BIOLOGY PROCTORED EXAM PENN FOSTER
UPDATED QUESTIONS AND ANSWERS
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? - CORRECT ANSWER -
46 (23 pairs)
What is nondisjunction and when does it occur? - CORRECT
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? - CORRECT 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? - CORRECT 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? - CORRECT ANSWER -
Genes for different traits are inherited independently of each other
,What is DNA biotechnology and what are some issues? - CORRECT
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? - CORRECT
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) - CORRECT ANSWER -Cell volume doubles and
organelles replicate
S phase (synthesis) - CORRECT ANSWER -DNA is replicated
G2 phase - CORRECT ANSWER -cell produces proteins necessary
for mitosis and then prepares to divide
What are the stages of mitosis? - CORRECT 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 - CORRECT
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: - CORRECT
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? - CORRECT 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 - CORRECT 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 - CORRECT 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? - CORRECT 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? - CORRECT 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
UPDATED QUESTIONS AND ANSWERS
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? - CORRECT ANSWER -
46 (23 pairs)
What is nondisjunction and when does it occur? - CORRECT
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? - CORRECT 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? - CORRECT 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? - CORRECT ANSWER -
Genes for different traits are inherited independently of each other
,What is DNA biotechnology and what are some issues? - CORRECT
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? - CORRECT
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) - CORRECT ANSWER -Cell volume doubles and
organelles replicate
S phase (synthesis) - CORRECT ANSWER -DNA is replicated
G2 phase - CORRECT ANSWER -cell produces proteins necessary
for mitosis and then prepares to divide
What are the stages of mitosis? - CORRECT 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 - CORRECT
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: - CORRECT
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? - CORRECT 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 - CORRECT 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 - CORRECT 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? - CORRECT 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? - CORRECT 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
