Correct Answer: D. Reduction of agricultural land

Correct Answer: B. seven

Correct Answer: B. has two scars while a seed is has one

Correct Answer: A. They are located near sources of raw materials

Correct Answer: D. Bottom

Correct Answer: B. is not easy to manipulate bills

Correct Answer: B) 3

Explanation

During fertilization, a pollen tube contains three nuclei. These nuclei are involved in the process of double fertilization, which occurs when one sperm nucleus fuses with the egg cell and the other fuses with two polar nuclei to form the endosperm. The endosperm is a nutrient-rich tissue that provides nourishment to the developing embryo in the seed. It is important to understand the process of fertilization in plants, as it plays a crucial role in reproduction and the development of seeds. Pollination occurs when pollen is transferred from the anther of a flower to the stigma of another flower, or to the same flower in self-pollinating plants. The pollen then germinates and grows a tube that penetrates the female reproductive structure of the flower, the ovule. Once the pollen tube reaches the ovule, it releases the three nuclei it contains. One of these nuclei fuses with the egg cell to form the zygote, which develops into the embryo. The other two nuclei fuse with the polar nuclei to form the endosperm. This process of double fertilization ensures that the developing embryo has enough nutrients to grow and develop into a mature seed. In conclusion, a pollen tube during fertilization contains three nuclei, which are involved in the process of double fertilization and the formation of the endosperm. Understanding the process of fertilization in plants is important for understanding their reproduction and the development of seeds.

Explanation

(a) Differences between the Tropical Grassland and Temperate Grassland

Tropical grasslands are located between 5° and 20°North and South of the Equator while Temperate grasslands are located between 45° and 600 in the Northern hemisphere and between 25° and 40° in the Southern hemisphere. Tropical grasslands are found in West Africa, East and Central Africa, North of Capricorn and South America while Temperate grasslands are found in the heart of Asia, North America, South Africa, Argentina and in the Darling Plains of Australia. In West Africa, Tropical grasslands are known as savanna. In South America they are known as Llanos, Campos in Brazil whereas the temperate grasslands are known as Steppe in Asia, Prairie in North America, Veld South Africa, Pampas in Argentina and Down in Australia. Tropical grassland is consists mainly of grasses and the height vary from about 2 - 3 metres while temperate grassland is composed of very short grasses. Grasses in the tropical grassland are more compact while that of the temperate grasslands are generally sparse and often in discontinuous clumps. The trees of the Tropical grassland are many while in temperate grassland they are few and in some area non-existence. Trees in tropical grassland are about 10-20m or more, they are tall and scattered while in temperate grassland, they are shorter. The trees of the tropical grassland have long tap roots while trees in temperate grassland have shorter roots.The grasses of the temperate grassland are more nutritious to animals than those of the tropical grassland. in tropical grassland, the popular trees are acacia,baobab, shea butter while in the temperate grasslands trees are poplar, willows and alders.

(b)(i) Description of the climate associated with:

The Tropical Grassland

• It has two distinct seasons of wet and dry.
• Dry seasons are long while the wet seasons are short.
• Temperature is uniformly high ranging between 27°C and 32°C (80°F and 90°F).
• Annual temperature range is about 11°C.
• Rainfall is mainly convectional and it falls in wet season.
• Relative humidity is high during the rainy season (60%) with single maximum rainfall.

The dry season is characterized by

• low relative humidity (20%).
• Clouds are thick and low during the rainy season.
• Insolation is considerably reduced during the rainy season by clouds.
• It is high during the dry season.
• There is abundant sunshine throughout the year.
• Winds are rain-bearing in wet season, but hot, dry and dusty in the dry season.

(ii) The Temperate Grassland

• The temperate grassland has four seasons namely, summer, autumn, winter and spring.
• The climate is continental.
• Temperature is high in summer, usually more than 25°C (77°F) and cold in winter to the freezing point.
• It has a high range of temperature.
• Rainfall is usually very high and it is between 400mm and 600mm.
• Rainfall is convectional.
• Humidity is very high during the summer, clouds are generally light for most of the year.
• They become heavy before the rains.
• The areas are influenced by South Westerlies.

Correct Answer: D. hurt their husbands

Correct Answer: (b) Demand exceeds supply