Brooks Biological Principles Exam 3
UPDATED ACTUAL Exam Questions and
CORRECT Answers
Mitosis - CORRECT ANSWER✔✔- • the duplication and division of the nucleus
• results in clones with *no* variation or adaptation
• takes place in somatic cells (non-sex cells)
• starts with one cell and creates 2 identical daughter cells
• replicated chromosomes are evenly divided so that each daughter cell receives a complete
set (46 chromosomes)
• *can occur by itself*, but usually involves cytokinesis
• not synonymous with cellular division
• single-celled prokaryotes and single celled eukaryotes reproduce asexually, but eukaryotes
are followed by cytokinesis
Purpose of Mitosis - CORRECT ANSWER✔✔- 1. Growth: to increase the number of cells
2. Tissue repair/replacement
3. Asexual Reproduction
Cell Division - CORRECT ANSWER✔✔- A process by which a parent cell duplicates its
genetic material and then divides into two similar cells
= Cytokinesis
Cytokinesis - CORRECT ANSWER✔✔- • the duplication and divison of the *rest* of the
cell, *excluding* the nucleus
• occurs during telophase
• can happen during mitosis, but generally doesn't have to occur with mitosis
• will either develop into new cell walls (plants) or plasma membranes (animals) for each
daughter cell
Mitosis is not equal to - CORRECT ANSWER✔✔- Cell division/Cytokinesis
,Only duplicates the nucleus, not the entire cell
In the cells of some organisms, mitosis occurs without cytokinesis. This will result in -
CORRECT ANSWER✔✔- cells with more than one nucleus (plasmodium/slime mold)
Ploidy - CORRECT ANSWER✔✔- number of the kinds of chromosomes found in a species
denoted as "n"
What is the ploidy for humans? - CORRECT ANSWER✔✔- diploid, 23 pairs of
chromosomes, 46 chromosomes total
What is the ploidy for bacteria? - CORRECT ANSWER✔✔- diploid, 46 chromosomes
Haploid (n) - CORRECT ANSWER✔✔- 1 set of each kind of chromosome
no homologous chromosomes
*only in gametes*
Diploid (2n) - CORRECT ANSWER✔✔- 2 sets of each kind of chromosome, one set
inherited from each parent
contains a pair of homologous chromosomes
*in all other body cells*
You should do a ploidy count when - CORRECT ANSWER✔✔- the mitotic or meiotic
stages have been completed, and new nuclear membranes separated into the sets of DNA
Most cells in the body are - CORRECT ANSWER✔✔- diploid
Mitosis - CORRECT ANSWER✔✔- takes any ploidy condition and makes exact copies of
that condition
,Meiosis - CORRECT ANSWER✔✔- is not versatile (must have a diploid cell) to yield a
haploid cell
Germinal Cells - CORRECT ANSWER✔✔- Cells involved directly in the process of
reproduction, like testes and ovaries
Somatic Cells - CORRECT ANSWER✔✔- •body cells that are not specialized for
reproduction
Ex: muscle and skin
•can't undergo *meiosis*
•human cells have *46 chromosomes* in their somatic cells (contain two sets of
chromosomes known as *homologous pairs* they are not identical, but they have similar,
specialized characteristics)
Homologous Chromosome Pairs - CORRECT ANSWER✔✔- Refers to *pairs* of the
*same* kind of chromosome
organized by having the same size that contain genes for the same traits
They are diploid
23 pairs of homologous chromosomes in humans
Locus - CORRECT ANSWER✔✔- Location of the genes in homologues
How many different ways can homologous chromosomes line up? - CORRECT
ANSWER✔✔- over 8 million ways
Karyotyping - CORRECT ANSWER✔✔- visual representation of chromosomes by length,
size, & centromeres in the same position pairing up
chromosome 23 determines sex
chromosome 21 most likely to duplicate
useful because you can count the number of chromosomes present
Which chromosome has the tendency to have an extra? - CORRECT ANSWER✔✔- 21, less
likely to separate due to nondisjunction
, Down Syndrome - CORRECT ANSWER✔✔- Problem with Chromosome 21
Does not separate like it should (Trisomy 21)
Autosomal chromosomes - CORRECT ANSWER✔✔- Chromosomes 1 to 22 in humans
Cell Cycle - CORRECT ANSWER✔✔- •Before mitosis begins, the cell must first grow and
duplicate chromosomes during *interphase;* cells go through four stages during cell
reproduction
•Once this cycle is complete the cell will either undergo mitosis or meiosis
Interphase - CORRECT ANSWER✔✔- known as "resting phase"
•*majority* of the cell's life is spent in this phase
•*occurs between mitotic events, not the first stage of mitosis*
•it is a stage of the cell cycle where the cell grows and genetic material is copied
•main metabolic events occur: photosynthesis & cellular respiration
•*DNA is fully functional during interphase*
3 Stages of Interphase - CORRECT ANSWER✔✔- G1 - Gap 1
S - DNA Synthesis
G2 - Gap 2
G1 Phase - CORRECT ANSWER✔✔- • Active Growth and Metabolism
• This is where you have the *most* cellular activity
• The cell grows larger
• Unduplicated DNA (chromatin); cellular content, excluding the chromosomes, are
duplicated
• Final destination for adult cells:neurons and muscles (don't divide, so they don't go thru S
phase, just stay in G1, so called G0)
UPDATED ACTUAL Exam Questions and
CORRECT Answers
Mitosis - CORRECT ANSWER✔✔- • the duplication and division of the nucleus
• results in clones with *no* variation or adaptation
• takes place in somatic cells (non-sex cells)
• starts with one cell and creates 2 identical daughter cells
• replicated chromosomes are evenly divided so that each daughter cell receives a complete
set (46 chromosomes)
• *can occur by itself*, but usually involves cytokinesis
• not synonymous with cellular division
• single-celled prokaryotes and single celled eukaryotes reproduce asexually, but eukaryotes
are followed by cytokinesis
Purpose of Mitosis - CORRECT ANSWER✔✔- 1. Growth: to increase the number of cells
2. Tissue repair/replacement
3. Asexual Reproduction
Cell Division - CORRECT ANSWER✔✔- A process by which a parent cell duplicates its
genetic material and then divides into two similar cells
= Cytokinesis
Cytokinesis - CORRECT ANSWER✔✔- • the duplication and divison of the *rest* of the
cell, *excluding* the nucleus
• occurs during telophase
• can happen during mitosis, but generally doesn't have to occur with mitosis
• will either develop into new cell walls (plants) or plasma membranes (animals) for each
daughter cell
Mitosis is not equal to - CORRECT ANSWER✔✔- Cell division/Cytokinesis
,Only duplicates the nucleus, not the entire cell
In the cells of some organisms, mitosis occurs without cytokinesis. This will result in -
CORRECT ANSWER✔✔- cells with more than one nucleus (plasmodium/slime mold)
Ploidy - CORRECT ANSWER✔✔- number of the kinds of chromosomes found in a species
denoted as "n"
What is the ploidy for humans? - CORRECT ANSWER✔✔- diploid, 23 pairs of
chromosomes, 46 chromosomes total
What is the ploidy for bacteria? - CORRECT ANSWER✔✔- diploid, 46 chromosomes
Haploid (n) - CORRECT ANSWER✔✔- 1 set of each kind of chromosome
no homologous chromosomes
*only in gametes*
Diploid (2n) - CORRECT ANSWER✔✔- 2 sets of each kind of chromosome, one set
inherited from each parent
contains a pair of homologous chromosomes
*in all other body cells*
You should do a ploidy count when - CORRECT ANSWER✔✔- the mitotic or meiotic
stages have been completed, and new nuclear membranes separated into the sets of DNA
Most cells in the body are - CORRECT ANSWER✔✔- diploid
Mitosis - CORRECT ANSWER✔✔- takes any ploidy condition and makes exact copies of
that condition
,Meiosis - CORRECT ANSWER✔✔- is not versatile (must have a diploid cell) to yield a
haploid cell
Germinal Cells - CORRECT ANSWER✔✔- Cells involved directly in the process of
reproduction, like testes and ovaries
Somatic Cells - CORRECT ANSWER✔✔- •body cells that are not specialized for
reproduction
Ex: muscle and skin
•can't undergo *meiosis*
•human cells have *46 chromosomes* in their somatic cells (contain two sets of
chromosomes known as *homologous pairs* they are not identical, but they have similar,
specialized characteristics)
Homologous Chromosome Pairs - CORRECT ANSWER✔✔- Refers to *pairs* of the
*same* kind of chromosome
organized by having the same size that contain genes for the same traits
They are diploid
23 pairs of homologous chromosomes in humans
Locus - CORRECT ANSWER✔✔- Location of the genes in homologues
How many different ways can homologous chromosomes line up? - CORRECT
ANSWER✔✔- over 8 million ways
Karyotyping - CORRECT ANSWER✔✔- visual representation of chromosomes by length,
size, & centromeres in the same position pairing up
chromosome 23 determines sex
chromosome 21 most likely to duplicate
useful because you can count the number of chromosomes present
Which chromosome has the tendency to have an extra? - CORRECT ANSWER✔✔- 21, less
likely to separate due to nondisjunction
, Down Syndrome - CORRECT ANSWER✔✔- Problem with Chromosome 21
Does not separate like it should (Trisomy 21)
Autosomal chromosomes - CORRECT ANSWER✔✔- Chromosomes 1 to 22 in humans
Cell Cycle - CORRECT ANSWER✔✔- •Before mitosis begins, the cell must first grow and
duplicate chromosomes during *interphase;* cells go through four stages during cell
reproduction
•Once this cycle is complete the cell will either undergo mitosis or meiosis
Interphase - CORRECT ANSWER✔✔- known as "resting phase"
•*majority* of the cell's life is spent in this phase
•*occurs between mitotic events, not the first stage of mitosis*
•it is a stage of the cell cycle where the cell grows and genetic material is copied
•main metabolic events occur: photosynthesis & cellular respiration
•*DNA is fully functional during interphase*
3 Stages of Interphase - CORRECT ANSWER✔✔- G1 - Gap 1
S - DNA Synthesis
G2 - Gap 2
G1 Phase - CORRECT ANSWER✔✔- • Active Growth and Metabolism
• This is where you have the *most* cellular activity
• The cell grows larger
• Unduplicated DNA (chromatin); cellular content, excluding the chromosomes, are
duplicated
• Final destination for adult cells:neurons and muscles (don't divide, so they don't go thru S
phase, just stay in G1, so called G0)
