LS3 - Unit Test Review

Kioshi and Raidon are brothers. Both of their parents have brown eyes. Kioshi also has brown eyes but Raidon's eyes are grey. Which of the following explains why the brothers have different eye color?

• Parents who both have brown eyes always have at least one offspring with grey eyes.

• Offspring from the same parents always inherit the same traits.

• Sometimes an offspring can show a variation of a trait that neither parent has.

• Eye color is not an inherited trait

Caitrin and Fiona are identical twin girls. You learned that this means they have the same DNA that carries the same set of instructions for traits. Examine the chart of the girls' characteristics. If they are identical twins, what can explain the differences in traits?

• Their DNA is different.

• Their traits were influenced by the environment.

• There is not enough information.

Examine the pedigree. Which of the following statements best fits the data?

• Two parents with widow's peaks only have widow's peak children.

• Two parents with no widow's peak only have children with no widow's peak.

• If parents do not match on the widow's peak trait, the children will all have no widow's peak.

• If parents do not match on the trait, the children will all have widow's peak.

Felicia, Maria, and Louis are siblings. Felicia is the oldest and Louis is the youngest. Maria is in the middle. How much of their genetic information will they have in common?

• They all have exactly the same information because they have the same mother and father.

• Maria and Felicia share the same information but not Louis.

• They have no genetic information in common because they are not triplets.

• They share about 50% of their genetic information with each of the other siblings.

Hector was doing some experiments with plants. The plants have two variations of the flower color - pink or white. He used pollen from one plant and fertilized another plant. He noticed that sometimes when he crossed two plants with pink flowers, some offspring had white flowers. What can explain this?

• A mutation occurred

• The plants carry the genotype for only pink flowers.

• The plants carry the genotype for both white and pink flowers.

• There is not enough information

Huntington's disease affects the muscles and nervous system. People who have Huntington's usually get the disease in their 30s. Which of the following is the most accurate statement?

• Huntington's disease could not be due to genetics because genes determine your inherited traits from birth and they do not change in your 30s.

• Huntington's disease could not be due to genetics because everyone's internal organs are the same.

• Huntington's disease could be due to genetics because a slight change in a gene you are born with produces an abnormal protein that eventually leads to a disease.

• Huntington's disease could be due to genetics because most diseases that affect the nervous system are due to genetics.

When you get a prescription for antibiotics, the label states that you have to keep taking it even after you start to feel better. Why is it important to take the full dose of antibiotics? Choose the best answer

• You should always finish all of your prescriptions because you may not be fully recovered yet and you could get sick again if you stop the antibiotic.

• Bacteria vary in how easily they are killed by the antibiotic. Some bacteria may die more quickly, and the ones that are tougher will multiply.

• The antibiotic may make you feel better before all the bacteria are killed, and the ones still alive may make you sick again after you stop the antibiotic.

• It can take a long time to get to all the bacteria in your body, so you need to keep the dose high until all the remaining bacteria have been killed.

Nick conducted an investigation using young tomato plants grown in a greenhouse. All of the plants were the same species and, at the start of the investigation, the same size. Some of the tomato plants in the greenhouse were shaded. Other plants, forming a control group, were in sunlight. The number of plants per square meter of soil were the same for both groups. Over a period of 90 days, some plants from each group were harvested, and then dried to provide a more accurate measure of growth. The dry mass of tomato plants per square meter of soil was measured for both groups. The table shows the data from Nick's investigation. Based on this evidence, which statement best explains the differences in the growth of the two groups of tomato plants?

• Being shaded produces nutrients inside tomato plants that cause growth when sunlight is absent.

• Being shaded turns on growth genes inside tomato plants that cause the plants to make more stems and leaves.

• Exposure to sunlight helps tomato plants to reproduce more quickly, which increases the number of plants per square meter.

• Exposure to sunlight increases the rate of photosynthesis in tomato plants, which helps provide materials for plants to grow.

Many supermarkets sell wild-caught salmon and farm-raised salmon. The salmon raised in fish farms are often genetically modified to resist disease and to grow faster than wild salmon. The graph shows the amount of salmon caught in the wild, the amount raised in fish farms, and the total amount of both over a 20-year period. Which statement best describes the data presented in the graph?

• In 2010, most of the salmon available in supermarkets was genetically modified.

• Since 1990, humans have preferred the taste of genetically modified salmon to that of wild-caught salmon.

• Humans have caught too many wild salmon and now have to rely on genetically modified salmon for food.

• The business of catching wild salmon has decreased as a result of the increase in popularity of genetically modified salmon.

Zach uses an amoeba in a model of asexual reproduction. The first two steps of Zach's model are shown. Which statement best explains what the final step of Zach's model will be?

• two amoebas each with half of the original genetic information, because the nucleus divides in two

• one large amoeba with two copies of identical information, because the genetic material is copied in reproduction

• two amoebas with identical genetic information, because each receives a complete copy from the same parent cell

• four amoebas each with half of the original genetic information, because each will join with another amoeba to create a new organism