Genetics and evolution MCQ Quiz - Objective Question with Answer for Genetics and evolution - Download Free PDF

The correct answer is by both paternal DNA and maternal DNA.

Key Points

• Traits are inherited from both paternal (father's) DNA and maternal (mother's) DNA.
• Each parent contributes 50% of the DNA, which combines to form the unique genetic makeup of an individual.
• The combination of maternal and paternal DNA influences the traits and characteristics of the offspring.
• This process of inheritance follows the principles of Mendelian genetics, which explains how traits are passed from parents to offspring.

Additional Information

• DNA (Deoxyribonucleic Acid)
  • DNA is a molecule that contains the genetic instructions used in the growth, development, functioning, and reproduction of all known living organisms and many viruses.
  • It is composed of two strands that coil around each other to form a double helix.
  • Each strand is made up of a sequence of four types of nucleotides: adenine (A), thymine (T), cytosine (C), and guanine (G).
• Genes
  • Genes are segments of DNA that carry hereditary information.
  • They are responsible for the inherited traits and characteristics of an organism.
  • Each gene occupies a specific location on a chromosome.
• Chromosomes
  • Chromosomes are long DNA molecules with part or all of the genetic material of an organism.
  • Humans have 23 pairs of chromosomes, for a total of 46.
  • One set of 23 chromosomes is inherited from the mother, and the other set is inherited from the father.
• Mendelian Genetics
  • Gregor Mendel, the father of genetics, discovered the basic principles of heredity through experiments with pea plants.
  • Mendelian genetics explains how traits are inherited through the interaction of alleles, which are different forms of a gene.
  • Traits can be dominant or recessive, and the combination of alleles from both parents determines the traits of the offspring.

The correct answer is One pair.

Key Points

• Humans have a total of 23 pairs of chromosomes, out of which one pair is the sex chromosomes.
• The sex chromosomes determine the biological sex of an individual; females have two X chromosomes (XX), while males have one X and one Y chromosome (XY).
• The remaining 22 pairs of chromosomes are called autosomes and are identical in both males and females.
• The presence of the Y chromosome triggers male development, while its absence (having two X chromosomes) results in female development.

Additional Information

• Autosomes:
  • These are the 22 pairs of chromosomes that are not involved in determining the sex of an individual.
  • Autosomes contain genes that regulate various body functions and traits.
• Karyotype:
  • A karyotype is the number and appearance of chromosomes in the nucleus of a eukaryotic cell.
  • It is used in clinical genetics to diagnose chromosomal abnormalities.
• Genetic Disorders:
  • Disorders like Turner syndrome and Klinefelter syndrome are caused by abnormalities in the sex chromosomes.
  • Turner syndrome occurs in females with one X chromosome (45,X), while Klinefelter syndrome occurs in males with an extra X chromosome (47,XXY).
• Chromosome Function:
  • Chromosomes are structures within cells that contain DNA and many genes.
  • They play a crucial role in cell division, replication, and the transmission of genetic information.

The correct answer is To track the inheritance of specific traits across generations within a family.

Key Points

• Pedigree analysis is used to determine the inheritance pattern of traits in humans, such as autosomal dominant, autosomal recessive, or X-linked traits.
• This method helps in predicting the probability of an individual inheriting a specific trait or disorder by analyzing family history.
• It is crucial for genetic counseling, enabling families to understand the risks of genetic disorders.
• Pedigree charts visually represent the relationships and traits of family members across generations, simplifying the analysis.

Additional Information

• Autosomal Dominant Trait
  • Only one copy of the altered gene is needed for the trait to be expressed.
  • Affected individuals have a 50% chance of passing the trait to their offspring.
• Autosomal Recessive Trait
  • Two copies of the altered gene are required for the trait to be expressed.
  • Carriers have one copy of the altered gene but do not show symptoms of the trait.
• X-Linked Traits
  • Traits associated with genes found on the X chromosome.
  • Males are more frequently affected due to having only one X chromosome.
• Genetic Counseling
  • A process to evaluate and understand a family's risk of an inherited medical condition.
  • Genetic counselors provide information and support to families who may be at risk for a variety of inherited conditions.

The correct answer is by both paternal DNA and maternal DNA.

Key Points

• Traits are inherited from both paternal (father's) DNA and maternal (mother's) DNA.
• Each parent contributes 50% of the DNA, which combines to form the unique genetic makeup of an individual.
• The combination of maternal and paternal DNA influences the traits and characteristics of the offspring.
• This process of inheritance follows the principles of Mendelian genetics, which explains how traits are passed from parents to offspring.

Additional Information

• DNA (Deoxyribonucleic Acid)
  • DNA is a molecule that contains the genetic instructions used in the growth, development, functioning, and reproduction of all known living organisms and many viruses.
  • It is composed of two strands that coil around each other to form a double helix.
  • Each strand is made up of a sequence of four types of nucleotides: adenine (A), thymine (T), cytosine (C), and guanine (G).
• Genes
  • Genes are segments of DNA that carry hereditary information.
  • They are responsible for the inherited traits and characteristics of an organism.
  • Each gene occupies a specific location on a chromosome.
• Chromosomes
  • Chromosomes are long DNA molecules with part or all of the genetic material of an organism.
  • Humans have 23 pairs of chromosomes, for a total of 46.
  • One set of 23 chromosomes is inherited from the mother, and the other set is inherited from the father.
• Mendelian Genetics
  • Gregor Mendel, the father of genetics, discovered the basic principles of heredity through experiments with pea plants.
  • Mendelian genetics explains how traits are inherited through the interaction of alleles, which are different forms of a gene.
  • Traits can be dominant or recessive, and the combination of alleles from both parents determines the traits of the offspring.

The correct answer is Heterochromatin.

Key Points

• Heterochromatin is a tightly packed form of DNA, which comes in multiple varieties and is generally transcriptionally inactive.
• It stains more darkly with nuclear stains compared to euchromatin due to its denser structure.
• Heterochromatin is often found at the periphery of the nucleus in eukaryotic cells.
• It plays a crucial role in maintaining the structure of the chromosome and regulating gene expression.
• There are two main types of heterochromatin: constitutive and facultative.

Additional Information

• Euchromatin
  • Euchromatin is a lightly packed form of DNA that is often (but not always) under active transcription.
  • It is found in the inner body of the nucleus and stains lightly.
  • Euchromatin represents the major genes and is involved in transcription.
  • It appears less compact under a microscope compared to heterochromatin.
• Constitutive Heterochromatin
  • This type of heterochromatin is permanently compacted and is typically found in regions like centromeres and telomeres.
  • It contains repetitive DNA sequences and is involved in structural functions such as chromosome stability.
• Facultative Heterochromatin
  • This type of heterochromatin can switch between being compacted and decompacted depending on the cell's needs.
  • An example is the inactivation of one of the X chromosomes in female mammals (Barr body).
• Chromosomal Proteins
  • These proteins, such as histones, play a role in the structural organization of chromatin.
  • They help in the packaging of DNA into the compact form that fits inside the cell nucleus.

The correct answer is ,

Key Points

• Both mitochondria and chloroplasts possess their own genetic material thus, they are called semi-autonomous organelles.
• The mitochondrial DNA and plastid DNA possess genes that produce the proteins necessary for the functioning of mitochondria and chloroplasts respectively.

Important Points

• Mitochondria (sing.: mitochondrion), unless specifically stained, are not easily visible under the microscope.
• The number of mitochondria per cell is variable depending on the physiological activity of the cells.
• In terms of shape and size also, a considerable degree of variability is observed.
• Typically it is sausage-shaped or cylindrical having a diameter of 0.2-1.0µm (average 0.5µm) and length 1.0-4.1µm.
• Each mitochondrion is a double membrane-bound structure with the outer membrane and the inner membrane dividing its lumen distinctly into two aqueous compartments, i.e. the outer compartment and the inner compartment.

The correct answer is Paleontology.

• Palaeontology is the scientific study of the life of the geologic past.
• It includes the study of plant and animal fossils, including those of microscopic size, preserved in rocks.
• It is concerned with all aspects of the biology of ancient life forms: their shape and structure, evolutionary patterns, taxonomic relationships with each other and with modern living species, geographic distribution, and interrelationships with the environment. 

Additional Information

Osteology

• Osteology is the science that deals with human skeleton recovery and interpretation.

Histology 

• Histology is the science of the microscopic structure of cells, tissues, and organs.
• It also helps us understand the relationship between structure and function.

Mycology

•  Mycology is the study of fungi, their relationships with each other and other organisms.

Concept-

• DNA stands for Deoxyribonucleic acid.
• DNA as an acidic substance present in the nucleus was first identified by Friedrich Meischer in 1869.
• He named it ‘Nuclein’.
• DNA acts as the genetic material in most organisms.
• A DNA molecule consisting of all the genetic material of an organism is known as a chromosome.
• These are thread-like (helical) structures of protein and nucleic acids which​ carry all the genetic information in the form of genes.

Explanation-

• ​Deoxyribonucleic acid (DNA) is a nucleic acid and is therefore made up of nucleotide.
• Each nucleotide consists of a phosphate group, a nitrogenous base (A, T, G, C), and ribose sugar (deoxyribose in case of DNA).
• A nucleoside contains only pentose sugar and a nitrogenous base.
• Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) are the two types of nucleic acids found in living systems.
• DNA is a long polymer of deoxyribonucleotides.
• The length of DNA is usually defined as the number of nucleotides (or a pair of nucleotides referred to as base pairs) present in it.

Thereby DNA is composed only of nucleic acid.

Additional Information

Lipids: 

• ​These organic compounds are nonpolar molecules, which are soluble only in nonpolar solvents and insoluble in water because water is a polar molecule.
• In the human body, these molecules can be synthesized in the liver and are found in oil, butter, whole milk, cheese, fried foods, and also in some red meats.

Proteins:

• Proteins are composed of amino acids, arranged into different groups.
• These fundamental amino acid sequences are specific and their arrangements are controlled by the DNA. 
• These are the fundamental building blocks of our bodies.
• They are large and complex macromolecules or bio-molecules which perform a major role in the functioning and regulating of our body cells, tissues, and other organs in the human body.​

The correct answer is 46.

Key Points

• In humans, each cell normally contains 23 pairs of chromosomes, for a total of 46.
• Twenty-two of these pairs, called autosomes, look the same in both males and females.
• The 23rd pair, the sex chromosomes, differ between males and females.
• Females have two copies of the X chromosome, while males have one X and one Y chromosome.

Additional Information

• Chromosomes are thread-like structures located inside the nucleus of animal and plant cells.
• Each chromosome is made of protein and a single molecule of deoxyribonucleic acid (DNA).
• Passed from parents to offspring, DNA contains the specific instructions that make each type of living creature unique. 

The correct answer is option 1 i.e., Transcription.

Key Points

• Transcription is the process of copying the genetic information on the RNA from one of the DNA.
• The process involves copying a gene's DNA sequence to make an RNA molecule.
• DNA safely stores genetic material in the nuclei of cells as a template.
• Transcription is carried out by an enzyme called RNA polymerase.
• Transcription ends in a process called termination.

Additional Information

• Transformation - is a process by which DNA molecules can be transferred between microbial cells.
• Translation - is the process by which the amino acid chains (polypeptides) are formed from mRNA during protein synthesis.

The correct answer is Uracil and Cytosine.

• Pyrimidine is one of two classes of heterocyclic nitrogenous bases found in the nucleic acids DNA and RNA.
• In RNA the pyrimidines are uracil and cytosine.
• In DNA the pyrimidines are cytosine and thymine.

  Additional Information

• Uracil is one of the four naturally occurring pyrimidine nucleobases.
• They are represented by the letters A, G, C, U and T.
• The others are adenine (A), cytosine (C), and guanine (G) and thymine (T).
• In RNA, uracil binds to adenine via two hydrogen bonds.

The correct answer is option 1, i.e. Darwin's theory of evolution.

Key Points

Darwin's theory of evolution tells us how life evolved from simple to more complex form.

• Evolution is a process of change happening over generations.
• Darwin published his theory of evolution with evidence in his book 'On the Origin of Species' in 1859.
• The book introduced the scientific theory of evolution over the course of generations through the process of Natural Selection.

The correct answer is Cytoplasm.

Key Points

Cytoplasm

• The cytoplasm is one of the basic components of the cell where cell organelles are embedded. 
• It is a semi-liquid jelly-like element composed of salt and water and is present within the membrane of the cells and embeds all of the parts of the cells and organelles.
• Other cell organelles such as mitochondria, ribosomes, vacuoles, endoplasmic reticulum, etc., are all suspended in it.
• The cytoplasm is crucial in the breakdown of the waste.
• Cytoplasm provides shape to the cell. It fills up the cells, thus enabling the organelles to remain in their position.
• The genetic material of bacteria is found in the cytoplasm in the form of nucleotide. Hence option 2 is correct.
• The cytoplasm is the material within a living cell, excluding the cell nucleus. 
• All of the contents of the cells of prokaryotic organisms are contained within the cytoplasm.

Key Points

• Darwin proposed a theory of evolution called natural selection in the year 1859. According to it those populations which are a better fit (reproductively fit) in an environment will be selected by nature and will survive more.
• Darwin conducted a sea voyage in a sailing ship called H.M.S Beagle as a part of his experiments on the theory of evolution.
• Charles Darwin concluded that existing living forms share similarities to varying degrees not only among themselves but also with life forms that existed millions of years ago
• Darwin's theory of natural selection is popularly known as 'Darwinism'.
• The evolution by natural selection, in a true sense, would have started when cellular forms of life with differences in metabolic capability originated on earth.
• Darwin went to the Galapagos Islands during his journey.
• Branching descent and natural selection are the two key concepts of Darwinian Theory of Evolution
• The process of evolution of different species in a given geographical area starting from a point and literally radiating to other areas of geography (habitats) is called adaptive radiation.
• Darwin’s finches represent one of the best examples of adaptive radiation.

Important Points

• Charles Darwin is known as the father of ''Evolutionary Biology''.

Additional Information

• According to Lamarck, the evolution of life occurred due to the use and disuse of organs.
• Gregor Mendel proposed the law of heredity through his work on pea plants and discovered the fundamental laws of laws of inheritance. . 
• Weismann gave the theory of Continuity of Germplasm

The correct answer is Gene.

• Gene is a part of DNA, which provides information for a protein.

Key Points

• Genes are functional units of heredity as they are made of DNA. The chromosome is made of DNA containing many genes.
  • Every gene comprises a particular set of instructions for a particular function or protein-coding. Speaking in usual terms, genes are responsible for heredity.
  • There are about 30000 genes in each cell of the human body. DNA present in the gene comprises only 2 percent of the genome.
  • Many studies have been made on the same that found the location of nearly 13000 genes on each of the chromosomes.

Important Points

• William Bateson introduced the term genetics in the year 1905.
  • Wilhelm Johannes was the first one who coined the term GENE in 1909.
  • He was a Danish botanist.
  • He named it Gene to symbolize hereditary.