1.
A few bacteria are placed in a nutrient solution. After several hours, thousands of bacteria are present. Which life activities are primarily responsible for this?
A. 
B. 
Digestion and reproduction
C. 
Circulation and respiration
D. 
Excretion and coordination
2.
Two slides A & B contain Elodea leaves (an aquatic water plant) Slide A is mounted in tap water that is 1% salt and 99% water. Slide B is mounted in a salt solution that is 6% salt and 94 % water. Elodea cells usually contain 1% salt. Ten minutes after the slides were prepared, a microscopic examination of cells in leaves A and B would most likely show evidence that
A. 
Water had moved out of the cells of leaf B
B. 
Salt had moved out of the cells of leaf B
C. 
Water had moved into the cells of leaf A
D. 
Salt had moved into the cells of leaf A
3.
One reason a fish that lives in the ocean may have trouble living in a freshwater lake is that
A. 
There are more carnivores in freshwater habitats
B. 
Salt water holds more dissolved nitrogen than freshwater
C. 
More photosynthesis occurs in fresh water than in salt water
D. 
Water concentration in the fish is affected by salt levels in its environment
4.
Refer to the following diagram of a beaker with a membrane dividing it into two halves containing two kinds of molecules. Which process explains the change in the positions of molecules after 5 hours?
A. 
B. 
C. 
D. 
5.
The diagram shows how an animal is organized. Which label is needed to complete the diagram?
A. 
B. 
C. 
D. 
6.
In the diagram of the amoeba ( a single-celled organism) the arrows show the direction of movement of various substances.Which of the cell's life activities are represented by the arrows?
A. 
Digestions, reproduction, and respiration
B. 
Excretion, transport, and respiration
C. 
Immunity, digestion, and movement
D. 
Digestion, coordination, and reproduction
7.
Which word equation represents the process of photosynthesis?
A. 
Starch -> many glucose molecules
B. 
Glucose + oxygen -> carbon dioxide + water + energy
C. 
Carbon dioxide + water -> glucose + oxygen
D. 
8.
Which process removes carbon dioxide from the atmosphere rather than adding it?
A. 
B. 
C. 
D. 
9.
Which process in plants produces carbon dioxide?
A. 
B. 
C. 
D. 
10.
Which statement best describes the enzyme represented in the following graphs?
A. 
This enzyme works best at a temperature of 37 degrees C and a pH of 8.
B. 
This enzyme works best at a temperature of 55 degrees C and a pH of 12.
C. 
Temperature and pH have no effect on the action of this enzyme.
D. 
This enzyme works best at a temperature near freezing and a pH above 4 .
11.
What is the technique of genetic engineering in which DNA is transferred from the cells of one organism to the cels of another?
A. 
B. 
C. 
D. 
12.
A portion of DNA has the following sequence: A-T-C-G-T-A. Which DNA strand could corectly pair with the one given?
A. 
B. 
C. 
D. 
13.
Compared to the number of chromosomes in a normal human body cell, the number of chromosomes in a normal sperm cell is
A. 
B. 
C. 
D. 
14.
Children born to the same parents are usually very different from each other. These differences result primarily from the process of
A. 
B. 
C. 
D. 
15.
Human growth and sexual development are controlled by
A. 
B. 
C. 
D. 
16.
Which is arranged in the correct sequence?
A. 
Fertilization -> embryo development -> meiosis -> birth
B. 
Embryo development -> meiosis -> fertilization -> birth
C. 
Meiosis -> fertilization -> embryo development -> birth
D. 
Fertilization -> meiosis -> embryo development -> birth
17.
The technique illustrated in the diagram is known as
A. 
B. 
C. 
D. 
18.
During which part of this cycle does the breakdown of the thickened uterine lining occur?
A. 
B. 
C. 
D. 
19.
On or about which day is the egg released from the ovary?
A. 
B. 
C. 
D. 
20.
The hormone FSH stimulates the development of a follicle in the ovary of a human female. As the follicle develops, it secretes estrogen. A high level of estrogen decreases the secretion of FSH. This mechanism is an example of
A. 
B. 
C. 
D. 
21.
Which hormones are secreted by the ovaries?
A. 
Progesterone and estrogen
B. 
C. 
D. 
22.
What is the average length of this reproductive cycle?
A. 
B. 
C. 
D. 
23.
Which mutation could be passed onto future generations?
A. 
B. 
Cancer caused by excessive exposure to the sun
C. 
A chromosomal alteration during gamete formation
D. 
A random breakage of a chromosome in a leaf cell of a maple tree
24.
The DNA sequences found in two different species are 95% the same. This suggests that these species
A. 
Are evolving into the same species
B. 
Contain identical proteins
C. 
May have similar evolutionary histories
D. 
Have the same number of mutations
25.
DDT is an insecticide that accumulates in the fatty tissues of animals and is transferred through food chains. Its concentration increases at each link of a food chain. Which organism in a food chain is more likely to accumulate the highest concentration of DDT?
A. 
B. 
C. 
D.