Heredity And Evolution : Test 1 - Class 10 MCQ

The process where characteristics are transmitted from parent to offspring is called:

Heredity

Heredity is the process by which traits or characteristics are passed down from parents to their offspring. It involves the transmission of genetic information from one generation to the next.

Key points about heredity:

• Heredity is a fundamental principle of biology that explains how traits are inherited.


• It involves the passing of genetic information, contained in genes, from parents to their offspring.


• Genes are segments of DNA that contain instructions for the development and functioning of organisms.


• During the process of reproduction, genetic material is passed on through the gametes (sperm and egg cells).


• Offspring inherit a combination of genes from both parents, which determine their traits and characteristics.


• Heredity is responsible for the similarities and differences observed between individuals within a species.


• It plays a crucial role in evolution, as genetic variations can lead to the emergence of new traits and species over time.

Therefore, heredity is the correct answer to the question.

Variation
- Variation refers to the differences in characteristics exhibited by individuals of a species.
- It is a fundamental aspect of biological diversity and plays a crucial role in the process of evolution.
- Variation can be observed in various traits such as physical appearance, behavior, and genetic makeup.
- It is a result of genetic and environmental factors that influence the development and expression of traits.
- Variation provides the raw material for natural selection to act upon, leading to the adaptation and evolution of species.
- It allows individuals to be better suited to their environment and increases their chances of survival and reproduction.
- Variation can be classified into two types: heritable variation (passed on through genes) and non-heritable variation (influenced by the environment).
- The study of variation is essential for understanding the mechanisms underlying evolutionary processes and the maintenance of biodiversity.
Therefore, the correct answer is C: Variation.

Which of the following statements is Incorrect?

The incorrect statement is D: Genes cannot acquire mutations in their sequence.
Explanation:
Statement A: Gene is a sequence of nucleotides
- This statement is correct. A gene is a specific sequence of nucleotides (DNA or RNA) that contains the genetic instructions for the development, functioning, and reproduction of living organisms.
Statement B: During the process of gene expression, DNA is first copied into RNA
- This statement is correct. The process of gene expression involves the transcription of DNA into RNA, which is then translated into proteins.
Statement C: Genes can acquire mutations in their sequence
- This statement is correct. Mutations are changes in the DNA sequence, and genes are made up of DNA. Mutations can occur naturally or as a result of environmental factors, and they can lead to changes in the function or expression of genes.
Statement D: Genes cannot acquire mutations in their sequence
- This statement is incorrect. As mentioned in statement C, genes can acquire mutations. Mutations in genes can have various effects, ranging from no significant impact to causing genetic disorders or diseases.
In summary, statement D is the incorrect statement because genes can indeed acquire mutations in their sequence.

Phenotype is the observable set of characteristics of an organism.
Explanation:
Phenotype refers to the physical and observable traits of an organism, which are influenced by both genetic and environmental factors. It is determined by the expression of genes and their interaction with the environment. Here is a detailed explanation:
Phenotype:
- Phenotype is the physical and observable characteristics of an organism, such as its appearance, behavior, and physiological traits.
- It includes traits like hair color, eye color, height, weight, and susceptibility to certain diseases.
- The phenotype is the result of the interaction between an organism's genetic makeup (genotype) and the environment.
Genes:
- Genes are segments of DNA that contain instructions for the development and functioning of an organism.
- They determine the genetic traits and potential characteristics of an organism.
- Genes are responsible for the inheritance of traits from parents to offspring.
DNA:
- DNA (Deoxyribonucleic Acid) is a molecule that carries the genetic instructions for the development and functioning of all living organisms.
- It contains the genetic code that determines the characteristics of an organism.
- DNA is made up of nucleotide bases (adenine, thymine, cytosine, and guanine) and is organized into chromosomes.
All of the above:
- The correct answer is "a." Phenotype because it specifically refers to the observable set of characteristics of an organism.
- While genes and DNA play a crucial role in determining an organism's phenotype, they are not the same as phenotype itself.
In conclusion, the observable set of characteristics of an organism is referred to as its phenotype. It is influenced by both genetic factors (genes) and environmental factors. DNA contains the genetic information that determines an organism's phenotype, but it is not the same as phenotype itself.

Explanation:
Cross-pollination:
- Cross-pollination is the transfer of pollen from the anther of one flower to the stigma of another flower of the same species.
- It occurs between different varieties of the same plant species.
Newly formed plant:
- When cross-pollination occurs, the result is the formation of a new plant.
- This new plant possesses characteristics and traits from both parent plants.
Terminology:
- The term used to describe the newly formed plant is "hybrid plant."
Hybrid plant:
- A hybrid plant is the offspring of two different varieties of the same plant species.
- It exhibits a combination of characteristics from both parent plants.
- The purpose of creating hybrid plants is to obtain plants with desirable traits such as increased yield, disease resistance, or specific flower colors.
Other options:
- "Dominant plant" and "mutant plant" are incorrect options.
- A dominant plant refers to a plant that exhibits dominance in terms of traits over other plants in a population.
- A mutant plant refers to a plant that has undergone a mutation, resulting in a change in its genetic makeup.
Conclusion:
- When a new plant is formed as a result of cross-pollination from different varieties of a plant, the newly formed plant is called a "hybrid plant."