Seeds keep the life cycle of plants going. Plants produce the seed, reproduce more seeds, grow into new plants, and die. The cycle goes on and on. Seeds are all different in shape, color, and size. For protection, seeds have a seed coat on the exterior for protection so that the embryo, a tiny plant, and the endosperm, small leaves that provide the embryo food, don’t dry out or get damaged. All seeds need the right combination of water, oxygen, and the right temperature for the seed to grow. If the seed does not get these three essentials, the seed will stay dormant until it does so.
Activity 1 – Seed Types
Although not all seeds look the same, there are two main types of seeds—the dicotyledon and the monocotyledon. So, how are we able to tell the seed type? Once the seed has sprouted, count how my cotyledon the seed sprouts. The cotyledon is the leaf stored within the seed and the first leaves seed sprouts. A dicotyledon has two cotyledons while the monocotyledon has only one. Another way to tell is looking at the veins of the leaves of the plants. If the veins of the plant are parallel to each other, this indicates that the plant is monocotyledon. An example of this is a palm tree. If the leaves have netlike veins, this means that the type is a dicotyledon. An example of this is the maple tree. Looking at the flowers produced can also tell you the seed type. If the flower parts and has petals in multiples of three, the plan is a monocotyledon. If flower parts and has petals in multiple of four or five, the plant is a dicotyledon.
Using these indicators, find and draw a monocotyledon and dicotyledon seed, leaf, and flower.
Activity 2 – Seed Dispersal
Plants share their offspring as seeds with the world. Unlike animals, which can swim, slide, walk and run to new places, baby seeds are sent off by the wind, carried by the water, or carried by animals to new locations. Some seeds make it to a favorable condition at which to they begin to grow and others do not. Dandelions and milkweeds are seeds carried by the wind. Seeds moved by air have tiny hairs, pods that catch the wind, or are light enough and ‘dust-like’ to be blown hither. Fun wind seeds are the Maple ‘samara wings’ that twirl as they fall! Other seeds float on streams and rivers before washing up to soil to grow. Finally, other seeds have barbs or hooks, or bristles to attach to clothing and fur. Seeds travel for miles to new destinations. Seeds like acorns and nuts are good food sources for animals and are often buried, stashed, and forgotten. In this case, the animals help to ‘plant’ seeds! Some seeds are eaten as food, digested and then eliminated far from the parent plant. Often these seeds are coated in droppings, which add nutrients to aid the seed in sprouting!
Draw three seeds- one carried by air, one by water and one by animals.
Activity 3 – Seed Dormancy
Did you know that seeds ‘sleep’? Seeds hibernate or wait, to germinate or sprout. Some seeds wait for the right temperature, oxygen, and water conditions. Others are programmed to sprout through the use of chemicals within nature or by humans. Seeds ‘sleeping’ is known as dormancy. Some seed seeds sleep due to the impenetrability of their seed coat; others sleep due to internal chemical dormancy. Predictive dormancy and consequential dormancy are two types of hibernation generated on the seed environment. Predictive dormancy is when a seed enters dormancy after a sudden change in the environment, such as the temperature suddenly dropping or when the sunshine time lengthens. Consequential dormancy occurs when a seed begins a sleeping period in response to the environment. Seeds then either die or the change makes the seeds stronger and more productive by keeping the seeds active for a longer period. Look for plants that have gone into dormancy and figure out why. Look for plants that have gone into dormancy and figure out why.
Activity 4 – Seed banks
People all over the world collect, harvest, and save seeds. The majority of saved seeds are for replanting the following season. There is an art to saving seeds. Another reason for saving seeds is to deposit them in a seed bank. Today there are several seed banks around the world dedicated to preserving plant diversity by archiving seeds. To ensure seeds viability after years and years of storage, the temperature and humidity of the storage area need precise regulation. Preserving seeds under controlled conditions can double or even triple the lifespan of seeds. Watch: See inside the Doomsday Seed Bank. Find five of the closest seed banks to you.
Activity 5 – Growing Seeds
Growing seeds is not as hard as you may think it is. You just need a starting pot, seeds, soil, and water! For seeds to grow healthily, you have to make sure that you keep in mind the weather and the season. Seeds successfully grow at different times of the year. The temperature, humidity and hours of sunshine for each season determine the planting and growing period for seeds.
When a seed is growing, the embryo and endosperm work together when conditions are right. The endosperm provides food to the embryo. Once the embryo starts to grow, the embryo breaks through the seed coat. The roots and leaves sprout and enlarge adding buds, leaves and sometimes flowers and fruits.
Try growing your own seeds and take pictures of the different stages.
- Seeds can be dispersed by
- Why does the temperature and humidity need to be regulated in a seed bank?
- What can cause a seed to go into dormancy?
- What are the three most important components needed for a seed to sprout?
- How are you able to tell if a seed is a monocotyledon?