Instant Notes: Plant Biology

tems (see below), many of the key tissues of the root cannot be observed until they form in the maturation zone (Fig. 1). The va ...

Immature xylem and endodermis can be observed below the area where root hairs form (Fig. 1). Later, above the root hair zone, la ...

Root architecture All plants first form a primary rootand in most plants, including the gymnosperms, primitive dicotyledons and ...

Section C – Vegetative anatomy C3 Herbaceous stems and primary growth Shoot structure Herbaceous stemsare green throughout witho ...

Meristems The shoot meristem produces the cells that will form the major tissues of new stems and leaves. It is organized in lay ...

and is known as the corpus. The central zonecontains actively dividing cells. Leaves and shoots (including new meristems) form i ...

Section C – Vegetative anatomy C4 Woody stems and secondary growth Many species of plant complete their life cycle using only th ...

outside of the cambium to form phloem and the inside to form xylem (Fig. 2). The newly formed secondary phloemandxylemfunction l ...

seasonally varying environments. The center of the trunk of many species is the heartwood, where the vascular system no longer f ...

Section C – Vegetative anatomy C5 Leaves Leaf types The major photosynthetic organ of most plants is the foliage leaf (Fig. 1). ...

around this; others have several parallel veins. In conifers, the leaf is reduced to a needleor scale with a single vascular str ...

Some species such as corn (maize; Zea mays L.) that show C4 photosynthesis(Topic J3), have a leaf structure in which a ring of b ...

...

Section D – Reproductive anatomy D1 The flower Flowersare unique to flowering plants, normally developing on vegetative shoots ( ...

has a more or less swollen top just underneath the flower called the receptacle and on this there are four different organs born ...

epidermal cells but sometimes there is some in the mesophyll too. There are three main types of pigment in petals. The most wide ...

the orchid family there is only one anther and this divides into two pollinia, sticky masses of thousands of pollen grains which ...

tacle and some plants have special nectar-secreting organs, either modified petals or parts of petals. Honeyis made from concent ...

Section D – Reproductive anatomy D2 Pollen and ovules A pollen grain is a single cell derived by meiosis (Topic B5) from pollen ...

disperses. It is this protein that is involved in the recognition interaction of sporophytic self-incompatibility (Topic H3), an ...