Compare and Contrast Plants and Humans as Living Organisms
By Gwennie Tan 10B
Living organisms are defined by the seven characteristics that they have to be capable of in order to be described as being ‘alive’. These are:
Movement – being able of controlled movement
Respiration – being able to gain energy
Sensitivity – being aware of their surroundings
Growth – being able to increase in size and mass
Reproduction – being able to produce offspring
Excretion – being able to get rid of toxic waste products
Nutrition – requiring food for energy
These characteristics can be easily remembered through the acronym MRS GREN. In addition to the seven characteristics ...view middle of the document...
On the other hand, humans have a double circulatory system in where blood passes through the heart twice every cycle. Arteries take blood from the heart so their walls are thick to withstand the pressure. Veins take blood to the heart so they have valves to stop backflow. Capillaries take blood to/from cells so they are only one cell thick for efficient diffusion. Blood within the vessels contain red blood cells to carry out gas exchange, white blood cells which a part of the immune system, plasma which carries dissolved nutrients and platelets which release chemicals to clot wounds.
Regardless of the differences, plants and humans rely on diffusion, osmosis and active transport. Diffusion is the movement of particles down a concentration gradient. It is able to take place with or without a semi-permeable membrane. Meanwhile, osmosis is the movement of water particles across a semi-permeable membrane down a concentration gradient. Both a passive processes, meaning that they do not require energy to occur. Active transport is not a passive process and needs energy in order to transport substances against a concentration gradient. An example would be a plant absorbing minerals from the soil.
Plants also have other ways of transporting such as transpiration stream and capillary action. Water molecules are naturally attracted to each other. When it water evaporates from the surface of the leaf, it draws up other water molecule along with it. Hence, creating a ‘pull’. Capillary action is where
Cells and Organelles
The diagram above displays a so-called ‘typical’ animal cell and plant cell.
Some similarities shared between plant and animal cells include but are not limited to: nucleus, cell membrane, cytoplasm, mitochondrion, ribosomes, golgi apparatus and microtubules. The nucleus controls the activities within the cell by controlling the amount of enzymes produced, a process known as gene expression. The cell membrane holds the cell together and controls what enters or exits it. Cytoplasm is a jelly-like living material where chemical reactions occur in cells. It is semi-permeable, meaning it only allows certain substances to pass through.
Both cells have also mitochondria, known as the ‘powerhouses’ of the cell because of the respiration process that takes place there. This is where glucose and oxygen are broken down to release energy. There are also ribosomes within the endoplasmic reticulum which synthesise proteins that can be used for growth and repair. Golgi body categorises and packages proteins before actively transporting them to parts of the cell where they are needed. Microtubules are present in order to help support both types of cells.
However, plant cells have a rigid cell wall composed of cellulose, which supports the cell when it is in a turgid state. They also have large vacuoles containing cell sap, a weak solution of sugar and...