biology MCQs - 10th class Chapter 06 Mcqs

1

The branch of biology in which we study inheritance is called what?

A

Anatomy

B

Physiology

C

Genetics

D

Evolution

2

The transmission of characteristics from parents to offspring is known as:

A

Variation

B

Inheritance

C

Mutation

D

Selection

3

The characteristics that are transmitted from parents to offspring are called:

A

Genes

B

Alleles

C

Traits

D

Chromosomes

4

The units of inheritance, which are carried on chromosomes, are called:

A

Nucleosomes

B

Genes

C

Proteins

D

Histones

5

How many total chromosomes are found in a normal human body cell?

A

23

B

46

C

48

D

92

6

The pair of chromosomes with the same size and shape are known as:

A

Sister chromatids

B

Homologous chromosomes

C

Gametes

D

Zygotes

7

Chromatin is a complex material made of DNA and what type of proteins?

A

Enzymes

B

Antibodies

C

Histone proteins

D

Structural proteins

8

DNA wraps around histone proteins to form round structures called:

A

Chromatids

B

Centromeres

C

Nucleosomes

D

Loci

9

Who proposed the double helix structure for DNA in 1953?

A

Gregor Mendel

B

Charles Darwin

C

Watson and Crick

D

R. C. Punnett

10

According to the Watson-Crick model, a DNA molecule consists of how many polynucleotide strands?

A

One

B

Two

C

Three

D

Four

11

In the DNA double helix, which nitrogenous base pairs with Adenine?

A

Guanine

B

Cytosine

C

Uracil

D

Thymine

12

How many hydrogen bonds are formed between Cytosine and Guanine?

A

One

B

Two

C

Three

D

Four

13

The process where a DNA molecule is duplicated before a cell divides is called:

A

Transcription

B

Translation

C

Replication

D

Mutation

14

The process of copying the genetic sequence from DNA to messenger RNA (mRNA) is known as:

A

Translation

B

Replication

C

Transcription

D

Segregation

15

Which cellular structure reads the mRNA sequence to synthesize proteins?

A

Nucleus

B

Mitochondrion

C

Ribosome

D

Lysosome

16

A specific sequence of DNA nucleotides that contains instructions for a particular protein is a:

A

Gene

B

Allele

C

Locus

D

Genotype

17

The specific locations or positions of genes on chromosomes are known as:

A

Alleles

B

Loci

C

Centromeres

D

Telomeres

18

The alternate forms of a gene are called:

A

Genotypes

B

Phenotypes

C

Loci

D

Alleles

19

A genotype in which the gene pair contains two identical alleles (e.g., AA or aa) is called:

A

Heterozygous

B

Dominant

C

Recessive

D

Homozygous

20

A genotype in which the gene pair contains two different alleles (e.g., Aa) is called:

A

Homozygous

B

Recessive

C

Heterozygous

D

Dominant

21

In a heterozygous condition, the allele that masks the expression of the other is called:

A

Recessive

B

Dominant

C

Co-dominant

D

Mutated

22

The physical expression of a genotype in the form of a trait is known as the:

A

Genotype

B

Allele

C

Phenotype

D

Locus

23

Gregor Mendel conducted his foundational experiments on which organism?

A

Fruit flies

B

Mice

C

Pea plants

D

Four 'O' Clock plants

24

A cross in which only one trait is studied at a time is called a:

A

Dihybrid cross

B

Test cross

C

Monohybrid cross

D

Back cross

25

In Mendel's monohybrid crosses, what was the approximate phenotypic ratio in the F2 generation?

A

1:1

B

1:2:1

C

3:1

D

9:3:3:1

26

Which of Mendel's laws states that alleles of a gene pair separate from each other during gamete formation?

A

Law of Dominance

B

Law of Independent Assortment

C

Law of Segregation

D

Law of Variation

27

A cross involving two different traits, such as seed shape and seed colour, is known as a:

A

Monohybrid cross

B

Dihybrid cross

C

Test cross

D

Reciprocal cross

28

What is the phenotypic ratio of a classic Mendelian dihybrid cross in the F2 generation?

A

3:1

B

1:2:1

C

9:3:3:1

D

1:1:1:1

29

Which diagram is used to predict the outcome of a particular genetic cross?

A

Pedigree chart

B

Karyotype

C

Punnett square

D

Flow chart

30

The situation where two different alleles of a gene pair both express themselves completely is called:

A

Incomplete dominance

B

Recessive expression

C

Co-dominance

D

Mutation

31

The human ABO blood group system is a classic example of:

A

Incomplete dominance

B

Co-dominance and multiple alleles

C

Polygenic inheritance

D

Simple dominance

32

In the ABO system, which genotype results in blood group AB?

A

IAIA

B

IAi

C

ii

D

IAIB

33

In Four 'O' Clock plants, a cross between red (RR) and white (rr) flowered plants produces pink (Rr) offspring. This is an example of:

A

Co-dominance

B

Incomplete dominance

C

Segregation

D

Independent assortment

34

What is the phenotypic ratio when two pink (Rr) Four 'O' Clock plants are crossed?

A

3:1

B

9:3:3:1

C

All pink

D

1:2:1

35

Which of the following is a primary source of genetic variation?

A

Mitosis

B

Asexual reproduction

C

Mutations

D

Cloning

36

Variations that show a complete range of measurements from one extreme to the other, like human height, are called:

A

Discontinuous variations

B

Continuous variations

C

Mutations

D

Allelic variations

37

Blood groups in humans, which have distinct phenotypes (A, B, AB, O), are an example of:

A

Continuous variation

B

Discontinuous variation

C

Environmental variation

D

Polygenic traits

38

Who first proposed the mechanism of evolution called 'Natural Selection'?

A

Gregor Mendel

B

J. de Lamarck

C

C. de Buffon

D

Charles Darwin

39

In evolutionary terms, an organism's ability to survive and reproduce is called its:

A

Strength

B

Fitness

C

Adaptation

D

Variation

40

The case of the peppered moths in England during the Industrial Revolution illustrates:

A

Artificial selection

B

Genetic drift

C

Natural selection

D

Speciation

41

The intentional breeding of individuals for certain traits by humans is known as:

A

Natural selection

B

Artificial selection

C

Random mating

D

Gene flow

42

Animals that have been bred through artificial selection for specific traits are known as:

A

Cultivars

B

Species

C

Breeds

D

Genera

43

Varieties of plants produced through selective breeding are also known as:

A

Breeds

B

Clones

C

Hybrids

D

Cultivars

44

Broccoli, cabbage, and cauliflower were all produced by artificial selection from which plant?

A

Wild mustard

B

Wild pea

C

Wild rose

D

Wild wheat

45

What controls the synthesis of specific proteins in a cell?

A

RNA

B

Ribosomes

C

Enzymes

D

DNA

46

A human gamete (sperm or egg) contains how many chromosomes?

A

46

B

23

C

47

D

22

47

According to Mendel, the trait for round seeds in pea plants is dominant over:

A

Yellow seeds

B

Green seeds

C

Wrinkled seeds

D

Tall plants

48

The allele 'i' for blood group O is what in relation to alleles IA and IB?

A

Dominant

B

Co-dominant

C

Recessive

D

Incompletely dominant

49

Which process happens first in the 'Central Dogma' of molecular biology?

A

Replication

B

Translation

C

Transcription

D

Mutation

50

Changes in the genetic characteristics of a population over generations is called:

A

Genetics

B

Development

C

Organic evolution

D

Artificial selection