Question

What is biological species? A morphological species? What is a family?

What is a family in vascular plants?

How can you distinguish between gymnosperm and angiosperm plants? Be specific!

What are the distinguishing characteristics of the following gymnosperm phyla: Ginkgophyta, Coniferophyta, Cycadophyta?

What are the distinguishing characteristics of monocot and eudicot angiosperms?

Answer 1

Biological species: This is a concept to define species on the basis of breeding ability. According to this concept a species is a group of populations which can interbreed and reproductively isolated from other group of populations.

Morphological species: Morphological species is a concept to define species on the basis of morphological similarity. According to this a species is a group of population which are morphologically similar regardles of reproduction inability or genomic differences.

Family: Family is a rank in taxonomy. A family may be named after one of its common members for example, walnuts and hickory trees belong to the family Juglandaceae, commonly known as the walnut family. There is no strict rule for describing a family. Scientist from taxonomy often consider different positions about descriptions of taxa. Therefore the published data often require adjustment over time.

The main difference between angiosperm and gymnosperm is that the angiosperm are flowering plants and they have covered seeds (enclosed within an ovary) while gymnosperms have no flower or fruits and naked seeds on the surface of scales and leaves.

Ginkgophyta: Fan shaped leaves with evenly forking veins.

Coniferophyta: Needle or scale like leaves.

Cycadophyta: Palm like with pinnate leaves.

Monocot: Single cotyledons, Vascular bundles irregularily distributed in stem, lack of true secondary growth, flowers are in the multiple of three and parallel veins occur.

Eudicot: Two cotyledenos, Vascular bundle in ring from in the stem, true secondary growth occurs, Flowers are in the multiple of four or five and reticulated veins occur.