Introduction to plant physiology

Question 1

Definition of physiology

Answer 1

Physiology is the study of how systems carry out functions

Cells -> tissues -> organs -> organisms -> populations

Question 2

What are algae?

Answer 2

A disparate group of organisms, spanning prokaryotic and eukaryotic kingdoms / domains

predominately photosynthetic (but not always)

oxygen evolving

simple reproduction

lack cuticles

predominately aquatic …Share similar habitats and habits

About 5000-6000 species recognised from Britain and Ireland

Algae are what algologists (phycologists) study. Algae monitoring is a great way to observe water conditions over time.

Question 3

Plant growth limitations: light

Answer 3

Anthocyanins (red pigment) protects leaves from insects and on the underside of shade dwelling plant leaves they reflect light back to the chloroplasts increasing photosynthesis

Bluebells flower and reproduce in spring before tree leaves develop and shade them

Question 4

Plant growth limitations: water

Answer 4

Tap roots allow plants to bore deep into the ground

If a plant is acccustomed to life immersed in water it utilises gas filled spaces ( created by ethylene initiated programmed cell death) to channel oxygen to the root tissue and prevent rot

Question 5

Plant growth limitations: minerals and nutrients

Answer 5

Legumes can fix nitrogen (via bacterial symbiosis in root nodes)

Insectivorous plants take nutrients from consuming passing insects allowing them to live in nutrient poor soils such as swamplands

Parasitic plants tap into the nutrients collected by host plants some have become fully dependent on hosts and no longer develop chlorophyll or roots e.g. Dodder

Mycorrhizal fungal networks allow plants to exchange carbohydrates for minerals

Question 6

Plant growth limitations: extreme temperatures

Answer 6

Himalayan Rhubarb leaves create a ‘greenhouse effect’ sheltering their new buds and visiting pollinators from the harsh mountain environment

Some plants utilise UV protective pigments

Question 7

Lichen

Answer 7

Lichen is a product of algae/fungi symbiosis

Question 8

The importance of plant science

Answer 8

carbon sinks
soil preservation
agriculture/food production
etc.