Lists for biology, ecology, zoology and botany 1, 2, 3

Roles of plant secondary compounds

  1. storage of unwanted products
  2. structural support e.g. cell walls, lignin
  3. plant colour and smell
  4. defence against cold, salinity, UV light
  5. defence against herbivores e.g. alkaloids

Social insects - 3 major traits.

  1. Individuals of the same species co-operate in caring for the young.
  2. There is a reproductive division of labour.
  3. There is an overlap of at least 2 generations in life stages capable of contributing to colony behaviour.

Features of the major evolutionary trends in pollination

trends in pollination mechanisms 3 main which can be observed in flowering plants, plus examples

  1. specialization, e.g. odours, reduction of pollen, fusion of parts, enclosure of nectar, e.g., hammer orchid, yucca
  2. wind, e.g., reduction of floral parts, loss of nectar, separation of sexes, e.g. Festuca rubra
  3. non-specialisation, e.g.- formation of groups of flowers with more or less exposed nectar, e.g., Bellis perennis

Reproductive barriers between species

  1. Ecological isolation. Populations live in different habitats and do not meet.
  2. Temporal isolation. Mating or flowering occur at different seasons or times of the day.
  3. Behavioural isolation. Males and females of the different species are not attracted to each other.
  4. Mechanical isolation. Structural differences in genitalia or flower prevent copulation or pollen transfer.
  5. Gametic isolation. Female and male gametes fail to attract each other, or are inviable.
  6. Hybrid inviability. Hybrid zygotes fail to develop, of fail to reach sexual maturity.
  7. Hybrid sterility. Hybrids fail to produce functional gametes.
  8. Hybrid breakdown. The offspring of hybrids have reduced viability or fertility.

The main parts of a flowering plant and their function.

4 basic types of animal tissue

  1. Epithelial - a sheet of cells that covers an internal or external surface, e.g. lining the lungs, skin
  2. Connective tissue - binds and supports, e.g. bone, cartilage
  3. Muscular tissue - specialises in contraction, e.g. smooth muscle tissue in the intestinal wall, cardiac muscle tissue
  4. Nervous tissue - specialised to receive stimuli and conduct inputs from one region to another, e.g. neurons