1.Plant Stem

Question 1

2.41 State the primary functions of stems

Answer 1

State the primary function of stems:

• Hold leaves in optimum position for photosynthesis
• Hold flowers in optimum position for pollination
• Transportation of water, food, nutrients and plant hormones around the plant​
• Many plant stems are green and can also photosynthesis
• Storage of nutrients

Question 2

2.42g State function of Bark

Answer 2

• Very distinctive and can help identify tree’s/shrubs
• May be decorative
• Young bark can be very colourful (e.g willow)
• Exterior epidermis hardens - contains stomata which allow gaseous exchange

Question 3

2.42i Describe the structure and state function of the stem nodes

Answer 3

• The position where leaves and axillary buds are attached to the stem
• Sometimes slightly swollen
• Nodes hold leaves and buds onto the stem
• Distance between two nodes is the internode

Question 4

2.43b Describe how the stem is adapted to perform other functions

Answer 4

• Protection - Thorns help to protect against predators (grazing animals)
• Storage - may swell to hold nutrients during dormancy (perennation)
• Spread - Rhizomes/runners help plants to spread and asexually reproduce
• Support - Climbing plants can form adventitious roots to help the plant access light in higher places

Question 5

What is perennation

Answer 5

• Plants that store nutrients during winter or other seasons when the plant is dormant
• E.g Croms on crocus