GENETICS Flashcards
Traits definition
The characteristics that vary between individuals
Phenotype definition:
physical features of the organism
Genotype definition:
the genetic makeup that determines the phenotype
Parental generation (P) definition:
The parents in Mendel’s experiments. These plants are “pure” – they only produce plants with their own phenotype when they are self pollinated
First filial generation (F1) definition:
The offspring of the parental generation
Second filial generation (F2) definition:
The offspring of the first filial generation
What do you think the result was of the breeding of the yellow x green plants? 1. All yellow 2. All green 3. Some yellow peas, some green 4. Yellowish green peas
- All yellow
What do you think the result was of the breeding of the F1 self fertilization?
- All yellow
- All green
- Some yellow peas, some green
- Yellowish green peas
- Some yellow peas, some green
Result from Mendel’s First Experiment:
P generation = all yellow or all green peas
The plants produced pea pods with all yellow peas.
Mendel’s next (second) experiment
Mendel planted the peas and grew up the
plants – these are F1 plants
He allowed these F1 plants to self pollinate themselves
The pollen from the plants fertilized the same plants’ eggs
The plants produced pea pods, with some yellow peas and some green peas (F2).
Results from second exp
The pea pods have some green and some yellow peas.
He counted all the peas from the experiment and he got about 6000 yellow peas and about 2000 green peas. This is a 3:1 ratio.
He did these same experiments over again with other traits and got the same results. Always a 3:1 ratio
Results from both experiments
P generation were all _____ bred to all _____
green , yellow
Results from both experiments
F1 generation were all _____ peas
yellow
Results from both experiments
F2 generation had both yellow and greens (______ ratio)
3:1
The trait that is expressed is the ________ trait
dominant
The trait that is hidden, or not expressed is ______
recessive
In this example (Mendels experiments) the yellow trait is the _____ trait over green which is _____
dominant trait, recessive
At the end of Meiosis II how many chromosomes are there in the cell?
- 23
- 46
- 23
At the end of Meiosis II the chromosomes are in the duplicated state
- Duplicated
- Unduplicated
- Unduplicated
Gene definition:
the part of DNA that codes for a protein
In a pair of homologous chromosomes, each one contains the same genes. These different forms of the same genes are called _____
alleles
Each chromosome in the pair of chromosomes has an _____
allele
If both the chromosomes in the pair have the same allele form, then they are ______ for that trait
homozygous
If the chromosomes in the pair have different alleles they are _______ for this trait
heterozygous
Homologous pair of chromosomes are:
same in size and function
a human male has one pair of non homologous chromosomes, they are the ___ and ____ chromosomes
X, Y
Dominant alleles are written with a ______ letter
capitol
Recessive alleles are written with a ____ letter, always use the same letter
small
In Mendel’s peas, the allele for yellow peas are written as ____ and allele for green peas are written as ____
Y, y
Phenotype definition:
physical features of the organism
Genotype definition:
the genetic makeup that determines the phenotype
The phenotype for a yellow pea is yellow color, and the genotype is ____ or ___
YY or Yy
The phenotype for a green pea is green color, and the genotype is ____
yy
If you cross pollinated homozygous purple plants with homozygous white plants (P generation) and the result was offspring that were all purple (F1). Which allele is dominant?
A. Purple
B. White
A. Purple
What is the genotype of the P (parental) generation (the homozygous white and homozygous purple)
- PP and pp
- Both Pp
- Both PP
- Both pp
- PP and pp
What is the genotype of the F1 (when you cross PP x pp cross) generation
- PP and pp
- All Pp
- All PP
- All pp
- PP, Pp, pp
- All Pp
F1s self fertilize, What is the genotype of the F2 generation
- PP and pp
- PP, pp, Pp
- All Pp
- All PP
- All pp
- PP, pp, Pp
_________ disorders are only those disorders that are controlled by the X or Y genes
Sex-linked
All other chromosomes are _______
autosomal chromosomes
Autosomal recessive disorders definition:
These are disorders that are controlled by DNA on any of the non-sex chromosomes (22 homologous autosomal chromosomes)
These are recessive disorders so they are only expressed if the person is _______ for the allele
homozygous
sickle-cell anemia, cystic fibrosis, albinism, phenylketonuria are examples of autosomal ______ disorders
Recessive
Sickle-cell disorder is due to a _________
point mutation in the DNA that controls the formation of the hemoglobin protein – causing a misshaped red blood cells
A _______ is a person that does not express a recessive disorder but carries the allele for the disorder (heterozygous)
carrier
To determine the chances that two carriers will pass on the disorder – do _______
a Punnetts square
If two people that are heterozygous for sickle cell anemia have children, what is the chance they will have a child with sickle cell anemia?
- 0
- 1/4
- 1/2
- 1
- 1/4
carriers of sickle-cell anemia have greater protection from _____ symptoms
malaria
People who are heterozygous for sickle cell anemia are able to produce both the _____ and ______ hemoglobin proteins
normal and abnormal
The abnormal protein of sickle cell anemia protects against the affects of _____
malaria
If two people that are heterozygous for sickle cell
anemia have children, what is the chance they will
have a child that is a carrier for sickle cell anemia?
1. 0
2. 1/4
3. 1/2
4. 1
- 1/2
Dominant Autosomal disorders are those disorders control by the _____
chromosomes
non-sex
These dominant disorders will be expressed when the person has ______.
one or two alleles for the disorder
Huntington disorder, cholesterolemia, Achoo syndrome are all examples of:
Dominant Autosomal Disorders
Huntington’s disease – It is a degenerative disease that affects the ______.
cerebral cortex region of the brain
Huntington’s disease –initial symptoms are abrupt, jerky movements, these symptoms typically develop in _____. Late in the disease dementia occurs.
middle age
Huntingtons disorder- It is caused from a repeat of three bases of
the DNA on ____
chromosome 4.
One parent has Huntington's and is heterozygous, your other parent is normal. What is the chance that you will have Huntington’s? A. 0% (0/4) B. 25% (1/4) C. 50% (2/4) D. 75% (3/4)
C. 50% (2/4)
X-linked recessive traits are mainly seen in males – Why?
Males only have one X chromosome, so if there is a trait on the X chromosome and they inherit the recessive allele, then they will express the trait.
color blindness, hemophilia, muscular dystrophy are examples of ______
X-linked disorders
Color blind people can not distinguish between certain shades of ____ and _____
greens and reds
In color blindness the proteins in pigments that absorb green and red light are controlled by DNA on the ____ chromosome
X
There are two alleles for color blindness – the _____ one produces the proteins, the ______ allele does not.
dominant, recessive
color blindness is a ______ disorder which means that it will only express if it is homozygous for the recessive allele
recessive
Red-green color blindness is due to a sex-linked recessive allele on the X
chromosome. Two normal visioned parents produce a color-blind son. How did that happen?
the mom is a carrier for color blindness, she passed that X onto her son
What is the chance the couple could have a color blind daughter? A. 1/4 B. 2/4 C. 3/4 D. 0/4 (none)
D. 0/4 (none)
Sickle cell anemia is a recessive autosomal disorder, if a woman, whose father had SCA, marries a man with SCA, she does not have the disorder, what is the probability of their child will have SCA
- 0
- 1/4
- 1/2
- 1
- 1/2
Two people who are both heterozygous for Huntington’s have a child, what is the chance the child will have Huntingtons?
- 0
- ¼
- ½
- ¾
- 1
- ¾
Men show traits of a recessive disorder because:
Because unlike girls men only have one X so if they have an abnormality or a recessive trait on the X chromosome they do not have another X to balance it out like girls do
If you are a girl, you need ____ to have the color blindness trait to have it
both X’s, men only need one to have it
Men ____ (can/cannot) be carriers for X linked disorders?
Cannot because they only have one X, so they either have the disorder or they don’t. Women can have the disorder or can be carriers for the disorder
In order for a recessive disorder to be expressed, a person must be ____
homozygous, meaning they have to have both lowercase letters
In terms of sickle cell, they need to have the ss in order for the disorder to be expressed
A color blind man marries a woman who is a carrier of color blindness but is not color blind, what is the chance they will have a color blind child?
- 0
- ¼
- ½
- ¾
- 1
- ½
Incomplete Dominance definition:
results from a cross in which each parental contribution is genetically unique and gives rise to progeny whose phenotype is intermediate. Incomplete dominance is also referred to as semi-dominance and partial dominance.
Red is dominant, but not completely dominant so RR = red, rr = white, but Rr = pink
co-dominance definition:
Here both the alleles are expressed in heterozygous organisms
What does your blood type refer to?
It is the type of proteins on the surface of the blood cells.
There are two main proteins on blood cells:
A and B, neither type is dominant over the other
The _____ pair of chromosome in humans contains the gene that codes for these proteins that make up blood type. Each chromosome in the pair will have a different gene or allele for the protein.
9th
If the parents have type A (homozygous) and type O blood, what are the phenotypes of the offspring
A. Type A
B. Type B
C. Type AB
D. Type O
A. Type A
If the parents have type AB and type O blood, what are the phenotypes of the offspring
A. Type A B. Type B C. Type AB D. Type O E. Type A and B F. Type AB, B and A
E. Type A and B
The husband is type A and the wife is type B. The baby is type O, should the husband be worried?
A. Yes, get a paternity test
B. No, trust your wife
B. No, trust your wife
The husband is type AB and the wife is type B. The baby is type O, should the husband be worried?
A. Yes, get a paternity test
B. No, trust your wife
A. Yes, get a paternity test
The phenotype is not completely controlled by______
genes
The color of Hydrangea flowers depends on the ______ Acidic soil produces blue flowers, basic soil produces pink flowers
soil.
_______ are disorders where a person has an abnormal number of
chromosomes.
Aneuploidy
Gametes should have_____ total chromosomes so when two gamete meet the offspring will have _____ chromosomes
23, 46
Down syndrome is caused by _____
aneuploidy
People with down syndrome have _____ of the 21st chromosome instead of the normal two chromosomes
three
During _____ when there is crossing over or at other times during interphase or Meiosis the chromosomes may be damaged.
Meiosis I
Examples of types of damage to chromosome structures include:
deletion, inversion, translocation, and duplication
Causes of chromosome damage or structure can include:
radiation, chemicals or chance
Cri-du-chat syndrome is caused by a _____ in part of chromosome number 5
deletion
Children with this disorder have a defect in their _____ that causes them to make cat sounds. This effect goes away by the age of 4
larynx
What is an example of an autosomal recessive disorder? A. Downs B. Huntington C. Sickle cell anemia D. Color blindness E. Cri du chat
C. Sickle cell anemia
What is an example of a recessive X linked disorder?
- Down’s syndrome
- Color blindness
- Huntingtons
- Cri-du-chat
- Color blindness
What is an example of a dominant autosomal genetic disorder? A. Down’s syndrome B. Color blindness C. Huntingtons D. Cri-du-chat
C. Huntingtons
What is an example of a disorder due to missing a part of chromosome #5?
- Down’s syndrome
- Color blindness
- Huntingtons
- Cri-du-chat
- Cri-du-chat
What is an example of a disorder due to aneuploidy?
- Down’s syndrome
- Color blindness
- Huntingtons
- Cri-du-chat
- Down’s syndrome
If the parents have type A (homozygous) and type B (homozygous) blood, what are the phenotypes of the offspring A. Type A B. Type B C. Type AB D. Type O E. Type and type B
C. Type AB
Brown eyes are dominant over blue eyes, it is an autosomal trait. A brown-eyed couple gets married, the husband is homozygous for brown
eyes and the wife is heterozygous. What is the chance they will have a blue eyed child?
A. ¼
B. ½
C. ¾
D. 4/4
E. 0/4
E. 0/4
Brown eyes are dominant over blue eyes, it is an
autosomal trait. Two blue eyed people have a
child. What is the chance they will have a brown
eyed child?
A. ¼
B. ½
C. ¾
D. 4/4
E. 0/4
E. 0/4
Cystic fibrosis has been found to be inherited through a recessive
autosomal allele. A man with cystic fibrosis marries a woman who does
not have cystic fibrosis, but her mother had the disease. What is the
chance their child will have CF?
A. ¼
B. ½
C. ¾
D. 4/4
E. 0/4
B. ½
A mother has blood type O, her child is type O. She claims a man of type AB is the father. Could he be?
A. Yes
B. No, get a paternity test
B. No, get a paternity test
A mother has blood type A, her child is type O. She claims a man of type AB is the father. Could he be?
A. Yes
B. No, get a paternity
test
B. No, get a paternity
test
A mother has blood type A, her child is type O. She claims a man of type B is the father. Could he be?
A. Yes
B. No, get a paternity test
A. Yes
Red-green color blindness is due to a X-linked recessive allele on the X
chromosome. A color blind father and a normal visioned mother (she is
heterozygoes) have a child, what is the chance the child will be color
blind?
A. ¼
B. ½
C. ¾
D. 4/4
E. 0/4
B. ½