STAAR REVIEW (2013 Test)

What does the projections of a virus help it to do?

• Attach onto a HOST cell

• Attach onto a VIRAL cell

• Stick to surfaces (NOT LIVING)

Answer explanation

Remember: A Virus NEEDS a HOST cell to survive

IF an island was formed by a volcanic eruption, from the descriptions below, please put the events in order.

1: Sea Lyme grass, sea rockets, oyster plants, and other vascular plants appear

2: The lava and sands have few nutrients and are barren.

3: Dwarf willow trees colonize the island.

4: Mosses, lichens, and plants that are adapted to dispersal by the sea or the wind and that grow in sand appear

• 1, 2, 3, 4

• 4, 3, 2, 1

• 2, 4, 1, 3

• 4, 3, 1, 2

Answer explanation

This is a secondary succession since soil is present from a volcano

Having a standard taxonomic system benefits the scientific community by allowing scientists from all over the world to do which of the following?

(Eliminate those that DO NOT have anything to do with the taxonomic system)

• Have a common system for the classification of locations containing fossils

• Use a similar system to classify the impact of removing species from ecosystems

• Have a common understanding in the classification of organisms

• Understand how other scientists classify predator–prey relationships

Answer explanation

The taxonomic system is remembered as Dear King Phillip Came Over For Great spaghetti OR Dear Katy Perry Came Over For Great Spaghetti

This system helps to classify organisms

Health-care workers are exposed to many different types of pathogenic and non-pathogenic microorganisms. Which body systems work together to protect the body from pathogens?

• Circulatory and Integumentary

• Immune and Circulatory

• Muscular and Vascular

• Endocrine and Reproductive

Answer explanation

Immune: Helps body fight infections

Circulatory: Filters blood and removes wastes from blood/body

Which of these statements best explains the process of energy conversion that takes place in the mitochondria?

• Energy is required for carbon dioxide molecules to form six-carbon sugar molecules.

• Water molecules and radiant energy are necessary for anaerobic respiration to take place.

• Oxygen molecules release energy in the form of heat during combustion reactions.

• The energy in the bonds of glucose molecules is transferred to the phosphate bonds in ATP.

Answer explanation

Mitochondria is where ATP energy is formed

Leaves are part of a plant’s shoot system. The xylem tissue in leaves transports —

• the bacteria needed for nitrogen fixation in root nodules

• the wax required to coat the surface of actively growing tissue

• the water and minerals that are absorbed by the roots

• the oxygen that regulates the rate of carbohydrate production

Answer explanation

Xylem deals with Water and nutrients

Some organisms have genes that improve their ability to survive and reproduce. If the genes also help their offspring survive and reproduce, then which of the following will most likely increase?

• The frequency of the genes in one individual

• The frequency of the genes in the population

• The number of genes in one chromosome

• The number of genes in the species

The overgrowth of algae poses a major problem for coral reefs. Intensive fishing is one factor that contributes to algae overgrowth because it does which of the following?

• Allows more sunlight to be available to algae

• Inhibits the spread of pathogens in algae colonies

• Reduces the number of organisms that feed on algae

• Increases the competition between different algae species

Enzymes are proteins that help increase the rate of chemical reactions inside cells. These proteins are composed of many simpler molecules called amino acids. Which of the following suggests that the shape of an enzyme determines the enzyme’s function?

• Enzymes are specific to a substrate

• Enzymes can operate in a wide range of conditions.

• Enzymes are activated by neighboring molecules

• Enzymes can be found in all life-forms.

What is a complementary strand of DNA called?

• Proteins

• mRNA

• Polypeptide

• New DNA