Biology Practice Midterm
Directions: This practice midterm is designed to test your knowledge of Biology (as is
outlined by the CA State Standards). While the real test will be longer and have different
questions the knowledge covered will be the same. If you do well on this test you can
expect to do well on the final. Good luck! Check the website pvbiology.wordpress.com
for the answers after 6pm.
Standard 1a: Cell Membranes
1. Some molecules move across the cell membrane, while others cannot cross the
membrane. This is because the ________.
a. cell is alive
b. molecules are polar
c. membrane is semipermeable (selectively permeable)
d. cytoplasm is salty
2. The main role of the cell membrane is to _______.
a. regulate the cell’s interactions with the environment
b. release any type of molecule out of the cell
c. arrange the cell’s organelles in the cytoplasm
d. prevent water from leaking into the cell
3. What types of molecules are embedded in the cell membrane that allow larger
molecules to pass through the membrane by active transport?
a. phospholipids
b. proteins
c. ATP
d. carbohydrates
4. Osmosis is the movement of water across a cell membrane. Osmosis is a type of
______.
a. diffusion
b. lipid
c. active transport
d. fluid mosaic model
Standard 1b: Enzymes
5. The function of an enzyme is to ________ the amount of energy needed to start a
chemical reaction.
a. increase
b. reduce
c. equal
d. have no affect on
6. After the enzyme amylase breaks down a starch molecule, it can _____.
a. not be reused
b. change its shape to adapt to a different reactant
c. alter the equilibrium conditions
d. break down more starch molecules
7. Enzymes depend on their structure to function properly. Which of the following does
NOT alter an enzymes structure?
a. temperature
b. pH
c. concentration of reactants
d. ionic conditions
8. In the graph, which reaction is catalyzed by an enzyme?
a. A
b. B
c. both A and B
d. neither A nor B
Standard 1c: Cell Types
9. The cell on the right has free floating DNA (no nucleus). What type of cell is this
most likely to be?
a. prokaryotic
b. eukaryotic
c. viral
d. animal
10. Eukaryotes and prokaryotes are similar in that they both have a ____.
a. nucleus
b. mitochondria
c. golgi apparatus
d. cell membrane
11. If you are looking at cells under a powerful microscope, what is the best way for you
to tell the difference between prokaryotic cells and eukaryotic cells?
a. Prokaryotic cells will always have cell walls, but eukaryotic cells will not.
b. Prokaryotic cells will never have a cell membrane, but eukaryotic cells will.
c. Prokaryotic cells will have either RNA or DNA, but eukaryotic cells will have
both.
d. Prokaryotic cells will not have membrane-bound organelles such as a nucleus,
but eukaryotic cells will.
12. Which of these is a prokaryote?
a. HIV
b. liver cell
c. E. coli bacteria
d. onion cell
Standard 1e: Protein Secretion
13. If a cells endoplasmic reticulum is not functioning correctly, what may happen?
a. The cell cannot complete mitosis.
b. There is a disruption in DNA replication.
c. The cell has trouble creating finished proteins.
d. The cell fails to absorb nutrients.
14. There are two types of endoplasmic reticulum – rough and smooth. What is the main
difference between the two types?
a. the presence of ribosomes
b. the presence of a membrane
c. the presence of a golgi apparatus
d. the presence of mitochondria
15. Insulin is a protein that stimulates cells to remove glucose from the blood. Which cell
structure is most directly involved in releasing insulin from the cells in the pancreas?
a. mitochondria
b. nucleus
c. cytoskeleton
d. golgi apparatus
16. Sometimes the golgi apparatus is described as the cells “post office”. This is because
the golgi apparatus _________.
a. holds molecules for organelles to pick them up
b. facilitates diffusion
c. sorts and packages proteins
d. stores carbohydrates in compartments
Standard 1f: Photosynthesis
17. What products are formed by photosynthesis?
a. carbon dioxide and energy
b. water and oxygen
c. chlorophyll and carbon dioxide
d. sugar and oxygen
18. Plants are called producers because they have chloroplasts that ____.
a. release energy from sugars
b. produce heat needed to keep the plant warm
c. use oxygen to make water
d. use energy from sunlight to produce the plant’s own food
19. Which of the following is true about how plants interact with their environment
during photosynthesis?
a. They release water into the atmosphere.
b. They reflect all of the energy in sunlight into the atmosphere.
c. They remove carbon dioxide from the atmosphere to make glucose.
d. They take oxygen out of the atmosphere.
20. Which of the following best describes the function of photosynthesis?
a. To convert energy from sunlight into stored chemical energy of sugar.
b. To release energy from sugar into the atmosphere.
c. To produce water for plants to use in photosynthesis.
d. To dispose of carbon dioxide that builds up by digesting food.
Standard 1g: Cellular Respiration
21. What is the missing product in the equation below?
sugar + oxygen  carbon dioxide + water + ______
a.
b.
c.
d.
mitochondria
ATP
sugar
sunlight
22. Mitochondria are often called the cell’s powerhouses because mitochondria _______.
a. release energy from sugars
b. pump oxygen around the cell
c. distribute electricity
d. direct the movement of the cell
23. During cellular respiration, a series of chemical reactions produces which of the
following molecules as a waste product?
a. proteins
b. carbon dioxide
c. ATP
d. oxygen
24. Which of the following does the heart need the most in order to get the energy it
needs to pump blood throughout the body?
a. lysosomes
b. mitochondria
c. DNA
d. endoplasmic reticulum
Standard 1h: Macromolecules
25. DNA is the genetic material that codes for a sequence of amino acids. Many amino
acids make up a protein. Which are the monomers of a protein?
a. cellulose
b. nucleotides
c. amino acids
d. DNA
26. Fats and oils are examples of _______.
a. lipids
b. proteins
c. nucleic acids
d. carbohydrates
27. What are the monomers that carbohydrates are composed of?
a. proteins
b. monosaccharides
c. macromolecules
d. amino acids
28. DNA and RNA are two types of ______.
a. proteins
b. nucleic acids
c. lipids
d. carbohydrates
Standard 2a: Meiosis
29. Meiosis produces _______.
a. chromatids
b. gametes
c. zygotes
d. genes
30. Which of the following best describes the role meiosis plays in sexual reproduction?
a. Meiosis allows chromosomes to condense.
b. Meiosis produces cells with half the number of chromosomes and various
combinations of chromosomes.
c. Meiosis gets chromosomes to pair up along the cell equator.
d. Meiosis forms new somatic cells.
31. A cell has four chromosomes before meiosis begins. When the entire process of
meiosis is completed, how many chromosomes will each of the new cells contain?
a. 1
b. 2
c. 3
d. 4
32. A hypothetical organism has 18 chromosomes in its body cells. Which of the
following best describes the organism?
a. The organism will have offspring with 36 chromosomes.
b. The organism resulted when 9 chromosomes from each parent combined.
c. The organism’s chromosomes were all originally found in the same gamete.
d. The organism has half as much genetic information as the parents’ gametes.
Standard 2b: Gametes
33. In order for a mutation to be passed on to the offspring of a plant, which cells must
contain the mutated DNA?
a. Cells that produce the gametes.
b. Cells that are found in the stem.
c. Cells that can be added to a new plant.
d. Cells that form the leaves.
34. In which organ can you find cells that undergo meiosis?
a. kidney
b. brain
c. ovary
d. heart
35. Which of the following is true of cells that can be found in the finger?
a. They will never undergo meiosis
b. They will undergo meiosis at different times of the organism’s life.
c. They will undergo meiosis only when they are stimulated
d. They will undergo meiosis after they have duplicated their DNA
36. Meiosis divides the chromosome number in ____.
a. 1/3
b. 1/4
c. 1/2
d. 1/8
Standard 2c: Chromosome Segregation
37. Which of the following best describes the result of meiosis?
a. Chromosomes are replicated.
b. Chromosomes are larger in some cells.
c. Chromosomes are very organized.
d. Chromosomes are randomly separated.
38. Suppose a cat is heterozygous for dark fur. When the cat reproduces some of the
offspring may have the gene for dark fur, while others do not. Which best explains
this?
a. Some genetic material breaks down during meiosis.
b. Most genetic material is not represented in the gametes.
c. All genetic material is divided randomly during meiosis.
d. Little genetic material actually codes for the dark fur color.
39. During meiosis, the random segregation of homologous chromosomes allows cells to
produce large amounts of _______.
a. genetic variation
b. sister chromatids
c. random chance
d. live offspring
40. In the diagram the chromosomes that came from the mother are dark-colored and the
chromosomes that came from the father are light colored. The gametes produced by
meiosis from this cell will contain ______.
a. only chromosomes from the mother
b. only chromosomes from the father
c. an equal mix of chromosomes from the mother and the father
d. a random mix of chromosomes from the mother and father
Standard 2d: Fertilization
41. A cell has 6 chromosomes after fertilization. It has ______.
a. six chromosomes from its mother
b. six chromosomes from its father
c. three chromosomes from its mother and three from its father
d. four chromosomes from its mother and two from its father
42. Which of the following best explains how fertilization contributes to genetic
diversity?
a. It allows parents’ chromosomes to combine.
b. It provides parents’ chromosomes the time for crossing over.
c. It produces gametes with different combinations of chromosomes.
d. It stimulates zygotes to replicate the best chromosomes.
43. How do both fertilization and meiosis allow for genetic variation?
a. They eliminate bad genes.
b. They segregate and form different combinations of genes.
c. They transfer the parents’ genotypes to the offspring.
d. They produce similar phenotypes in all of their cells.
44. Suppose two parent plants were crossed. One has two dominant alleles (RR) and the
second has two recessive alleles (rr). If the two were to mate, they would produce
offspring with
a. Half of their alleles from each parent
b. Both alleles from their mother
c. Both alleles from their father
d. Uneven distribution of alleles from both parents
Standard 2e: DNA
45. If an organism has 8 chromosomes, when two of these organisms mate how many
chromosomes will the mother contribute to the offspring?
a. 1
b. 2
c. 3
d. 4
46. A diploid cell in a human has ______ chromosomes.
a. 23
b. 44
c. 46
d. 48
47. In humans, males have XY sex chromosomes. What can the male contribute his
child?
a. both X and Y
b. X or Y
c. X only
d. Y only
48. Cows have 60 chromosomes in their somatic cells. How many chromosomes would
be found in a haploid cell.
a. 20
b. 25
c. 30
d. 60
Standard 2f: Sex Determination
49. If each sperm in the diagram fertilizes a different egg, what will be the sex of the
resulting offspring?
a. two males
b. two females
c. one male, one female
d. not enough information is given to
be able to tell
50. In humans, males determine the gender of their offspring. Which of the following
statements best explains why this is?
a. females can only contribute X chromosomes, while males may contribute an
X or Y
b. females do not prefer male or female offspring
c. females lose their Y chromosome during meiosis
d. male hormones determines their offspring’s gender
51. The diagram on the right shows a cross between two people. How
many of their offspring will likely be female?
a. None
b. ¼
c. ½
d. all
52. Occasionally people might have three sex chromosomes, such as XXY. However,
offspring NEVER have XYY. Which statement best explains this?
a. XYY offspring die before they are born.
b. The Y chromosome is too weak to occur twice in one offspring.
c. The total of the parent’s sex chromosomes adds up to three X chromosomes,
but only one Y chromosome.
d. Parents with XYY are infertile.
Standard 2g: Predicting Allele Combinations
53. In moths, the gene for dark wings (D) is dominant over the gene for light wings (d).
If a homozygous dark moth (DD) is crossed with a heterozygous dark moth (Dd),
which combination of alleles will be most common in the offspring?
a. DD
b. Dd
c. dd
d. DD and Dd are equally common
54. The letters inside the grid boxes of a Punnett square represent the ________.
a. genotypes of the parents
b. phenotypes of the parents
c. genotypes of the offspring
d. phenotypes of the offspring
55. In the Punnett square below, which combination of alleles will be found in the box
with the question mark?
T
t
T
TT Tt
t
?
tt
a. TT
b. Tt
c. tt
d. TtTt
56. The gene for brown eyes (B) is dominant over the gene for blue eyes (b). If a man
that is heterozygous for brown eyes has children with a woman that has blue eyes,
what is the probability that their children will have blue eyes?
a. 0%
b. 25%
c. 50%
d. 75%
Standard 3a: Predicting Phenotypes
57. Suppose you cross a pea plant with purple flowers with a pea plant that has white
flowers. All the offspring turn out purple. What can you conclude?
a. The offspring have only dominant alleles in their genotype.
b. The offspring have only recessive alleles in their genotype.
c. The offspring have a dominant and a recessive allele in their genotype, but
only the dominant allele shows up in the phenotype.
d. The offspring have a mixture of their parent’s traits.
58. Huntington’s disease is a genetic disease that causes the brain cells to die around the
age of 40. Suppose it is caused by a dominant allele. If and affected man (DD) and
an unaffected woman (dd) have children, what percentage of their children are at risk
for developing the disease?
a. 0%
b. 50%
c. 75%
d. 100%
59. Which of the following is true about sex-linked genes in humans?
a. These genes are usually located on the X chromosomes.
b. Males are less likely to be affected by sex-linked genetic disorders.
c. These genes are always fatal.
d. Females only have one copy of a sex-linked gene.
60. In fruit flies the gene for eye color is a sex-linked gene. Red eyes (R) is dominant
over white eyes (r). What is the phenotype of a fruit fly with the genotype XRXr?
a. red eyes
b. white eyes
c. red and white spotted eyes
d. pink eyes
Standard 3b: Mendel’s Laws
61. Individuals have two genes for each trait. Each parent contributes only one gene for
each trait to the offspring. Which term best describes these statements?
a. law of dominance
b. law of segregation
c. law of independent assortment
d. genetic linkage
62. Suppose two parents have two children. One child has brown hair and brown eyes.
The second child has brown hair and blue eyes. Which statement best explains how
these offspring can have the same hair type but different eye color?
a. The genes these two children have come from different parents.
b. The genes that code for hair color and eye color are located on the sex
chromosomes.
c. The genes that code for hair color and eye color on the same autosome.
d. The genes that code for hair color and eye color are on different autosomes
and will therefore be passed on independently.
63. If an individual has the genotype Aa, which alleles will be found in the gametes?
a. All will have the A allele.
b. All will have the a allele.
c. Half will have the A allele , half will have the a allele.
d. All will have the A and a alleles.
64. Which of the following best describes Mendel’s conclusion about how multiple traits
are passed on the offspring?
a. Traits are always passed in pairs.
b. Traits get passed equally to offspring.
c. Traits are passed independently of one another.
d. Traits do not get passed to offspring.