Core practical 4

What is pollen in flowering plants?

Pollen is the male gametophyte that produces sperm cells.

What occurs during pollen tube germination?

The pollen tube elongates at the tip from the pollen grain.

What are the components of a female gametophyte in flowering plants?

The female gametophyte consists of egg cell, synergids, polar nuclei, and antipodals.

What environmental condition is necessary for the growth of pollen tubes during experimentation?

A moist environment is necessary to prevent the pollen from drying out.

What effect does sucrose concentration have on pollen tube growth?

Different sucrose concentrations affect the rate and length of pollen tube growth.

How do you measure the growth of pollen tubes in an experiment?

Use a graticule under a microscope to measure and record the length of pollen tubes at set time intervals.

Why is it important to use mature flowers in pollen tube experiments?

Mature flowers are more likely to shed pollen, making germination more likely.

What are the two main forces affecting pollen tube growth after reaching the stigma?

The influx of water from the stigma and the presence of sucrose on the stigma surface.

What is the formula for calculating growth rate in pollen tubes?

Growth rate = total growth distance / total growth time.

What is likely to happen if sucrose concentration is either very low or very high?

Extremely low or high sucrose concentrations will be non-optimal for pollen tube growth.

How do pollen tubes grow by extending their cell membranes?

They grow through changes in their cytoskeleton and adjustments in water potential.

What is a limitation when measuring pollen tube growth across different species?

Different species of pollen have varying rates of germination and growth patterns.