Core 40 Practice Test Version C

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Multiple Choice

Identify the letter of the choice that best completes the statement or answers the question.

According to the picture above, energy flows from

a.	shark to algae.	c.	small fishes to zooplankton.
b.	squid to shark.	d.	zooplankton to algae.

Which of the following are not continuously recycled in an ecosystem?

a.	water.	c.	oxygen.
b.	nintrogen.	d.	energy

Which of the following best describes the source of genes in a baby resulting from sexual reproduction?

a.	Offspring receive DNA from both parents.	c.	The female parent is the source of all the genes.
b.	The male parent contributes the most chromosomes.	d.	Offspring inherit their traits from the dominant parent.

Which structure in the eukaryotic cell is thought to have developed from early prokaryotic cells, according to the endosymbiotic theory?

a.	vacuole	c.	mitochondrion
b.	lysosome	d.	Golgi apparatus

The progression of an ecosystem through various stages of development, often seen after a forest fire or a volcano, is referred to as

a.	regulation	c.	succession
b.	symbiosis	d.	transmission

The graph shows the frequency of mutant red blood cells (RBCs) to bone marrow radiation dose among atomic bomb survivors. What inference can be made about the relationship between mutant RBC frequency and exposure to radiation?

a.	Radiation causes cancer.	c.	Radiation produces RBC mutations.
b.	Radiation kills red blood cells.	d.	Radiation is released by mutant RBCs.

Which of the following is the role of decomposers in the nitrogen cycle?

a.	They add oxygen to atmospheric nitrogen.	c.	They help organisms absorb atmospheric nitrogen.
b.	They convert atmospheric nitrogen into ammonia.	d.	They release compounds that contain nitrogen into the soil.

Which of the following best describes the science ecology?

a.	the study of changes in populations over time	c.	The study of wildlife and wilderness conservation
b.	The study of the fossil record to determine genetic relationships	d.	The study of the interactions between organisms and their environment.

The tip of a plant seedling releases a substance that is transported to other parts of the plant causing an increase in the rate of cell growth and reproduction. What name is given to this type of chemical compound?

a.	pigment	c.	chlorophyll
b.	homone	d.	chromosomes

10.

Which of the following is the best example of homeostasis?

a.	In the United States, the average age of people marrying for the first time has increased over the last 30 years.	c.	People produce more red blood cells when they live in the reduced-oxygen conditions of high altitudes than when they live at sea level.
b.	An increase in pine and grass pollen frequencies suggests a short-lived, wet interval occurred around 2,500 years ago.	d.	Studies indicate wolves and coyotes differ by about 6% in their mitochondrial DNA-base sequences, while wolves and dogs differ by only 1%.

11.

During embryonic development, cells become specialized. What is this process called?

a.	oogenesis	c.	binary fission
b.	differentiation	d.	adaptive radiation

12.

Which structure regulates what enters and leaves the cell?

a.	cell wall	c.	cell membrane
b.	cytoplasm	d.	nucleolus

13.

Which of the following species is most likely to become extinct?

a.	a species with a narrow geographic range	c.	a species with a large population size
b.	a species with a high reproductive rate	d.	a species undergoing adaptive radiation

14.

Only mutations in sex cells can be passed on to an animal’s offspring, because mutations in body cells

a.	cause cancer	c.	are not inherited
b.	have no effect	d.	do not alter DNA

15.

What MUST be true of an organ donor and recipient?

a.	They must have identical DNA.	c.	They must share many behavioral characteristics.
b.	They must be the same age, race, and sex.	d.	They must share many of the same cell surface proteins.

16.

Which of the following is the MOST likely reason why one would introduce a non-native species into a new environment?

a.	to decrease the biodiversity of an area	c.	to decrease competition with a native species
b.	to add a new food source for consumers	d.	to add abiotic factors that benefit producers.

17.

Similarities in structure are often used as evidence of evolution. Figure 3 compares the hind limbs of Compsognathus, Archaeopteryx, and a modern bird. The similarities in these limbs show that they are

a.	homologous structures	c.	vestigial structures
b.	analagous structures	d.	embryonic structures

18.

According to Figure 4, an energy pyramid, with each step up an energy pyramid, how much energy is available for the next level?

a.	10%	c.	50%
b.	30%	d.	90%

19.

Which of the following BEST describes how vaccines work?

a.	Vaccines trigger white blood cells to stop making proteins.
b.	Vaccines activate immune cells to respond to a specific antigen.
c.	Vaccines prevent disease-causing agents from entering the body.
d.	Vaccines destroy foreign substances by increasing body temperature.

20.

Which of these structures is found in all prokaryotic and eukaryotic cells?

a.	ribosome
b.	nucleus
c.	cell wall
d.	Golgi apparatus

21.

A couple is expecting their fourth child. Their first three children are girls. What is the probability their next child will be a girl?

a.	25%
b.	50%
c.	75%
d.	100%

22.

Plant growth is usually limited to the amount of available

a.	copper.
b.	magnesium.
c.	nitrogen.
d.	calcium.

23.

If the sequence of DNA shown in Figure 5 were transcribed into messenger RNA (mRNA), the mRNA sequence would be

a.	UCGGCUAAUUAA
b.	UAAUCGGCUAAU
c.	TAAUCGGCUAAU
d.	ATTAGCCGATTA

24.

The genetic code used to translate nucleotide sequences into amino acid sequences is essentially the same in all living things. This is one piece of evidence that

a.	living things share a common ancestor.
b.	nucleotides are the basic units of nucleic acids.
c.	peptide bonds connect amino acids together.
d.	living things require oxygen, water, and food.

25.

One advantage of crossing over during meiosis is that crossing over

a.	makes offspring healthier.
b.	increases the number of gametes.
c.	provides a source of genetic variation.
d.	allows gametes to have half the number of chromosomes.

26.

Natural disasters such as floods or earthquakes may reduce the size of a population. The few organisms that survive may survive because they are lucky, not because they are better adapted to their environment. After such an event, the gene pool of the surviving population would

a.	be dominated by the best genes.
b.	have less genetic variation than before.
c.	contain the genes of the fittest individuals.
d.	be representative of the original population.

27.

Palm oil and coconut oil have similar effects on the cardiovascular system. Which of the following is the MOST likely conclusion, based on the fact that the oils function similarly?

a.	They have nearly the same densities.
b.	They are found in equal abundance in nature.
c.	They are found in different parts of the world.
d.	They consist of molecules with comparable structures.

28.

When some birds get cold, they fluff up their feathers. This allows them to

a.	use behavior to increase metabolic rate.
b.	use insulation to maintain body temperature.
c.	decrease cell activity to conserve metabolic rate.
d.	increase calorie output to raise body temperature.

29.

Enzymes are examples of

a.	lipids.
b.	proteins.
c.	carbohydrates.
d.	nucleic acids.

30.

In many species, there can be considerable variation among individuals. In humans, most of these differences are the result of

a.	DNA sequences.
b.	bacterial infections.
c.	artificial selection.
d.	organelle distribution.

31.

What is the basic unit of life?

a.	cell
b.	organism
c.	molecule
d.	organelle

32.

According to Figure 6, which of the graphs represents a population that increases until it reaches equilibrium?

a.	Graph A
b.	Graph B
c.	Graph C
d.	Graph D

33.

All species are able to

a.	regulate internal temperature.
b.	transmit nerve signals between neurons.
c.	filter waste products from the bloodstream.
d.	pass genetic information to the next generatiopn.

34.

The process of speciation can proceed in many different ways. Which describes the process of speciation followed by long periods of stability?

a.	gradualism
b.	convergence
c.	puntuated equilibrium
d.	spontaneous generation

35.

The BEST indicator of wether a cell is prokaryotic or eukaryotic is the presence or absence of

a.	DNA
b.	ribosomes
c.	a cell membrane
d.	a nuclear membrane

36.

Which plant organelle converts light energy into chemical energy?

a.	Golgi apparatus
b.	ribosome
c.	chloroplast
d.	mitochondrion

37.

Heat and detergents can cause many proteins to denature or change shape. Why does changing the shape of an enzyme often cause it to be LESS biologically active?

a.	There is less energy in the form of ATP.
b.	Genes that encode proteins have mutated.
c.	Substrate molecules may not fit inot the active site.
d.	Absence of end products slows down reaction rates.

38.

In 1983 a feline virus swept through an Oregon breeding facility for large cats. About 50% of the cheetahs died from the virus, but none of the lions died. Which of the following statements provides the BEST possible explaination for the difference in the cheetah and lion survival rates?

a.	Cheetahs are closely related to lions.
b.	Cheetahs have less genetic variation than lions.
c.	Cheetahs are less adapted to Oregon than are lions.
d.	Cheetahs are an endangered animal, and lions are not.

39.

Why are scientists concerned about the condition of the ozone layer in the upper atmosphere?

a.	Ozone levels are linked to a rise in birth defects in humans.
b.	Ozone causes dryness of the mouth and breathing difficulties.
c.	Ozone is a greenhouse gas and increases the rate of global warming.
d.	Ozone protects Earth by absorbing ultraviolet radiation from the sun.

40.

Fats and oils are types of

a.	lipids.
b.	proteins.
c.	nucleic acids.
d.	carbohydrates.

41.

Which of the following statements BEST describes how natural selection works within a given population?

a.	Individuals develop new survival adaptations as selective pressures force change.
b.	Individuals inherit variations that alter their chances of survival as selective pressures change.
c.	Individuals use different parts of their body as conditions change, and pass what they learn to offspring.
d.	Individuals change their behavior to adjust to changes in the environment, and pass these behaviors to offspring.

42.

Tissues are groups of similar cells that work togehter to perform some function. Which of these structures is an example of a tissue?

a.	arm muscle
b.	large intestine
c.	cardiovascular system
d.	mucus that lines the stomach.

43.

In the carbon cycle, which of these processes returns carbon to the air?

a.	respiration
b.	precipitation
c.	evaporation
d.	photosynthesis

44.

Which is a characteristic ONLY found in multicellular organisms?

a.	DNA in cells
b.	differentiation of cells
c.	ability to reproduce
d.	cellular respiration

45.

What three elements are found in all proteins, lipids, carbohydrates, and nucleic acids?

a.	carbon, hydrogen, and oxygen
b.	carbon, hydrogen, and helium
c.	nitrogen, hydrogen, and oxygen
d.	sodium, hydrogen, and oxygen.

46.

What does an organism require to live and grow?

a.	ability to reproduce
b.	absence of genetic mutations
c.	input of energy and raw materials
d.	capacity to perform photosynthesis

47.

Scientists are interested in determining the closest living relative of the giant Galapagos tortise. Which of the following would provide the MOST useful information?

a.	DNA analysis
b.	mating behaviors
c.	analogous structures
d.	geographic distribution

Short Answer

48.

Identify TWO common environmental causes of genetic mutation.

49.

Identify TWO ways in which the fossil record supports the theory of biological evolution.

50.

Using Figure 7 as a reference, explain TWO ways that a dolphin is well adapted for swimming.

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51.

First, what TWO events must occur in order for a single zygote to form both a nerve cell and a muscle cell?

Second, within an organism, explain how the DNA of a nerve cell compares to the DNA of a muscle cell.

52.

The African white lion has a genetic mutation that results in the lack of brown in the coat color of the cat. Natural selection chooses AGAINST the survival of the white lion in the wild. Identify TWO reasons why the white lion is not successful in the wild.

53.

Identify TWO common ways the body maintains homeostasis during exercise.

54.

Crossing over occurs when sections of two homologous chromosomes are exchanged during the process of meiosis. Identify one way that crossing over benefits a species, and then explain how the survival of a species is affected by the results of crossing over.