Unit 8 science
1.) A dominant allele/trait is one that always shows up more often in a population 2.) An allele is the same as a gene, but merely a different version of the gene 3.) A genotype is the physical expression of the DNA an organism shows 4.) Genetics is the branch of biology that involves the study of how different traits are transmitted from one generation to the next 5.) A heterozygous individual of a dominant/recessive trait will display the dominant trait in their phenotype 6.) For F = furry and f = non furry; a homozygous dominant and a homozygous recessive parent will always have furry children 7.) Pedigrees show how a certain trait relates to the phenotype of each member of a family 8.) Punnett Squares show that it only takes having 4 offspring to come up with all possible combinations of alleles 9.) The law of independent assortment states that ALL traits are inherited separately from one another
1.) T 2.)T 3.)F 4.)T 5.)T 6.)T 7.)T 8.)F 9.)T
What is the difference between a gene and an allele?
A gene is a stretch of DNA or RNA that determines a certain trait. Genes mutate and can take two or more alternative forms; an allele is one of these forms of a gene. For example, the gene for eye color has several variations (alleles) such as an allele for blue eye color or an allele for brown eyes.
What is a Punnett Square? What information can it provide about parents and their offspring?
A punnett square helps us identify which traits the offspring will get and what is recessive and dominants. It can identify the genotype and phenotype of the offspring
Which of the following is an example of a heterozygous individual?
AB
Why do we have to specify 'dominant' or 'recessive' with homozygous but not heterozygous?
Because homo has the same traits while in hetero the dominant trait always comes first
A stretch of DNA that determines a certain trait be describes a(n)?
Chromosome
What is a monohybrid cross?
Cross with "one trait"
Parents that breed and are the same except for one trait would create a:
Dihybrid cross
a genetic trait that appears in every generation of offspring is called
Dominant
What is the difference between a dominant and a recessive allele?
Dominant masks the expression of an alternate gene and appears in the heterozygous condition. Recessive is an allele that is masked by the dominant allele and only appears in homozygous.
in mendals garden pea experiment, he allowed each variety of garden pea to self-pollinate for sever generations to produce the original parents or
F1 generation
Whats the difference between phenotype and genotype?
Genotype is the genetic makeup of an organism while phenotype is the physical characteristics
What do the terms heterozygous and homozygous mean?
Hetero means different while homo means the same
What is the difference between a heterozygote of a trait that is codominant vs incomplete dominant?
It cant be heterozygote and codominant because then both traits would be dominant, in incomplete dominant it also cant be heterozygote because it is neither dominant or recessive.
Law of Segregation
Mendelian law stating that two alleles for each trait separate during meiosis (alleles separate during gamete formation)
What do we mean by 'complex' inheritance or 'non-mendelian' inheritance?
Non mendelian inheritance is when there is any pattern in which traits do not segregate in accordance to mendel's laws
Tallness (T) is dominant over shortness (t) in pea plants. Which of the following represents the genotype of a pea plant that is heterozygous for tallness?
Tt
rule of dominance
a dominant allele will overpower a recessive allele
the unknown geotype of an idvidual witha dominat phenotype can be determined using
a test cross
Which of the following is an example of a homozygous recessive individual?
aa
The specific location of a gene/DNA sequence is called a(n)?
d) Nucleotide
rule of unit factors
each organism has two alleles for each trait
The study of heredity is called
genetics
what do the letter inside the grid of the Punnett square represent
genotypes of the offspring
When an organism has two different alleles for the same gene, it is called:
heterozygous
when an organism has two alleles for a particular trait that are different, the organism is called
heterozygous
If an individual possesses two recessive alleles for the same trait, the individual is said to be
homozygous for the trait
if a characteristic is sex-linked it
occurs only females or males
The _________ is the physical expression of traits
phenotype
the principles of a probability can be used
predict the traits of the offspring produced by genetic crosses
A useful device for predicting the possible offspring of crossed between different genotypes is the
punnett squares
the phenotype of an organisms
the physcial apperance of a trait
hair color and eye color are examples of a person
phenotype
which of the following describe hemophilia
sex-linked trait
When Gregor Mendel crossed homozygous purple-flowered plants with a homozygous white-flowered plants, all the offspring were purple because
th allele for a purple-flowered plants is dominant
law of independent assortment
the law that states that genes separate independently of one another in meiosis (alleles of different traits/genes separate independently from each other)
mendals law of segregation states that
the two alleles for a strait seperate when gametes are formed
if a pea plant were homozygous recessive for height, how would its alleles be represented
tt
An individual heterozygous for a trait and an individual homozygous recessive for the trait are crossed and produce many offspring. These offspring are likely to be
two different phenotype
which of the following describe an organism that has the phenotype Bb
Heterozygous
What is X-linked inheritance? How come it is important to note what traits are inherited on an X-chromosome (as opposed to saying '3rd chromosome linked' etc)?
X-Linked is a inheritance that is attached to a certain sex linked gene in which is only appears in either female or male. It is important to know if it it's sex linked or not because it helps identify who has it and helps infinity if it's possible for an individual to have it.
Genes located on homologous chromosomes may have alternate forms that control different forms of a trait. These alternate forms of a gene are called
alleles
the_______produced by each parent are shown along the ides of a punnet squares
gametes
A female guinea pig homozygous dominant for black fur color is mated with a male homozygous for white fur color. In a litter of eight offspring, there would probably be _____.
2 black, 4 gray, 2 white
For cats, B = black fur b = white fur. A Heterozygous parent mates with a homozygous recessive parent. What are the odds that their kitten is a heterozygote?
2/4
For B = black fur, b = white fur: Cross BB with Bb; which is the accurate phenotype ratio:
2/4 black ; 2/4 white
in mink, brown fur color is dominant to silver-blue fur color. if a homozygous brow mink is mated with silver-blue mink and 8 offspring are produced, how many would be expected to be silver-blue?
3
a couple has 2 children, both of whom are boys. what is the chance that parents next child be be a boy?
50%
When Gregor Mendel crossed a homozygous tall plant with a homozygous short plants, the F1 plants inherited
An allele for tallness from the tall parent and allele for shortness from the short parent
What do the letters on the inside of a Punnett Square represent?
Genotypes of offspring
the father of genetics was
Gregor Mendel
Who was Gregor Mendel and why is he famous?
Gregor mendel worked with pure lines of peas for 8 years he got famous because he looked for different characteristics and identified how they are recessive and dominant
Why did Mendel select Pea Plants for his experiments? What advantage did the plants offer Mendel for his experiment?
He selected peas because they grow quickly and they have many characteristics to look at
What were Mendel's experiments and what data did he collect from them?
He studied a pure line pease and looked for different characteristics in it, his research concluded that the parents influence the the peas characteristics and some characteristics are dominant while others are recessive
the term for a cross that involves just one traits, such as pod shape is called
Monohybric cross
A blue fish mates with a red fish and creates a purple-colored offspring. In these fish, color is inherited in what way?
codominant
What is the difference between codominant and incomplete dominant inheritance?
in incomplete dominance no allele for a trait is dominant, or recessives. In codominant both alleles for a trait are dominant
Gregor Mendal concluded that traits are
inherited through the passing of factors from parents to offspring
Since the allele for colorblindness is located on the X chromosome, colorblindness
is sex-linked
Mendel's finding that the inheritance of one trait had no effect on the inheritance of another became known as the
law of independent assortment
a dogs phenotype can be determined by
looking at the dog
