Selection and Variation

The graph shows the percentage of a population of plants with a given number of flowers. What type of variation is the number of flowers?

• Continuous

• Discontinuous

A group of scientists want to investigate the effect of different soil conditions on plant growth. They cloned a plant to get a total of 7 plants and grew them in different nitrate concentrations for 14 days.They then repeated this with a different species of plant. The table given shows their results. The scientists cloned the plants so they were genetically identical. Which of the following best explains why this was important?

• Because the plants would all grow the same amount

• Because any changes in growth would be due to environmental variation alone

• Because any changes in growth would be due to genetic variation alone

• Because the plants all looked the same

Which of the following conclusions is correct, based on the data given?

• Plant growth is due to genetic and environmental factors.

• Plant growth is due to environmental factors alone.

• Plants of the same species will grow the same amount, no matter where they are grown.

• Plant growth is due to genetic factors alone.

Give the correct key term for the differences in the characteristics of organisms.

• Variation

• Phenotypes

• Genotypes

Give the correct key term for the variation that is caused by differences in alleles that are inherited or caused by mutations.

• Genetic variation

• Generic variation

• Mutagenic variation

Variations in the stem length can be caused by mutations. Which of the following correctly defines mutations?

• Changes in the phenotype

• Changes in the DNA base sequence

• A section of DNA that codes for a protein

Horse breeding for specific desired traits is an example of which type of evolutionary evidence?

• Artificial selection

• Embryology

• Fossils

• Biochemical molecules

Individuals that are well adapted to their environment will survive and produce:

• Fewer mutations

• Stronger genes

• More offspring

• Better traits

Predict which moth would increase in population:

• light

• dark

Which organisms are most likely to survive?

• the best adapted
• the fastest
• the strongest
• the most domesticated (tamed)