Download Module B Review

Module B Review
2nd Quarterly Assessment Review
Units 4 & 5
BIO.B.1.1
• Describe the three stages of the cell cycle:
interphase, nuclear division, cytokinesis.
• Describe the events that occur during the cell
cycle: interphase, nuclear division (i.e., mitosis
or meiosis), cytokinesis.
• Compare the processes and outcomes of
mitotic and meiotic nuclear divisions.
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Cells divide at different rates.
• The rate of cell division varies with the need for that
type of cell.
• Some cells are unlikely to divide (in Gap 0/G0 of the cell cycle)
– Example: neurons
Cell size is limited.
• Volume increases faster than surface area.
– Cells need to stay small to allow diffusion and
osmosis to work efficiently.
Mitosis and cytokinesis produce two
genetically identical daughter cells.
• Interphase: prepares the cell
to divide. During interphase,
the DNA is duplicated.
• Prophase: chromosomes
condense, spindle fibers form,
and the nuclear membrane
disappears
Mitosis divides the cell’s nucleus in
four phases.
• Metaphase: chromosomes line up in the
middle of the cell
• Anaphase: sister chromatids are pulled apart
to opposite sides of the cell
Mitosis divides the cell’s nucleus in
four phases.
• Telophase
– Two nuclei form at opposite ends of the cell, the
nuclear membranes reform, and the
chromosomes uncoil back into chromatin
Cytokinesis differs in animal and plant
cells.
• Cytoplasm separates
– Animal cells: membrane pinches
the two new cells apart
– Plant cells: a cell plate (new cell
wall) separates the two new cells
Cell division is uncontrolled in cancer.
• Cancer cells form disorganized clumps called
tumors.
– Benign tumors remain clustered and can be
removed.
– Malignant tumors metastasize, or break away, and
can form more tumors.
5.4 – Asexual Reproduction
• Key Concept:
– Many organisms reproduce by cell division.
Binary fission is similar to mitosis.
• Asexual reproduction is the
creation of offspring from a
single parent.
– Binary fission produces two
daughter cells genetically
identical to the parent cells.
– Binary fission occurs in
prokaryotes.
Some eukaryotes reproduce by mitosis.
• Budding forms a new organism
from a small projection growing
on the surface of the parent.
• Fragmentation is the splitting of
the parent into pieces that each
grow into a new organism.
• Vegetative reproduction forms a
new plant from the modification
of a stem or underground
structure on the parent plant.
Multicellular organisms depend on
interactions among different cell types.
• Tissues are groups of cells that perform a similar
function.
• Organs are groups of tissues that perform a specific
or related function.
• Organ systems are groups of organs that carry out
similar functions.
Specialized cells perform specific
functions.
• Cells develop into their mature forms through
the process of cell differentiation.
• Cells differ because different combinations of
genes are expressed.
• A cell’s location in an embryo helps determine
how it will differentiate.
6.1 – Chromosomes & Meiosis
• Key Concept:
– Gametes have half the number of chromosomes
that body cells have.
You have somatic cells and gametes.
• Somatic Cells:
– Are body cells
– Make up all cells in body except for
egg and sperm cells
– Not passed on to children
• Gametes:
– Are egg or sperm cells
– Passed on to children
Your cells have autosomes and sex
chromosomes.
• Somatic cells have 23 pairs of
chromosomes (46 total)
– (1) Autosomes: pairs 1 – 22; carry
genes not related to the sex of
an
organism
–
(2)
Homologous chromosomes:
pair
ofparent;
chromosomes;
one
from
each
carry
the get
same
genes
but
may
have
a
different
form
of
the gene
(example:
for
brown
eyes
and one one
genegene
for blue
eyes)
– (3) Sex chromosomes: pair 23;
determines the sex of an animal;
control the development of
sexual characteristics
Somatic cells are diploid; gametes are
haploid.
• Diploid (2n)
– Has two copies of each
chromosome (1 from
mother & 1 from father)
• 44 autosomes, 2 sex
chromosomes
– Somatic cells are diploid
– Produced by mitosis
• Haploid (1n)
– Has one copy of each
chromosome
• 22 autosomes, 1
sex chromosome
– Gametes are haploid
– Produced by meiosis
Meiosis I
• Occurs after DNA has been replicated
(copied)
• Divides homologous chromosomes in four
phases.
Meiosis II
• Divides sister chromatids in four phases.
• DNA is not replicated between Meiosis I and
Meiosis II.
Mitosis Vs. Meiosis
Mitosis
• One cell division
• Homologous chromosomes
do not pair up
• Results in diploid cells
• Daughter cells are identical
to parent cell
Meiosis
• Two cell divisions
• Homologous chromosomes
pair up (Metaphase I)
• Results in haploid cells
• Daughter cells are unique
Sexual reproduction creates unique
combinations of genes.
• Fertilization: Random, Increases unique
combinations of genes
• Independent assortment of chromosomes
– Homologous chromosomes pair randomly along
the cell equator
• Crossing over
– Exchange of chromosome segments between
homologous chromosomes
BIO.B.1.2
• Explain how genetic information is inherited.
• Describe how the process of DNA replication
results in the transmission and/or
conservation of genetic information.
• Explain the functional relationships between
DNA, genes, alleles, and chromosomes and
their roles in inheritance.
DNA
• There are 4 types of nitrogenous bases: thymine, adenine, cytosine,
and guanine
• The nitrogen containing bases are the only difference in the four
nucleotides.
Proteins carry out the process of
replication.
• DNA serves only as a template.
• Enzymes and other proteins do the actual
work of replication.
• Process
1. Enzymes unzip the double helix.
2. Free-floating nucleotides form hydrogen bonds
with the template strand.
nucleotide
The DNA molecule
unzips in both directions.
3. DNA polymerase enzymes bond the nucleotides
together to form the double helix.
1. Sugar
Phosphate
Backbone
4. new strand
2. Nitrogen bases
3. DNA polymerase
4. Two new molecules of DNA are formed, each with an original strand and
a newly formed strand.
•
DNA replication is semi-conservative, meaning one original strand and
one new strand.
original strand
Two molecules of DNA
new strand
BIO.B.2.1
• Compare Mendelian and non-Mendelian
patterns of inheritance.
• Describe and/or predict observed patterns of
inheritance (i.e., dominant, recessive, codominance, incomplete dominance, sexlinked, polygenic, and multiple alleles).
Mendel laid the groundwork for
genetics.
• Traits are distinguishing
characteristics that are
inherited. (eye color, hair
color)
• Genetics is the study of
biological inheritance
patterns and variation.
• Gregor Mendel showed
that traits are inherited as
discrete units.
The same gene can have many versions.
• A gene is a piece of DNA that directs a cell to
make a certain protein.
• Each gene has a locus, a
specific position on a pair of
homologous chromosomes.
• An allele is any alternative form of a gene occurring
at a specific locus on a chromosome.
– Each parent donates one
allele for every gene.
– Homozygous describes two
alleles that are the same at a
specific locus. Ex: (RR or rr)
– Heterozygous describes two
alleles that are different at a
specific locus.Ex: (Rr)
•
Alleles can be represented using letters.
– A dominant allele is expressed as a
phenotype when at least one allele is
dominant.
– A recessive allele is expressed as a
phenotype only when two copies are
present.
– Dominant alleles are represented by
uppercase letters; recessive alleles by
lowercase letters.
Punnett squares illustrate genetic
crosses.
• The Punnett square is a grid system for predicting all
possible genotypes resulting from a cross.
– The axes represent
the possible gametes
of each parent.
– The boxes show the
possible genotypes
of the offspring.
•
The Punnett square yields the
ratio of possible genotypes and
phenotypes.
Other Forms of Inheritance
• Incomplete Dominance: 3rd new color
(flowers)
• Co dominance: together (cattle)
• Sex Linked: XX XY (color blindness)
• Pedigrees: circles and squares
• Blood Types AA Ai, BB Bi, AB, ii
(multiple alleles)
Polygenic