Plants & Conservation (Edexcel International A Level Biology)

Seed banks are used to store seeds from a wide variety of plants. Some plants are a sustainable source of bioplastics.

The Germplasm Bank of Wild Species is the largest seed bank for wild species of plants in Asia.

Seeds from 8 500 species have been collected and stored.

Seeds were dried before being stored at temperatures below 0 °C.

The effect of length of time in storage on seed germination is shown in the graph.

Describe the effect of length of time in storage on the germination of these seeds.

(2)

(ii)

Two of the methods used in seed banks are:

• store seeds from many different plants of the same species, instead of many seeds from just one plant

• regularly germinate samples of the stored seeds, allowing them to grow into adult plants.

Explain the advantages of these methods.

(4)

The photograph shows bioplastic straws and cutlery. Bioplastic can be produced from the seeds of avocados.

F. Kesselring, FKuR Willich, CC BY-SA 3.0 DE <https://creativecommons.org/licenses/by-sa/3.0/de/deed.en>, via Wikimedia

In 2018, a company in Mexico produced 130 000 kg of bioplastic cutlery and straws per month.

40 % of the products were straws.

Calculate the mass of cutlery produced per year by this company.

Give your answer to two significant figures.

(2)

(ii)

The use of these plant-based products is more sustainable than the use of cutlery and straws made from oil-based plastic.

Explain what is meant by the term sustainable, with reference to the cutlery produced from the seeds of avocados.

(2)