Download Name: Block: ______ Date: MCAS Review: Genetics Broad Concept

Name: _________________________________________ Block: ________ Date: _________________
MCAS Review: Genetics
Broad Concept: Genes allow for the storage and transmission of genetic information. They are a set of
instructions encoded in the nucleotide sequence of each organism. Genes code for the specific sequences
of amino acids that comprise the proteins that are characteristic of that organism.
2.6 Describe the cell cycle and the process of mitosis. Explain the role of mitosis in the formation of new
cells, and its importance in maintaining chromosome number during asexual reproduction.
Vocabulary:

_______________________________________ - producing more of the same kind of organism

________________________________________ - reproduction involving only one parent

____________________________________ - cell division that results in 2 nuclei with the same kind
and number of chromosomes as the original cell

__________________________________________ - division of the cytoplasm

_____________________________________________ - making an exact copy of a DNA molecule

_____________________________________ - period of time between cell divisions

_____________________________________ - period of time from the beginning of one cell
division to the beginning of the next

_______________________________________ - identical strands of DNA which make up
the two part of a chromosome seen during cell division

_______________________________ - part of chromosome where sister chromatids are attached

______________________________ - protein fibers that move chromosomes during cell division
Use the letters below to identify the various stages of the cell cycle.
Period of active cell division - _________________
Interphase - ______________________
M phase - ______________________
S phase - _______________________
G1 phase - _______________________
G2 phase - _______________________
1
Complete the chart telling what happens during the various phases of the cell cycle.
Stage or Phase
What happens?
G1 phase
S phase
G2 phase
mitosis
cytokinesis
Name three reasons why a cell might undergo mitosis.
1. ______________________________________
2. ______________________________________
3. ______________________________________
2.7 Describe how the process of meiosis results in the formation of haploid cells. Explain the importance
of this process in sexual reproduction, and how gametes form diploid zygotes in the process of
fertilization.
Vocabulary:

__________________________________ - having 2 sets of chromosomes (symbol 2n)

__________________________________ - having 1 set of chromosomes (symbol n)

__________________________________ - cell division that halves the chromosome number thus
maintaining the diploid number of chromosomes from one generation to the next

______________________________ - general name for reproductive cell

______________________________ - cell that results from the union of 2 reproductive cells

______________________________ - process by which two cells come together during sexual
reproduction

______________________________ - chromosomes that look alike because they have genes that
control the same characteristics located in the same place on each chromosome

_________________________________ - structure formed when two homologous chromosomes come
together during prophase I of meiosis I

_________________________________ - the exchanging of alleles during prophase I between
homologous chromosomes
What is the overall purpose of meiosis?__________________________________________________________
How many cell divisions are involved in meiosis? _________________________
2
How many gametes are produced from 1 parent cell? ___________________________
Do gametes have one set (haploid #) or 2 sets of chromosomes (diploid #)? __________________________
What is the result of crossing over? _____________________________________________________________
What happens to chromosomes

during meiosis I?
__________________________________________________________________________

during meiosis II?
_________________________________________________________________________
When fertilization occurs how many sets of chromosomes are in the resulting zygote? ________________
What type of cell division changes this one celled zygote into a multicellular organism? _______________
What is the difference between the kind and number of chromosomes:
 in a cell found in your liver and a cell found in your skin?
__________________________________________________________________
 a cell found in your liver and a sperm cell?
__________________________________________________________________
3.1 Describe the basic structure (double helix, sugar/phosphate backbone, linked by complementary
nucleotide pairs) of DNA, and describe its function in genetic inheritance.

DNA - _______________________________________________________________________
_______________________________________________________________________

nucleotide - _________________________________________________________________

double helix - _______________________________________________________________
The discovery of the structure of DNA was a major development in biology. Understanding the
structure has enabled scientists to learn more about how DNA works.
a. Draw the structure of DNA. Be sure to include the three components of
the nucleotides and their positions in a DNA molecule.
b. Complete the complementary side of DNA to the following strand:
T A C A T T A C G A G C A
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3.2 Describe the basic process of DNA replication and how it relates to the transmission and
conservation of the genetic code. Explain the basic processes of transcription and translation, and
how they result in the expression of genes. Distinguish among the end products of replication,
transcription, and translation.
Vocabulary:

replication - __________________________________________________________________________

RNA - ________________________________________________________________________________

transcription - _________________________________________________________________________

translation - ___________________________________________________________________________

mRNA- ______________________________________________________________________________

tRNA- _______________________________________________________________________________

rRNA- _______________________________________________________________________________
Complete the following chart:
Process
Nucleic Acids Involved
End Product
replication
transcription
translation
Below is the DNA base sequence for the normal protein for normal hemoglobin and the mutated base
sequence for sickle cell hemoglobin. As the result of this mutation, the red blood cells that are formed
are sickle-shaped which may cause blockage in the capillaries. Using the codon chart, answer the
questions that follow.
Normal:
GGG CTT CTT TTT
Sickle:
GGG CAT CTT TTT
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1. Transcribe and translate the normal DNA.
2. If the DNA base sequence was mutated and read GGA
CTT CTT TTT instead, would this
result in sickle cell hemoglobin? Explain. ________________________________________________________
____________________________________________________________________________________________
3. Does a mutation in DNA always result in a phenotypic change? Explain your answer using the
evidence you have gathered from this problem. __________________________________________________
_____________________________________________________________________________________
3.4 Distinguish among observed inheritance patterns caused by several types of genetictraits (dominant,
recessive, codominant, sex-linked, polygenic, incomplete dominance, multiple alleles).
3.6 Use a Punnett square to determine the probabilities for genotype and phenotype combinations in
monohybrid crosses.
Vocabulary:

_________________________ - different forms of a gene that control a specific characteristic

_________________________ - what the organism physically looks like

_________________________ - what the 2 alleles are that control a specific characteristic

_________________________ - in the genotype, the 2 alleles are different

_________________________ - in the genotype, the 2 alleles are the same

_________________________ - in the heterozygote, the allele that shows itself


_________________________ - in the heterozygote, the allele that is not allowed to show
itself when a dominant allele is present
_________________________ - type of dominance where one allele is dominant and the
other is recessive
_________________________ - type of dominance where in the heterozygote neither allele
shows itself, physically the organism looks somewhere
in between
_________________________ - the type of dominance where in the heterozygote both
alleles are seen
_________________________ - alleles for a particular characteristic are located on the X
chromosomes
_________________________ - characteristic is controlled by more than one gene

_________________________ - characteristic is controlled by more than 2 alleles




5
Patterns of Inheritance
Most characteristics are controlled by ____________ gene that has _____________ alleles.


Mostly 1 allele is _______________________ and the other is ________________________.
o
example: earlobes
o
alleles:
o
unattached or free lobe is dominant (symbol – F)
o
attached lobe is ________________________________ (symbol - _______)
Sometimes neither allele is dominant. This is called __________________________________.
o
example: width of eyes
o
alleles:
o
eyes far part (symbol – W)
o
eyes near together (symbol - ________)
o
heterozygote (genotype – _______________) physically you see something between
far and near - ____________________________

Sometimes both alleles are dominant. This is called ________________________________.
o
example: shape of red blood cells (hemoglobin)
o
alleles:
o
normal shaped (symbol – N)
o
sickle shaped (symbol – ________)
o
heterozygote (genotype – ____________ ) physically you see both normal and sickle
shaped red blood cells

Sometimes alleles are located on the X chromosome. These are called ___________________.
o
females have _________ X chromosomes
o
o
This means they have __________ alleles that control this characteristic.
males have ____________ X chromosome
o
This means they have __________ allele that controls this characteristic.
o
example: red-green colorblindness
o
alleles:
o
normal is dominant – (symbol – XN)
o
colorblind is recessive – (symbol – ______)
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o
genotypes of individuals
o
females
1. normal (noncarrier) female - __________________
2. carrier female (heterozygote) - ________________
3. colorblind female - _________________
o
males
4. normal male - ________________
5. colorblind male - _______________

Sometimes the characteristics are still controlled by _________ gene but there are more than ________
alleles. This is called ___________________________________ .
o
o
example: ABO blood types
alleles:
o
person has protein A in blood (symbol – IA)
o
person has protein B in blood (symbol – _______)
o
blood has no protein (symbol – i)
o
What is the relationship between IA and IB? They are ____________________________.
o
What is the relationship between i and the other 2 alleles (IA & IB)?
____________________________________________________________________________
o
What are the phenotypes (blood types) of the people whose genotype is:
o
IA IA - ________________________________
o
i i - __________________________________
o
IA IB - ________________________________
o
IB i - _________________________________
(2) What physical characteristics of your peers show a wide variety of phenotypes?
__________________________

_________________________
_________________________
These are controlled by more than 1 gene with 2 alleles controlling each gene. They are referred to as
___________________________________ traits or characteristics. If you were to graph all the different
physical possibilities, there would be many and if arranged from least to most it would resemble a
bell curve.
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Identify the inheritance pattern in the following scenarios.
a. A cross between a purebred animal with brown hairs and a purebred animal with white hairs
produces an animal that is spotted with both brown hairs and white hairs. What type of inheritance
pattern is involved? ___________________________
b. In a cross between individuals of a species of tropical fish, all of the male offspring have long tail fins,
and none of the females possess the trait. Mating two of the F1 fish fails to produce females with the trait.
What type of inheritance pattern is involved? ___________________________
c. Suppose you cross a red flower and a white flower. The petals of the flowers of all the offspring are
pink. What is the inheritance pattern being expressed? _________________________________
d. An ecologist observes that a population of plants in a meadow has flowers that may be red, yellow,
white, pink, or purple. Hypothesize what the inheritance pattern might be. Explain.
____________________________________________________________________________________________
Complete Punnett squares for the following crosses.
a. A dog breeder has two black labs that he breeds every year. He takes careful records of the colors of
offspring produced from the breeding. Over an eight year period, he has recorded 19 chocolate pups and
62 black pups. What are the probable genotypes of the two parents? Show the cross between the two
black labs.
b. In Holstein cattle, spotting of the coat is caused by a recessive allele and solid coat color by a dominant
allele. What types of offspring can occur in a cross between two spotted animals? Show the cross and
phenotype ratios.
c. A rooster with grey feathers is mated with a hen of the same phenotype. Among their offspring 15
chicks are grey, 6 are black and 8 are white. What is the simplest explanation for the inheritance of these
colors in chickens? What offspring would you expect from the mating of a grey rooster and a black hen?
Show the cross and phenotype ratios.
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