2021 - JAMB Biology Past Questions and Answers - page 1

Vascular tissue is comprised of the xylem and the phloem, the main transport systems of plants.

xylem, plant vascular tissue that conveys water and dissolved minerals from the roots to the rest of the plant and also provides physical support.

Wind-pollinated flowers:

• No bright colors, special odors, or nectar.
• Small.
• Most have no petals.
• Stamens and stigmas exposed to air currents.
• Large amount of pollen.
• Pollen smooth, light, easily airborne.
• Stigma feathery to catch pollen from wind.

•  cold-blooded ness;
• The teeth of reptiles are also less specialized in function than are mammalian teeth.
• a dry skin with scales but not feathers (a characteristic of birds) or hair (a characteristic of mammals);

NB: Birds do not have teeth, although they may have ridges on their bills that help them grip food.

       Birds swallow their food whole, and their gizzard (a muscular part of their stomach) grinds up the food so they can digest it.

The functional group in a food chain include:

Primary producer → Primary consumer → Secondary consumer

Grass, grasshopper, toad, snake, hawk

- The most familiar invertebrates include the Protozoa, Porifera, Coelenterata, Platyhelminthes, Nematoda, Annelida, Echinodermata, Mollusca and Arthropoda.

- Invertebrates are animals that neither possess nor develop a vertebral column, derived from the notochord.

Exosmosis is the movement of water outside the cells when a cell is placed in a hypertonic solution.

The cell becomes flaccid by the movement of water outside.

Air Pollutants

• Carbon Monoxide.
• Lead.
• Nitrogen Oxides.
• Ozone.
• Particulate Matter.
• Sulfur Dioxide.
• Other Air Pollutants.

The primary pollutants of concern in land and soil are heavy metals, such as lead, mercury and others, pesticides and other persistent organic pollutants, and pharmaceuticals, such as antibiotics used for livestock management.

Nitrogen (N), nonmetallic element of Group 15 [Va] of the periodic table.

It is a colourless, odourless, tasteless gas that is the most plentiful element in Earth's atmosphere and is a constituent of all living matter.

Percentage of water content (retained) = \(\frac{Water absorbed}{Weight of soil} * 100\) 

→ \(\frac{50 - 35}{50} * 100\)

= 30%

When the queen dies, production of the blocking pheromone stops, and secondary reproductives may be produced.

In the Reticulitermes species, the queen and king may be replaced by numerous secondary reproductives, and the colony may become very large with the added productivity of many queens.