Transcript Strand V Review

CAPT REVIEW
STRAND V
Mrs. Scicchitano
MARCH 2013
OBJECTIVE:
Explain how meiosis contributes to
the genetic variability of
organisms.

MITOSIS: The process of cell
division that occurs in
somatic cells. The new cells
are genetically identical to
the original cell.

SOMATIC CELLS: body cells
(ex. skin cells, stomach
cells, muscle cells).

MEIOSIS: The process of cell division that creates
gamete cells. These cells are genetically different to the
parent cells.

GAMETE CELL: are reproductive cells produced in
sex organs. Sperm are produced in the testes of
males. Eggs are produced in the ovaries of females.
ZYGOTE: an egg that has been
fertilized by a sperm cell


OFFSPRING: child
•During meiosis the cells
goes through division
TWICE!
•At the end of meiosis
there are 4 daughter cells
that are haploid.
•The daughter cells have
HALF the normal number
of chromosomes.
Symbolically this is known
as n.
Diploid Cell (2n):
number of
chromosomes
found in somatic
cells

Haploid (n):
number of
chromosomes
found in gamete cells

Diploid # for humans: 46
 Haploid # for humans: 23

Why do siblings look different?
GENETIC VARIABILITY:
Meiosis creates unique sperm
and eggs that have individual
characteristics.
There are two ways genetic
variability occurs
1. Fertilization - when a random sperm and random
egg combine to form a zygote.
2. Crossing Over – when two pairs of chromosomes link
together and segments of DNA are exchanged during
meiosis.
OBJECTIVE:
Use the Punnett Square technique to
predict the distribution of traits in
monohybrid and dihybrid crossings.
DOMINANT allele
An allele (gene) that can
“mask over” a recessive
allele.
It is represented by a
CAPTIAL letter.
RECESSIVE allele
An allele (gene) that can
only be expressed if a
dominant allele is
absent.
It is represented by a
LOWER CASE letter.
Ex. “B”
Ex. “b”
HOMOZYGOUS
(purebred)
HETEROZYGOUS
(hybrid)
When a pair of alleles When a pair of alleles
for a gene are
for a gene are
DIFFERENT.
IDENTICAL or the
SAME.
Ex. BB or bb
Ex. Bb
GENOTYPE
PHENOTYPE
The description of the
gene pair.
The observable trait.
Ex. BB, Bb, bb
Ex. Brown eyes or blue
eyes
Genotype(s):
Phenotype:
Genotype:
Phenotype:
CROSS A HOMOZYGOUS PURPLE FLOWER WITH A WHITE FLOWER. PURPLE IS
DOMINANT, WHITE IS RECESSIVE.
B
b
b
B

Cross a homozygous tall (TT) and brown haired (BB)
male with a recessive short (tt) and blonde (bb)
female.
TTBB x ttbb
Co-Dominant (Multiple Alleles):
A type of inheritance when two alleles are equally
dominant and expressed. Ex. Blood Types

There are 3 alleles for blood typing: A, B, O
A
and B alleles are co-dominant
 O allele is recessive
•
Even though “O” is capitalized, it is still considered a recessive
allele.
BLOOD TYPE
GENOTYPE
“A” blood
AA, AO
“B” blood
BB, BO
“AB” blood
“O” blood
AB
OO
CROSS A PARENT WITH “O” TYPE BLOOD WITH A
PARENT WITH HETEROZYGOUS “B” TYPE BLOOD.
SEX-LINKED: A type of inheritance where
certain alleles are found only on one sex
chromosome (X)
Ex. color-blindness, hemophilia, werewolf
syndrome
CARRIER: A female that carries the recessive
sex-linked allele, but does not express the
trait.
CROSS A COLORBLIND MALE WITH A NORMAL
FEMALE.
OBJECTIVE:
Deduce the probable mode of inheritance of
traits (ex. recessive/dominant, sex-linked)
from pedigree diagrams showing
phenotypes.
PEDIGREE ANALYSIS
Male =
Female =
Marriage =
Sibling =
AFFECTED INDIVIDUAL =
Organization Rules:
1. Generations are numbered using Roman numerals, I, II, III,
etc.
2. Children are placed in birth order starting from the left side.
OBJECTIVE:
Describe the differences
between genetic disorders and
infectious diseases.
Disease
Infectious
pathogen caused
disease passed
from one
organism to
another
Genetic
Disease caused by a
genetic inheritance
HIV
Human Immunodeficiency Virus
Pathogen
Symptoms
Treatment
Virus
Generally symptom
free for 8-9 years
No cure, difficult to
develop an HIV vaccine
Later stages result in
weak immune system
and develops into
AIDS.
Patients take multiple
drug treatments that try
to stop the virus from
replicating.
AIDS
Acquired Immunodeficiency Syndrome

CAUSED BY:
a virus called HIV, that attacks White
Blood Cells (CD4)

HOW IS HIV TRANSMITTED?
Direct contact of a mucous membrane or
the bloodstream with a bodily fluid
containing HIV.
ex: blood,semen,vaginal fluid, breast milk
Why can’t we create a
medicine to fight HIV?

HIV replicates at a very fast
rate: 10, 000, 000,000 virons
per day.

HIV differs from many
viruses in that it has a very
high mutation rate . About 1
mutation every 5 seconds.
OBJECTIVES:
-Explain how the processes of genetic
mutation and natural selection are related
to the evolution of species.
-Describe how structural and behavioral
adaptations increase the chances for
organisms to survive in their
environments.
It is not the strongest of the species that survives,
nor the most intelligent that survives.
It is the one that is the most adaptable to change.
-Charles Darwin, Origin of Species
Adaptations (structural and
behavioral):
inherited characteristics that increases
an organisms chance of survival and
opportunity to reproduce in it’s niche.
 Birds---migrate/fly
 Bears---hibernate
 Possums---play
 Desert
south in the winter
in the winter
"dead" to avoid predators
animals---nocturnal/inactive during
the daytime
 Duck---webbed
feet
 Fish---gills
 Giraffe---long
neck
 Beaver---large, pointed teeth
 Whale---blubber
 Cactus---shallow roots
 Snake---flexible jaw
Genetic Change!
Nucleotides or genes of DNA/RNA can change
randomly (mutations). This can lead to a new
variation of an organism, this may or may not
give the organism an advantage to survive.
Charles Darwin: The founder of the theory
Natural Selection and author of “Origin of
Species”
 Natural
Selection: a process by which
individuals that are better suited to their
environment survive and reproduce most
successfully
1.
Overproduction – Each species produces
more offspring than can survive.
2. Genetic Variation – Individuals in the
population have different traits. (ex.
Different fur color, size of claws, length
of tail).
3. Struggle to Survive – The natural
environment can not support all
organisms. This can lead to competition of
food, shelter & mates.
4. Reproduction: The organisms that are
well adapted to their environment
reproduce and pass the favorable traits to
their offspring. Those who survive &
reproduce are considered “the fittest”.
OBJECTIVE:
Explain how the current theory of
evolution provides a scientific
explanation for fossil records of
ancient life forms.
 Fossil:
Preserved remains or evidence of
an ancient organism.
 How
are fossils formed? An organism dies
and is covered by sediments before being
rotted or eaten. It will become part of the
sedimentary layer that becomes rock.
 The
lower the
layer is, the
older the fossil
is.
 The
higher the
layer is, the
younger the
fossil is.
OBJECTIVES:
-
Describe the factors that affect the carrying
capacity of the environment.
-
Explain how change in population density is
affected by emigration, immigration, birth rate
and death rate, and relate these factors to the
exponential growth of human populations.
- Explain how technological advances have
affected the size and growth rate of human
populations throughout history.

Exponential is
growth that would
take place under
ideal conditions
with unlimited
resources.

Logistical is growth
that is eventually
limited to a
number (carrying
capacity) that can
be supported by
environmental
resources.

Carrying Capacity:
The number of
individuals in a
population that an
environment can
support.
Exponential Growth Curve
Logistical Growth Curve
1.
Birth Rate: the amount of births for a given
time period
2.
Death Rate: the amount of deaths for a given
time period
3.
Immigration: movement of organisms INTO an
area occupied by an existing population
4.
Emigration: movement of organisms OUT of an
area where population is located
Definition: A graph that shows a population’s
growth based on AGE and SEX.
Age Groups:
1. Pre-Reproductive= 0-4 through 15-19
2. Reproductive= 20-24 through 40-44
3. Post Reproductive= 45-49 through
80+
There are 3 types of growth patterns:
1. Rapid Positive Growth
2. Slow Positive Growth
3. Negative Growth

http://www.slideshare.net/lntrullin/under
standing-populationpyramids?from=share_email
International Database

http://www.census.gov/ipc/www/idb/count
ry.php