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Biology µGCSE:

Inheritance Terminology

10 quick questions - for GCSE and iGCSE



10 minutes maximum! (can you do it in 5?)

1+2: The diagram shows a gamete. The nucleus contains 16 chromosomes:


1. What is the diploid number of this organism?
  • A. 16                  
  • B. 32
  • C. 8
  • D. 46   
2.What is the haploid number of this organism?
  • A. 16                  
  • B. 32
  • C. 8
  • D. 46
3-5: Fruit flies are often found around bananas. They can have either white or red eyes. Red is dominant to white.

male reproductive system

A red eyed parent fly RR was crossed with a white eyed parent fly rr.
All the offspring had red eyes.

Hannah Davies | CC 4.0
3.What is the geneotype of the offspring?
  • A. RR
  • B. Rr
  • C. Red
  • D. rr

4. The white eyed parent is said to be

  • A. Heterozygous
  • B. Homozygous recessive
  • C. Homozygous dominant
  • D. Hybrid

5. The heterozygous red eyed offspring were crossed with each other.

  R r
R ? ?
r ? ?
What is the probability that there will be white eyed offspring?
  • A. 0
  • B. 50%
  • C. 25%
  • D 100%

6-8: The photograph shows some pea pods on a pea plant.

Mendel investigated the genetics of pea plants.
He cross pollinated the flowers of homozygous tall plants with those of homozygous dwarf plants. He planted the seeds that formed and found all the plants grew into tall plants. This is the first generation.
He then self-pollinated all these plants and found that the seeds from these plants produced both tall and dwarf plants. This is the second generation.

male reproductive system
Rasbak | CC 3.0

6. What controls the height of the plant?
  • A. gene
  • B. nucleus
  • C. chromosome
  • D. fertilizer
7. If T represents the allele for the tall plants and t the allele for dwarf plants what is the phenotype and genotype of the 1st generation?
  • A. Tall TT
  • B. Tall Tt
  • C. Dwarf Tt
  • D. Dwarf tt
8. If Mendel collected and planted 100 seeds produced from the self-pollination of the 1st generation, on average how many of the seeds would he expect to grow into tall plants?
  • A. 0
  • B. 25
  • C. 50
  • D. 75

9+10: A male brown mouse was mated with a female brown mouse and the coat colour of their offspring is shown in the diagram.

mouse genetics diagram

9. What is the most probable reason that the 2 brown haired parents produced a black-haired offspring?
  • A. Both parents are heterozygous for hair colour
  • B. The black coat colour was due to an environmental factor, such as air pollution.
  • C. There had been a change in the alleles causing the black colour
  • D. The mother mouse had mated with a different father.

10. The black mouse was mated with the brown parent as shown:

mouse genetics diagram 2

What are the likely offspring?

  • A. All brown
  • B. All black
  • C. 50% Brown 50% black
  • D. 25% Black 75% brown