem |
Transport water and mineral ions up to the plant stem to the leaves. Consists of dead cells, whose cross-walls (connection between cell walls) have been broken away, creating a continuous tube. Xylem also gives strength and rigidity to the plant |
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outline the transport system in plants, including: - phloem |
Transport the products of photosynthesis (sugars) throughout the wholeplant. Made of long columns of ‘sieve tube cells’, which have holes in their cellwalls, so that the cytoplasm is mixed and diffusion of sugars occurs. Organic material in the phloem is transported up and down the plant |
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outline the transport system in plants, including stomates |
Stomates are pores in the leaf through which gasses can diffuse. May be present on upper and lower epidermal surfaces, usually on lower. When open, gasses can diffuse freely – rate of photosynthesis increases, when closed – rate of photosynthesis decreases. Guard cells control opening/closing of Stomates |
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outline the transport system in plants, including - lenticels |
These are pores on the woody stems of plants. The gasses needed for respiration are diffused through lenticels. Carbon dioxide also diffuses out. |
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compare open and closed circulatorysystems using one vertebrate and oneinvertebrate as examples Open |
Invertebrates, eg insect - Achieved by simple pumping system consisting of one or more tubular hearts. - Any vessels that assist in the transport of fluid are open at each end. - Fluid is sucked into tubular hearts through small holes and pumped forward to the front of organs and flows slowly backward through spaces surrounding organs. - Only distribute and collect food and wastes as respiratory gasses do not have to be transported- Pressure is low, so circulation is slow - System uses less energy |
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compare open and closed circulatory systems using one vertebrate and one invertebrate as examples Closed |
Vertebrates, larger active animals e.g. human - Consists of a muscular pump (heart) forcing blood through a closed system of tubes (blood vessels) which carry materials rapidly through body - All cells in the body are close to blood vessel - Nutrients, wastes, and gasses exchanged are carried in blood - System use more energy |
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identify mitosis as a process ofnuclear division and explain its role |
- Mitosis is the process by which a multicellular organism grows, repairs, maintains and reproduces itself. - It is a process of division of the nucleus and cytokinesis is division of cytoplasm - Mitosis enables identical copies of each chromosome to be made and passed from mother cell to daughter cell |
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identify the sites of mitosis in plants. |
In mature plants, mitosis occurs in the tips and roots of stems causing an increase in length |
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identify the sites of mitosis in insects. |
When larvae hatch from the egg, they grow as a result of cell enlargement not cell division. In pupal form, the larval cells break down and previously inactive groups of cells start to divide. |
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identify the sites of mitosis in mammals. |
In young mammals, growth is rapid in all areas of the body. At maturity, growth ceases but repair and maintenance of cells continue. In adult mammals, mitosis occurs in the skin and cause hair/fur and nails/claws to grow. New blood cells are made every day in bone marrow. Cells lining digestive system are constantly replaced. |
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explain the need for cytokinesis incell division |
- Cytokinesis describes the division of the cytoplasm. It is necessary to ensure that the chromosome number per cell, remains constant. -Division of the cytoplasm results in two cells, each with a set of chromosomes. -In animal cells cytoplasm constricts at the center, in a process called cleavage. It is necessary to full separate the cells. |
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identify that nuclei, mitochondria, and chloroplasts contain DNA |
Nuclei contain DNA in the form of chromosomes. These contain genetic information that determines heredity. It also has information in producing proteins, which in turn determines ourcharacteristics Mitochondria have a set of DNA of their own. It is a ring of DNA, like in a procaryotic cell. Chloroplasts also have a circular ring of DNA in their own structure |