MDCAT Biology Inheritance Test Online MCQs

MDCAT Biology Inheritance Test

MDCAT Biology preparation with this focused online MCQ test on Inheritance. Covering topics like Mendel’s laws, gene linkage, crossing over, and sex-linked traits, this quiz is based on the updated MDCAT 2025 syllabus to help you master the principles of heredity.

MDCAT 2025 Inheritance Online Test

Inheritance MCQS Online Question with Answer

Please wait...

 0%

Page 1 of 2

1. Which of the following is an example of a dihybrid trait?

Flower color in pea plants

Height in pea plants

Blood type in humans

Height and seed shape in pea plants

 Loading...

2. What is the condition in which an individual has two identical alleles for a trait?

Diploid

Homozygous

Heterozygous

Hybrid

 Loading...

3. Hemophilia primarily affects:

Blood clotting

Digestive system

Muscle strength

Nerve function

 Loading...

4. A female with normal genes for clotting marries a hemophilic man. What is the chance their son will have hemophilia?

0%

25%

100%

50%

 Loading...

5. A carrier female for hemophilia would have the genotype:

XʰX

XX

XʰXʰ

XY

 Loading...

6. How many alleles does a diploid organism have for each gene?

One

Three

Four

Two

 Loading...

7. Which of the following is a test cross?

Tt × tt

TT × TT

TT × Tt

Tt × Tt

 Loading...

8. Which of the following would have a 100% chance of passing on an X-linked recessive trait to daughters?

Carrier mother

Carrier father

Affected father

Normal mother

 Loading...

9. A recessive allele is expressed only when:

It is present on a Y chromosome

It is present on both homologous chromosomes

It is on a heterozygous genotype

It is dominant over another allele

 Loading...

10. Which term refers to different forms of a gene?

Chromatids

Traits

Nucleotides

Alleles

 Loading...

11. Which process leads to genetic recombination?

Translation

Mitosis

Replication

Crossing over

 Loading...

12. Which scientist is known as the father of genetics?

Watson

Lamarck

Mendel

Darwin

 Loading...

13. Which term describes genes located on the same chromosome and inherited together?

Alleles

Codominant genes

Recessive genes

Linked genes

 Loading...

14. In X-linked inheritance, who can be carriers of the trait?

Only females

Both males and females

Only males

Neither

 Loading...

15. What process can separate linked genes?

Transcription

Replication

Crossing over

Translation

 Loading...

16. If two carriers of a recessive disorder marry, what is the chance their child will be affected?

25%

0%

50%

100%

 Loading...

17. In Mendel's dihybrid cross, what phenotypic ratio is expected in the F2 generation?

1:1

3:1

9:3:3:1

1:2:1

 Loading...

18. Which of the following diseases is caused by an X-linked recessive gene?

Cancer

Diabetes

Sickle-cell anemia

Hemophilia

 Loading...

19. Gene linkage occurs when:

Genes are silenced

Genes code for the same protein

Genes are located close together on the same chromosome

Genes are located on different chromosomes

 Loading...

20. Which of the following crosses would show Mendel’s Law of Independent Assortment?

TT × Tt

TtRr × TtRr

Tt × tt

TT × tt

 Loading...

21. Sex-linked genes are mostly located on:

X chromosome

Mitochondrial DNA

Autosomes

Y chromosome

 Loading...

22. What is the result of crossing TT (tall) with tt (short) pea plants?

50% tall, 50% short

All medium

All short

All tall

 Loading...

23. A male inherits his X chromosome from:

Only from autosomes

Both parents

His mother

His father

 Loading...

24. Why are X-linked recessive traits more common in males?

Males have only one X chromosome

Y chromosome protects them

Males are more prone to mutations

Males have two X chromosomes

 Loading...

25. What is the probability that a carrier mother and a normal father will have a son with hemophilia?

25%

0%

50%

100%

 Loading...

Page 2 of 2

26. Which of the following is a result of gene linkage?

Random recombination

Traits assort independently

Inherited traits appear together

Greater genetic variation

 Loading...

27. What does the Law of Independent Assortment explain?

Each pair of alleles segregates independently during gamete formation

Mutations occur randomly

Dominant traits hide recessive ones

Alleles always segregate together

 Loading...

28. Which phase of meiosis does crossing over occur?

Anaphase II

Metaphase I

Prophase I

Telophase I

 Loading...

29. A hemophilic male and a carrier female have how many chances of passing on the disease?

100%

75%

25%

50%

 Loading...

30. What is the significance of independent assortment?

It increases the number of cells

It ensures mutation

It maintains genetic stability

It increases genetic variation

 Loading...

31. What does a test cross help determine?

The blood group

Whether an individual is heterozygous or homozygous dominant

The presence of recessive traits only

The number of chromosomes

 Loading...

32. If T is dominant for tall and t for dwarf, what is the phenotype of Tt?

Medium height

Tall

Dwarf

Recessive

 Loading...

33. The units of inheritance are:

Chromosomes

Ribosomes

Genes

Proteins

 Loading...

34. In a Punnett square of an XʰX × XY cross, what is the chance of a daughter being a carrier?

100%

25%

0%

50%

 Loading...

35. What is the expected genotypic ratio of a monohybrid cross between two heterozygotes?

1:2:1

1:1

9:3:3:1

3:1

 Loading...

36. Which of the following violates the law of independent assortment?

Codominance

Mutation

Gene linkage

Crossing over

 Loading...

37. Which of the following best defines crossing over?

Random mutation of DNA

Segregation of alleles during mitosis

Exchange of segments between non-sister chromatids of homologous chromosomes

Exchange of genetic material between sister chromatids

 Loading...

38. In hemophilia, a female must inherit:

One defective autosome

Two defective X chromosomes

One defective X

One defective Y

 Loading...

39. In Mendel’s experiments, which trait was dominant?

Tall stem

White flower

Wrinkled seeds

Short stem

 Loading...

40. How many types of gametes can be produced by a heterozygous dihybrid individual (TtRr)?

1

8

2

4

 Loading...

41. What does heterozygous mean?

Having a dominant trait only

Having two identical alleles

Having different alleles

Having one allele

 Loading...

42. What is the effect of crossing over on linked genes?

May separate them, increasing variation

Prevents their expression

Ensures they always remain linked

Has no effect

 Loading...

43. What is the purpose of a Punnett square?

To identify dominant alleles

To determine the age of a gene

To predict the probability of genetic traits

To study chromosomes under a microscope

 Loading...

44. Which of the following terms best describes the physical appearance of an organism?

Phenotype

Karyotype

Genotype

Allele

 Loading...

45. In which sex is hemophilia most commonly expressed?

Both equally

Males

Only children

Females

 Loading...

46. Why can’t fathers pass X-linked traits to sons?

Sons reject X chromosomes

Sons don’t have X chromosomes

Fathers don’t carry defective genes

Fathers only pass the Y chromosome to sons

 Loading...

47. What is gene mapping based on?

Frequency of crossing over

Physical size of chromosomes

Location of traits

Shape of DNA

 Loading...

48. Which of the following best describes Mendel's Law of Segregation?

Traits are inherited in pairs

Genes always blend in offspring

Dominant traits are always expressed

Alleles for a trait separate during gamete formation

 Loading...

 Loading...

• <<
• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
• 10
• 11
• 12
• 13
• 14
• 15
• 16
• 17
• 18
• 19
• 20
• 21
• 22
• 23
• 24
• 25
• 26
• 27
• 28
• 29
• 30
• 31
• 32
• 33
• 34
• 35
• 36
• 37
• 38
• 39
• 40
• 41
• 42
• 43
• 44
• 45
• 46
• 47
• 48
• >>