6452 Solved Assignment spring 2023

Course: Biology-II (6452)                  Semester: Spring, 2023

Level: B.Ed. (2.5/4-Year)

Assignment no 1

Question 1: The Characteristics, Economic Importance, and Distribution of Family Solanaceae

Question: Write in detail diagnostic characteristics, economic importance, and distribution pattern of family Solanaceae.

Answer:

Diagnostic Characteristics: The family Solanaceae, also known as the nightshade family, comprises a diverse group of flowering plants. Key diagnostic features include:

• Flower Structure: Solanaceae flowers are typically bisexual and radially symmetric, with five fused petals and sepals. The corolla often forms a distinct tube.
• Stamens: Solanaceae flowers have five stamens with versatile anthers, capable of moving to contact pollinators.
• Fruit Type: The fruit can be a berry, capsule, or drupe.
• Leaves: The leaves vary widely in shape, often alternating along the stem.
• Alkaloids: Many members of Solanaceae contain alkaloids, chemical compounds that contribute to their toxicity.

Economic Importance: The Solanaceae family includes several economically significant plants:

• Potato (Solanum tuberosum): One of the world’s major food crops, potatoes provide a vital source of carbohydrates and are consumed globally.
• Tomato (Solanum lycopersicum): Widely cultivated for its nutritious fruits, tomatoes are used in various culinary dishes.
• Tobacco (Nicotiana tabacum): The source of nicotine, tobacco has cultural, economic, and medical significance.
• Pepper (Capsicum spp.): Various pepper species are cultivated for their pungent fruits, which are used as spices.
• Eggplant (Solanum melongena): Valued for its edible fruits, eggplants are consumed in numerous cuisines.

Distribution Pattern: The Solanaceae family is distributed globally, with members found in diverse habitats. Many species thrive in temperate and tropical regions, adapting to various soil types and climates. Some, like tomatoes and peppers, are cultivated in a wide range of regions due to their economic value. Others, such as certain nightshades and belladonna, grow in specific environments like woodlands, open fields, and disturbed areas.

Question 2: Differentiating Temporary and Permanent Tissues

Question: Differentiate temporary and permanent tissues on the basis of structure and functions.

Answer:

Temporary Tissues: Temporary tissues, also known as meristematic tissues, are involved in growth and cell division. They are found in regions where active growth occurs, such as the tips of stems and roots. Key characteristics include:

• Structure: Cells are small, thin-walled, and closely packed. Nuclei are large and prominent.
• Function: Temporary tissues give rise to new cells through mitotic divisions, contributing to primary growth in plants. They differentiate into various specialized cells.

Permanent Tissues: Permanent tissues, as the name suggests, are mature tissues that have completed their growth and differentiation. They can be further classified into simple and complex permanent tissues:

• Simple Permanent Tissues: These include parenchyma, collenchyma, and sclerenchyma tissues, each with distinct functions such as storage, support, and protection.
• Complex Permanent Tissues: These tissues, such as xylem and phloem, are responsible for transporting water, nutrients, and sugars throughout the plant.

Question 3: Drawing and Labeling the Structure of an Ovule

Question: Draw the structure of an ovule and label its different parts.

Answer: (Ovule structure diagram goes here) Labeling:

• Integuments: Protective layers surrounding the ovule.
• Micropyle: Small opening in the integuments, through which the pollen tube enters during fertilization.
• Nucellus: The central mass of cells within the ovule.
• Megasporangium: The nucellus contains the megasporangium, where megaspores are produced.
• Megaspore: One of the daughter cells resulting from meiotic division within the megasporangium.

Question 4: Describing Different Levels of Protein Structure

Question: Describe different levels of protein structure.

Answer:

Proteins exhibit several levels of structural organization, each contributing to their functional properties:

1. Primary Structure: This is the linear sequence of amino acids in a protein. It is determined by the genetic code encoded in DNA. A slight change in the sequence can lead to significant alterations in protein function.
2. Secondary Structure: Secondary structure refers to local folding patterns within a protein chain. Common secondary structures include alpha helices and beta sheets. These structures are stabilized by hydrogen bonds between amino acids.
3. Tertiary Structure: Tertiary structure is the overall 3D arrangement of a protein’s secondary structures. It results from interactions between amino acid side chains, including hydrogen bonds, ionic bonds, hydrophobic interactions, and disulfide bridges.
4. Quaternary Structure: Quaternary structure is relevant only for proteins composed of multiple subunits. It describes the arrangement of these subunits in the functional protein complex. Interactions between subunits involve the same types of bonds found in tertiary structure.

These hierarchical levels of protein structure collectively determine a protein’s shape, stability, and function.

Question 5: Notes on Diagnostic Features of Family Apiaceae and Different Levels of Protein Structure

Question: Write notes on the following: Diagnostic features of Family Apiaceae, Different levels of protein structure.

Answer:

Diagnostic Features of Family Apiaceae: The family Apiaceae, also known as the parsley family or carrot family, is characterized by several distinctive traits:

• Inflorescence: Umbels, characteristic umbrella-like clusters of flowers, are a defining feature.
• Leaf Arrangement: Leaves are often compound and arranged alternately along the stem.
• Stems: Hollow stems are common, containing channels that transport essential oils.
• Aromatic Compounds: Many members of Apiaceae produce aromatic compounds, contributing to their distinctive flavors and scents.
• Fruits: Fruits are usually schizocarpic, breaking into mericarps (segments) at maturity.

Different Levels of Protein Structure: Proteins exhibit a hierarchy of structural levels, contributing to their intricate functions:

• Primary Structure: The linear sequence of amino acids, encoded by the genetic code.
• Secondary Structure: Local folding patterns, such as alpha helices and beta sheets.
• Tertiary Structure: The overall 3D arrangement of secondary structures.
• Quaternary Structure: Relevant for multi-subunit proteins, describing their arrangement in functional complexes.