Biology 12Th: Ch 21 Short Qs

Looking for some quick solutions to the biology 12th class chapter 21 short questions? You’ve come to the right place! In this article, we will dive straight into the answers you need, without any unnecessary prelude. Whether you’re struggling with understanding concepts or need help with specific questions, we’ve got you covered. Throughout this conversation, we will seamlessly incorporate valuable information to help you grasp the key concepts of biology 12th class chapter 21 short questions. So, let’s get started!

Biology 12th: Ch 21 Short Qs

Biology 12th Class Chapter 21 Short Questions: A Comprehensive Guide


Welcome to our comprehensive guide on Biology 12th Class Chapter 21 short questions. In this article, we will explore the important concepts and questions from this chapter, providing you with a thorough understanding of the topic. Chapter 21 focuses on various aspects of genetics, including inheritance, gene expression, and genetic disorders. By going through the short questions and their answers, you will be able to enhance your knowledge and perform well in your exams. Let’s dive in!

Overview of Chapter 21: Genetics

Before we dive into the short questions, let’s have a brief overview of Chapter 21. This chapter is a crucial part of the Biology syllabus for the 12th class. It covers the fundamental principles of genetics and how traits are transmitted from one generation to another. Some key topics covered in this chapter are:

1. Mendel’s Laws of Inheritance
2. Human Genetic Disorders
3. Chromosomal Abnormalities
4. Molecular Basis of Inheritance
5. DNA Replication and Protein Synthesis

Understanding these concepts is essential for developing a strong foundation in genetics. Now, let’s move on to the short questions from this chapter.

Short Questions:

1. Explain Mendel’s Laws of Inheritance.

Mendel’s Laws of Inheritance form the basis of modern genetics. They are as follows:

  • Law of Segregation: This law states that each organism possesses two alleles for a trait, and these alleles segregate or separate during gamete formation, with only one allele passing to each offspring.
  • Law of Independent Assortment: According to this law, the alleles of different genes segregate independently during gamete formation. This means that the inheritance of one trait does not influence the inheritance of another trait.

These laws help explain how traits are inherited and why certain variations appear in offspring.

2. What are some common human genetic disorders?

Human genetic disorders are conditions caused by abnormalities in the genes or chromosomes. Some common genetic disorders include:

  1. Down Syndrome: A condition where an individual has an extra copy of chromosome 21, resulting in physical and cognitive impairments.
  2. Cystic Fibrosis: A genetic disorder that affects the respiratory and digestive systems, leading to thick mucus production and organ damage.
  3. Hemophilia: A disorder that affects the blood’s ability to clot properly, leading to excessive bleeding.
  4. Sickle Cell Anemia: A genetic disorder characterized by abnormally shaped red blood cells, leading to pain, organ damage, and anemia.
  5. Huntington’s Disease: A neurological disorder that causes the progressive deterioration of brain cells, resulting in impaired movement, cognition, and behavior.

These disorders highlight the importance of understanding genetics and the implications they have on human health.

3. What are chromosomal abnormalities?

Chromosomal abnormalities occur when there are changes in the number or structure of chromosomes. Some common types of chromosomal abnormalities include:

  • Trisomy: A condition where there is an extra copy of a chromosome, such as Down Syndrome (trisomy 21).
  • Monosomy: A condition where there is a missing copy of a chromosome, such as Turner Syndrome (monosomy X).
  • Translocation: A condition where a piece of one chromosome breaks off and attaches to another chromosome.
  • Deletion: A condition where a portion of a chromosome is missing.
  • Duplication: A condition where a segment of a chromosome is duplicated.

Chromosomal abnormalities can lead to various health conditions and developmental issues.

4. Explain the process of DNA replication.

DNA replication is the process by which a DNA molecule is copied to produce two identical DNA molecules. The process involves several steps:

  1. Initiation: DNA replication begins at specific sites called origins of replication. Enzymes called helicases unwind and separate the two DNA strands.
  2. Elongation: DNA polymerase enzyme adds new nucleotides to the growing DNA strands, following the base pairing rule (A-T, G-C).
  3. Termination: The replication process continues until it reaches specific termination sites on the DNA molecule.

DNA replication ensures that each new cell receives an exact copy of the genetic information.

5. How does gene expression occur?

Gene expression is the process by which information from a gene is used to synthesize a functional gene product, such as a protein. It involves several steps:

  1. Transcription: The first step of gene expression, where the DNA sequence of a gene is transcribed into mRNA by RNA polymerase.
  2. RNA Processing: The pre-mRNA undergoes several modifications, including the removal of introns and addition of a poly-A tail and a cap.
  3. Translation: The mRNA is transported to the cytoplasm, where ribosomes decode the mRNA sequence and synthesize a specific protein.

Gene expression plays a crucial role in determining an organism’s traits and functions.

In conclusion, Biology 12th Class Chapter 21 covers important concepts related to genetics. By thoroughly understanding the short questions presented in this guide, you will be well-prepared for your exams. Remember to go through each topic’s details, such as Mendel’s Laws of Inheritance, human genetic disorders, chromosomal abnormalities, DNA replication, and gene expression. Practicing these short questions will help solidify your understanding and improve your performance in biology. Happy studying!

2nd year biology CH 21 cell cycle part 1 SQ and LQ||

Frequently Asked Questions

What is the structure and function of ribosomes?

Ribosomes are small, spherical organelles found in both prokaryotic and eukaryotic cells. They are responsible for protein synthesis, converting the genetic information stored in mRNA into functional proteins. Ribosomes consist of a large subunit and a small subunit, each composed of ribosomal RNA (rRNA) and proteins. They can be found free in the cytoplasm or bound to the endoplasmic reticulum.

What are the differences between smooth and rough endoplasmic reticulum?

The endoplasmic reticulum (ER) is a network of membrane-bound tubules and sacs found throughout the cytoplasm. The smooth ER lacks ribosomes on its surface and is involved in lipid metabolism, detoxification, and calcium storage. On the other hand, the rough ER is studded with ribosomes and is involved in protein synthesis, folding, and transportation.

What roles do lysosomes play in cellular function?

Lysosomes are membrane-bound vesicles containing digestive enzymes. They function as the “recycling centers” of the cell, breaking down waste materials, cellular debris, and foreign substances. Lysosomes also play a critical role in autophagy, the process of breaking down and recycling damaged or unnecessary cellular components to maintain cell homeostasis.

How do mitochondria generate energy in the form of ATP?

Mitochondria are often referred to as the “powerhouses” of the cell because they are responsible for generating energy in the form of ATP (adenosine triphosphate). This process, called cellular respiration, occurs in the inner mitochondrial membrane. Mitochondria utilize the electron transport chain to extract energy from nutrients, such as glucose, and convert it into ATP through oxidative phosphorylation.

What are the differences between plant and animal cells?

Although plant and animal cells share many similarities, there are several key differences. Plant cells have a rigid cell wall composed of cellulose, while animal cells lack a cell wall. Plant cells also contain chloroplasts for photosynthesis, large central vacuoles for storage, and plasmodesmata for cell communication. Animal cells, on the other hand, have centrioles for cell division and a variety of specialized structures, such as cilia and flagella.

Final Thoughts

The short questions in the biology 12th class chapter 21 provide a comprehensive review of the topics covered in the chapter. They allow students to test their understanding and knowledge of various concepts related to biology. By practicing these short questions, students can reinforce their learning, improve their problem-solving skills, and prepare effectively for their exams. Answering these questions will help students gain a deeper understanding of the biological principles discussed in the chapter, such as cell division, genetics, and evolution. So, if you’re looking to assess your understanding and grasp of biology 12th class chapter 21, these short questions are a valuable resource.

Related Posts
What Is the Date of 9th Class Result 2023 Lahore Board?
what is the date of 9th class result 2023 Lahore board?

For all the 9th class students eagerly waiting for their results, To know about What Is the Date of 9th Read more

What Is the Date of 9th Class Result 2023 Gujranwala Board?
What Is the Date of 9th Class Result 2023 Gujranwala Board?

The long wait is finally coming to an end for the students who ask What Is the Date of 9th Read more

What Is the Date of 9th Class Result 2023 Rawalpindi Board?
What Is the Date of 9th Class Result 2023 Rawalpindi Board?

The wait is almost over for the Student who is asking about What Is the Date of 9th Class Result Read more

What Is the Date of 9th Class Result 2023 Multan Board?
What Is the Date of 9th Class Result 2023 Multan Board?

For all the 9th class students anxiously waiting for What Is the Date of 9th Class Result 2023 Multan Board? Read more