BIOLOGY PROCTORED EXAM PENN FOSTER 2023-2024
ACTUAL EXAM/PENN FOSTER BIOLOGY PROCTORED
EXAM LATEST 200 QUESTIONS AND CORRECT
ANSWERS(VERIFIED ANSWERS)|AGRADE
Explain the process of diffusion: – ANSWER- Molecules move from an area of
higher concentration to an area of lower concentration until the concentration of
molecules is the same at both sites
Explain the process of osmosis: – ANSWER- Water moves from areas of low
solute concentration to areas of high solute concentration
Describe a basic enzymatic reaction: – ANSWER- S+E= P+E
E represents the enzyme catalyzing the reaction
S is the substance being changed
P is the product of the reaction
What is an enzyme? – ANSWER- Catalysts that increase the speed of a chemical
reaction without undergoing any permanent chemical change
What is the process of photosynthesis? – ANSWER- -The process in which the
Sun’s energy is converted into chemical energy (occurs in chloroplasts).
-Carbon dioxide and water are added
-Sugar and oxygen are produced
What is cellular respiration? – ANSWER- Cellular respiration is the process that
releases energy from food in the presence of oxygen.
What is the cellular respiration equation? – ANSWER- 6O2 + C6H12O6 -> 6CO2
- 6H2O + Energy
What is glycolysis? – ANSWER- “splitting sugars.” yields two molecules of ATP.
What is Krebs cycle? – ANSWER- This term refers to a series of chemical
reactions that involve the complete oxidation of acetyl CoA and produce 2 mol of
ATP (energy) along with hydrogen and carbon, which combine with oxygen to
form (H2O) and (CO2).
What is the electron transport chain? – ANSWER- Is a sequence of electron carrier
molecules that shuttle electrons,
down a series of reactions that release energy; used to make ATP.
What is cellular reproduction? – ANSWER- Process by which cells divide to form
new cells
Growth phase- cell duplicates its contents and DNA
Cell Division- the cytoplasm and DNA of a parent cell are distribute to 2 daughter
cells
How many chromosomes do humans have? – ANSWER- 46 (23 pairs)
What is nondisjunction and when does it occur? – ANSWER- Nondisjunction
occurs when chromosomes do not separate properly during cell division. This can
form a gamete with an extra chromosome or one missing part or all of a
chromosome (aka monosomy or trisomy). OCCURS DURING ANAPHASE 1 & 2
What is the law of dominance? – ANSWER- Mendel’s 2nd law of inheritance – one
gene usually expresses itself over the other (one gene is dominant over the other)
What is the law of segregation? – ANSWER- during the production of gametes the
two copies of each hereditary factor segregate so that offspring acquire one factor
from each parent
What is the law of independent assortment? – ANSWER- Genes for different traits
are inherited independently of each other
What is DNA biotechnology and what are some issues? – ANSWER- Use of
natural biological systems to create a product or achieve some other end desired by
humans
Issues:
-People feel it goes against the laws of nature
-People worry about the safety of it
How can lack of genetic control lead to cancer? – ANSWER- When someone has
inherited an abnormal copy of a gene, their cells already start out with one
mutation. This makes it easier for enough mutations to build up for a cell to
become cancer
G1 (Growth 1) – ANSWER- Cell volume doubles and organelles replicate
S phase (synthesis) – ANSWER- DNA is replicated
G2 phase – ANSWER- cell produces proteins necessary for mitosis and then
prepares to divide
What are the stages of mitosis? – ANSWER- prophase= chromosomes become
visible as paired chromatids and the nuclear enveloped disappears
metaphase= the chromosomes are aligned at the spindle equator midway between
the spindle poles
anaphase= sister chromatids separate and become daughter chromosomes- each
pole receives a set of daughter chromosomes
telophase= spindle disappears as new nuclear envelopes form around the daughter
chromosomes- each nucleus contains the same number and kinds of chromosomes
the original parent nucleus
Describe the purpose of the cell cycle control system – ANSWER- Series of
checkpoints to make sure that everything is proceeding properly. Checkpoints
delay development from one phase off the cycle to the next until everything that
should happen in a particular phase has happened
Explain the phases of the cell cycle control system: – ANSWER- G1= cell can
enter GO or under apoptosis if DNA is damaged beyond repair. If the cell cycle
passes his checkpoint, the cell is committed to complete the cycle
G2= the cell checks to make sure DNA has been replicated properly
M Checkpoint= cell makes sure the chromosomes are properly aligned and ready
to be partitioned to the daughter cells
What is apoptosis? – ANSWER- Programmed chemical process that causes a cell
to self-destruct
Serves the purpose of keeping the number of cells in the body roughly constant and
removing cells with damaged DNA
Explain the basics of mitosis – ANSWER- Type of cell division in which one
cell(the mother) divides to produce 2 new cells(the daughters) that are genetically
identical to itself
Somatic cells aids in the growth and development of an organism as well as in the
replacement of old and injured cells
- results in 2 daughter cells that are genetically identical
Explain the basics of meiosis – ANSWER- Type of cell division in which the
number of chromosome is reduced in half from the diploid number (2n) to a
haploid number (n). The result is 4 gametes: eggs in females and sperm in males
Reproductive cells produces gametes for sexual reproduction - The gametes contain half the number of chromosomes as the parent cell
What are the stages of meiosis I? – ANSWER- Interphase: DNA in the cell is
copied resulting in 2 identical full sets of chromosomes
Prophase 1: the copied chromosomes condense into x shaped structure- each
chromosome is composed of 2 sister chromatids
Metaphase 1: chromosome pairs line up next to each other along the center of the
cell
Anaphase 1: pair of chromosomes are pulled apart, pull one chromosome to each
pole
Telophase 1: chromosomes complete their move to opposite poles of the cell- 2
nuclei form
What are the stages of meiosis II? – ANSWER- Prophase II: 2 daughter cells, each
with 23 chromosomes - membrane around the nucleus in each daughter cell dissolves away releasing
chromosomes
Metaphase II: 2 daughter cells in chromosomes line up end-to-end along the
equator of the cell
Anaphase II: Sister chromatids are then pulled to opposite poles due to the action
of the meiotic spindle- separated chromatids are now individual chromosomes
Telophase II: Chromosomes complete their move to the opposite poles of the cell - Membrane forms around each set of chromosomes to create 2 new cell nuclei
What is the structure and function of DNA? – ANSWER- Long chain of repeating
units called nucleotide that consist of 2 strands that spiral around each other in a
structure called double helix