Question

Dry seeds can endure higher temperature than the germinating seeds because
A. Dry seeds have more reserve food
B. Hydration makes the enzyme more sensitive to temperature
C. Dry seeds are hard
D. The seedlings are tender

Answer 1

Dry seeds are produced by those plants that usually produce pods, capsules and seed heads. Seed germination is a process by which the embryo inside the seed will give rise to a plant.

Complete Answer:
A seed is produced as a result of fertilization of the female ovary by the pollen grain. The ovary of the flower sill later develops into the fruit and the ovules inside the ovary will give rise to the seeds. This seed later will germinate and give rise to an entire plant, since it has the presence of an embryo in it. The seed is made up of the following constituents- the embryo formed from the zygote, the endosperm which is normally triploid and the seed coat. The outermost covering of the seed is called the seed coat. The endosperm serves as a temporary food supply to the plant that is present in the form of cotyledons. The seed coat is made up of two layers- outer testa and inner tegma. The outer part of the seed coat is the testa and is the hard part that protects the seed from drying and denies the entry of water and insects inside the tender embryo. To germinate, the seed coat has to be broken down. It is done only during the favorable condition for the plant. Dry seeds have more reserve food as they do not have much water content in them. High amounts of water content will attract pathogens and lead to seed decay. So, in the case of dry seeds, the amount of reserve food material will be low. Hydration makes the enzyme more sensitive to temperature as the amount of water content in the case of dry seeds is less compared to the germinating seeds. The moisture content will soften the tough seed coat and lead to germination. The tough seed coat, in case of dry seeds, can withstand high temperatures and acidic conditions. Hydration will lead to the activation of enzymes and it will break the seed coat and the seed becomes susceptible to temperature. Dry seeds are harder due to the presence of an outer tough seed coat. The seed coat has the capacity to withstand adverse conditions such as high temperatures and changes in the pH. Seedlings are a very small sensitive stage of plant growth. They do not have the capacity to withstand any harsh conditions such as high temperature and high pH. Dry seeds can endure a higher temperature than the germinating seeds as hydration makes the enzyme more sensitive to temperature.
Thus, the right option is B.

Note: The seed coat is mainly composed of proteins that will be broken down by the enzyme proteases. This induces germination in plants. The seed coat can be removed mechanically by rubbing the seed using the fingers or can also be removed using some chemical agents or by application of water.