Coniferophyta: Wood Anatomy, Reproductive Biology, and Climate Adaptation

What is the function of the vascular cambium in conifers?

It divides bifacially to produce secondary phloem on the outer side and secondary xylem on the inner side.

What are the primary conducting cells of the xylem in conifers?

Tracheids.

How do tracheids facilitate water transport?

They use distinct circular bordered pits to allow for the movement of water and minerals between cells.

What is the difference between heartwood and sapwood?

Heartwood is the nonfunctional, lignified center xylem, while sapwood is the outer, functional, non-lignified xylem.

What is cavitation in the context of xylem?

The formation of air bubbles within xylem conduits, often caused by drought stress or broken seals in pit membranes.

What is the primary function of phloem sieve cells?

To transport photosynthates through sieve areas with tiny pores.

Which two lateral meristems are responsible for secondary growth in conifers?

The vascular cambium and the cork cambium.

What components make up the bark of a conifer?

Secondary phloem, living cortical parenchyma cells, and the periderm.

What is the composition of the periderm?

Cork cells, cork cambium, and cork parenchyma.

What is the role of suberin in cork cells?

It is an inert compound that prevents water loss and blocks the entry of pathogens.

What is the function of resin ducts in conifers?

They provide chemical protection against pathogens and insects and help seal wounds.

What are three homologies conifers share with other gymnosperms?

Independence from water for fertilization, gametophyte development within the sporophyte, and the use of seeds for dispersal.

In conifer reproduction, where are megasporangia and microsporangia located?

In separate megastrobili (female cones) and microstrobili (male cones).

What structure forms the female cone in pines?

Aggregated megasporophylls, also known as ovuliferous scales.

What process occurs within the immature microsporangia of a male cone?

Microsporocytes undergo meiosis to produce four haploid microspores.