Higher Biology Unit 3 - Key Area 2

Identify the key term that refers to individuals having two identical alleles for the same gene.

• Heterozygous

• Homozygous

• Dominant

• Inbreeding

Identify the key term that refers to individuals having two different alleles for the same gene.

• Heterozygous

• Homozygous

• Dominant

• Inbreeding

Identify the key term that refers to crossing organisms that are related for several generations until the population breeds true to the desired phenotype.

• Heterozygous

• Homozygous

• Dominant

• Inbreeding

Identify the key term that refers plants produced by crossing two different inbred lines.

• F₁ Generation

• F₂ Generation

• F₁ Hybrid

When designing a field trial, which of the following will not increase the validity of the results?

• Randomisation of treatments

• Selection of treatments

• Number of replicates

• Cost of the treatment

Which of the following descriptions below apply to inbreeding?

1. increases genetic variation in offspring.

2. mating distantly related individuals

3. offspring likely to have a reduced biological fitness.

4. reduces genetic variation in offspring.

• 1 and 2

• 1 and 4

• 2 and 4

• 3 and 4

The field trial was set up to investigate the effect of mass of fertiliser applied and the application of fungicide on the growth of barely. The diagram shows the distribution of plots in the field and the treatments applied.

Which design feature was included to eliminate bias?

• Application of 3 different masses of fertiliser

• Randomisation of treatments

• Use of 3 replicates

• Application of fungicide to half the plots.

The reason for replicating treatments during plant field trials is to

• Develop improved plant varieties

• Ensure fair comparison between treatments

• Take into account the variability within the plants being grown.

• eliminate bias when measuring the effects of treatments groups.

Inbreeding depression is a result of

• An increase in heterozygotes

• A genetically variable population

• Crossbreeding of recessive characteristics

• An accumulation of recessive deleterious alleles.

Which of the following is a consequence of inbreeding over many generations?

• Increased yield and increased disease resistance

• Decreased yield and decreased size

• Decreased yield and increased size