Answer the following questions. You may use as much space as needed. You must us

Question

Answer the following questions. You may use as much space as needed. You must use one source OTHER than your textbook. Each source you use must have a citation and reference provided. After you have completed this assignment please submit it online as a .doc, .docx or .rtf file.

Part 1: Roots

1.) Explain how to distinguish between the 4 regions/zones of the root structure. Include in your discussion the function of each region.

2.) Japanese gardeners regularly trim away parts of a root system to assist them in dwarfing a plants size. If a plants food is obtained through photosynthesis (in the leaves) why does cutting the roots cause the plant to be smaller in size?

3.) Name one root that is commonly eaten here in the United States

Part 2: Stems

1.) Explain some of the differences in stem structures between monocots and dicots

2.) One of the most commonly used types of stem throughout the world is wood. Explain the different properties that different species of tree possess. How do these characteristics determine how the wood is used.

Part 3: Leaves

1.) Name 3 different types of cells found within a leaf. (Fig 7.6 in your textbook). Explain the function of each type of cell.

2.) Explain what the process of abscission is and how it occurs.

Part 4: Flowers and Seeds

1.) Throughout the plant kingdom, there is a high level of variation in the characteristics of flowers. Flowers are different colors, sizes, shapes, smell different and even bloom at different times. Explain why some of this variation occurs. (In other words, why not look the same as everyone else. Is there an evolutionary advantage to being different?)

2.) Explain why we also see a high level of variation in the structure and appearance of seeds.

Each question needs to use an outside source, and you must have citations and reference for each question.

Explanation / Answer

Answers for Part-I:

Answer-(1):

There are 4 regions or zones of a root, starting from tip and moving upward. These regions are describes as follows:

(i) ROOT CAP- It is a cup shaped region which is made up of parenchymatous cells. Root cap provides protection to the cell and also helps it to penerate into the soil. It has a thin coating of mucin which provides lubrication to the roots, influences proper uptake of ions, attracts those microorganisms from the soil which are beneficial to the plant and protect roots from dying due to drying. They also shows positive geotropism.

(ii) ZONE OF CELL DIVISION- This is a zone that contains apical meristem which are known for their rapid cell division.This zone lies above the root cap. There is an area between apical meristem and root cap which is known as quiescent centre, where most of the cell division occurs and this gives rise to the coloumn of cells that are parallely arranged together. The apical meristemis organized to form 3 distinct layers, namely- protoderm, procambium and ground meri stem.

(iii) ZONE OF CELL ELONGATION- Cells present in this layer lengthen and stretch to form vacuole within the cytoplasm. When this zone expands, it pushes the root cap and the apical tip towards the soil.

(iv) ZONE OF MATURATION- In this zone, differentiation of the elongating cell has been completed. This zone is demarcated by the presence of numerous root hair which are single epidermal cells , extending in the soil whose basic purpose is to absorb water for the plant by increasing the surface area.

Answer-(2):

The process of trimming of roots is also known as Root Pruning. Root trimming cause the dwarfism in plants because this leads to the cutting down of the root caps. It is because of the root capts that a plant can penetrate deeper into the soil, but since root pruning causes cutting of the root caps, roots cannot penetrate deeper into the ground. Therefore, a plant will grown shorter as much as a root can support which causes reduced plant height. Also, it is to be noted that, trimming of roots causes the reduced uptake of essential minerals required for the optimum plant growth.

Answer-(3):

Yam is a root which is commonly eaten in the United States. It belongs to the genus Diasporea.

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.