Practice questions for Plants

Target Language or Knowledge:

Study the diagram that summarises photosynthesis, then answer the questions below
The two chemicals used in photosynthesis are _water_ and carbon _dioxide,_ the two chemicals produced by _photosynthesis_ are oxygen and _glucose,_ Radiant energy is transformed in photosynthesis from _light_ into chemical energy, _chlorophyll_ so important because it traps sunlight energy.
Lifting Water up a Tree Millions of root hairs provide a large surface area for absorbing water molecules. The cell membrane (surface) of root hair cells is permeable – it allows water molecules to move freely in and out of the cell. The problem is how to get more water molecules moving into the root instead of moving out. Plants use a process called osmosis. This involves the diffusion of water through a membrane from an area of high concentration to an area of low concentration of water.
The next problem is getting water from the roots where it is absorbed up to the leaves where it is used. For some trees this may be over a 100 metres high. The water is transported through bundles of very fine tubes called _xylem_ vessels. The tubes run from the _root_ up to the leaf veins and are filled with _water._ The leaves are losing lots of water owing to _evaporation_ caused by the heating of the Sun. As water molecules evaporate from cells inside the leaf, the concentration of water in those cells drops. So water moves by _osmosis_ from the xylem vessels into the leaf cells. There are strong forces of attraction between water molecules. As the water molecules leave the xylem vessels, the pull up the column of water running down the length of the plant. So water is lifted using the energy of the _Sun_ as it evaporates water from the _leaves._ Plants lose water when they make food, but they use the water loss to pull up more water from the roots! This process is called _transpiration-pull._
Identify where the following processes occur
photosynthesis → leaf, absorption of water → root/ root hairs, reproduction → flower, absorption of minerals → root/ root hairs, transportation of water → stem/ veins, transpiration → leaves, transportation of sugars → veins in stem/ roots
words that are often confused:
_photosynthesis_ transforms sunlight energy to chemical energy stored in food/ _respiration_ releases energy from food b) _evaporation_ occurs when water turns into water vapour/ _transpiration_ is the loss of water from leaves by evaporation c) _diffusion_ is the spreading out of particles from an area of high concentration to areas of low concentration/ _osmosis_ is a special type of diffusion that occurs through the cell membrane d) _evaporation_ occurs when water becomes water vapour/ _condensation_ is when water vapour cools to become liquid again e) _osmotic_ pressure causes water to enter roots/ _transpiration_ pull lifts water up stems and trunks
Use the picture attached and complete the sentences about plant reproduction below
The diagram shows what happens inside a flower once a pollen grain lands on the _stigma_ (top of the female organ). The pollen grain germinates and grows a tube down the style until it reaches a female _gamete_ (egg) inside the _ovary._ The egg is enclosed in the _ovule._ Two male gametes (sperm) travel down the pollen tube and one will enter the egg. Its nucleus will fuse with the egg's nucleus to form a new cell called the _zygote._ This event is called _fertilisation,_ and it is the start of a new plant with different genes from either parent plant. The zygote will grow by cell division and develop into an _embryo_ plant. The ovule, with the embryo and stored food inside it, becomes a _seed._ The _ovary_ develops into a _fruit_ or pod that protects the seeds.
Study the image then answer below.
Plant nutrition involves a chemical process called _photosynthesis._ _Photo_ means light and _synthesis_ means to make. So photosynthesis means making food using light. It only occurs when _light_ is shining on the plant. Like any manufacturing process raw materials and energy are required to make the products. The raw materials for the process of photosynthesis are _water_ and _carbon_ _dioxide_ gas. Water is absorbed from the soil by the _roots,_ and transported up the stem to all parts of the leaf through the network of veins. Carbon dioxide from the air enters the leaf through tiny holes called _stomata_ on the underside of the leaf. _ Chlorophyll_ in the leaves captures _blue_ and red coloured light from the sunlight. _Green_ light is not absorbed but _reflected_ by the leaf, which is why most leaves appear green. The light energy is used to _combine_ water and carbon dioxide molecules to make _glucose_ sugar molecules, which contain much stored _chemical_ energy. In the process of photosynthesis a waste product is made - _oxygen_ gas. This is released to the _atmosphere._ Photosynthesis is the source of the oxygen gas in the atmosphere. The soluble sugar molecules are transported along the _veins_ to other parts of the plant, where they act as a source of energy for growth or they are changed into _insoluble_ starch for _storage._