Genetics Exam 3

Glucose-6-phosphate dehydrogenase deficiency (G6PD) is inherited as an X-linked recessive trait in humans. A woman, Harriet, whose father suffered from G6PD has children with a normal man, Terence. What percentage of their daughters is expected to be G6PD affected

0%

Assume that long earlobes in humans are an autosomal dominant trait that exhibits 30% penetrance. A person who is heterozygous for long earlobes mates with a person who is homozygous for normal earlobes. What is the probability that their first child will have long earlobes? Use two decimal places for the answer.

0. 15

Suppose two parents, a father with the genotype AaBbCcDdee and a mother with the genotype aabbCcDDEe, want to have children. Assume each locus follows Mendelian inheritance patterns for dominance. What proportion of the offspring will have the same genotype as the father? Round your answers to two decimal places.

0.03

Suppose two parents, a father with the genotype AaBbCcDdee and a mother with the genotype aabbCcDDEe, want to have children. Assume each locus follows Mendelian inheritance patterns for dominance. What proportion of the offspring will phenotypically resemble the mother? Round your answers to two decimal places.

0.09

Suppose that goats have one gene that codes for color, where A is brown and a is white. The goats also have another gene that codes for height, where B is tall and b is short. If these two genes are unlinked, what is the probability that a cross between Aa Bb × Aa bb parents will produce two out of six offspring that are white and tall? Enter your answer as a decimal to three places, rather than as a percentage.

0.137

0.25

0.25

Huntington's disease is an inherited autosomal dominant disorder that can affect both men and women. Imagine a couple has had seven children, and later in life, the husband develops Huntington's disease. He is tested and it is discovered he is heterozygous for the disease allele, Hh. The wife is also genetically tested for the Huntington's disease allele, and her test results show she is unaffected, hh. What is the probability that any four of the seven children will have Huntington's disease?

0.273

A very rare dominant allele that causes the little finger to be crooked has a penetrance value of 80%. In other words, 80% of heterozygotes carrying the allele will have a crooked little finger. If a homozygous unaffected person has children with a heterozygote carrying this mutant allele, what is the probability that an offspring will have little fingers that are crooked?

0.4 or 4/10

Suppose two parents, a father with the genotype AaBbCcDdee and a mother with the genotype aabbCcDDEe, want to have children. Assume each locus follows Mendelian inheritance patterns for dominance. What proportion of the offspring will phenotypically resemble neither parent? Round your answers to two decimal places.

0.81

How can changes in the DNA sequence can lead to differences in the phenotype?

1 trait 2+ genes multiple phenotypes possible vast majority of our traits are complex, meaning many genes are involved and input from environment

In Drosophila melanogaster wings are typically long and rounded, but a recessive mutation, vestigial, causes short shriveled wings. A true-breeding wild type fly was mated to a true-breeding vestigial fly and all of the F1 offspring had wild type phenotype. The F1 flies were mated to each other to produce the F2 and produced the following phenotypes in the offspring: What is the Chi-square value for this cross assuming typical Mendelian inheritance?

1.83

Hemophilia (reduced blood clotting) is an X-linked recessive disease in humans. A woman with hemophilia mates with a man who exhibits normal blood clotting. What is the probability that their child will have hemophilia?

1/2

Huntington's disease is an inherited autosomal dominant disorder that can affect both men and women. Imagine a couple has had seven children, and later in life, the husband develops Huntington's disease. He is tested and it is discovered he is heterozygous for the disease allele, Hh. The wife is also genetically tested for the Huntington's disease allele, and her test results show she is unaffected, hh. What is the probability that the first child of this couple will have Huntington's disease?

1/2

In fruit flies, a maternal effect gene called bicoid determines the correct development of the head in embryos (bicoid +). The recessive, nonfunctional allele (bicoid -) results in no head formation and embryos with an anus on both ends. A heterozygous male mates with a homozygous recessive female. What proportion of their offspring will develop normally?

1/2

A common aster flower has blue or pink color based on a single gene with a simple dominant-recessive relationship. A true-breeding blue-flowered plant was crossed with a true-breeding pink-flowered plant. All of the F1 offspring had pink flowers. If the F1 offspring are crossed to each other, what proportion of blue-flowered plants do you expect in the following generation?

1/4

Suppose that goats have one gene that codes for color, where A is brown and a is white. The goats also have another gene that codes for height, where B is tall and b is short. If these two genes are unlinked, what is the probability that a cross between Aa Bb × Aa bb parents will produce offspring that are white and tall?

1/8 (Solve by making a 16 box Punnett square)

Red-green color blindness is an X‑linked recessive trait in humans. Polydactyly (extra fingers and toes) is an autosomal dominant trait (for this question, assume the standard Mendelian dominant/recessive pattern). Martha has normal fingers and toes and normal color vision. Her mother is normal in all respects, but her father is color blind and polydactylous. Bill is color blind and polydactylous. His mother has normal color vision and normal fingers and toes. When answering the given question, consider that the answers include the proportions of only some of the possible phenotypes; other phenotypes are also expected to occur but are not included. If Bill and Martha marry, what proportions of children with specific phenotypes would they be expected to produce?

1/8 color‑blind girls with polydactyly, 1/8 boys with normal vision and normal fingers

Fruit flies can have red or purple eye color and the body may be covered with wild-type straight bristles or short, curly bristles referred to as singed. A true-breeding red-eyed female fly with singed bristles mated with a true-breeding purple-eyed male fly with wild-type bristles. All of the F1 offspring have red eyes and wild-type bristles. The F1 offspring are mated with each other, and you observe a total of 1000 offspring of the following phenotypes: 68 purple/singed bristles;193 purple/wild-type bristles;181 red/singed;558 red/wild-type bristles. What was the expected number of purple-eyed flies with wild-type bristles?

187

In red dragons, scales can come in solid or spotted patterns. When a true-breeding solid patterned dragon mates with a spotted dragon all offspring have a solid scale pattern. Two solid patterned dragons mate and produce both solid and spotted baby dragons. If they produce five offspring, what is the probability that they will have 2 spotted baby dragons?

2.5

Manx cats have a short tail or no visible tail at all due to a single gene, and the manx allele is lethal in the homozygous state. A breeder that has been raising manx cats for many years has produced 36 total kittens from crosses between two manx cats. How many of these kittens do you expect have the manx phenotype?

24

In certain species of summer squash, fruit color is determined by two interacting genes. A dominant allele, W, determines white color, and a recessive allele (w) allows the fruit to be colored. In a homozygous ww individual, a second gene determines fruit color: G (green) is dominant to g (yellow). A dihybrid squash, WwGg, is selfed and produces 320 offspring. How many offspring are expected to have the white phenotype?

240

Suppose that allele D produces big ears and allele d produces normal ears. A heterozygous male with the Dd genotype mates with a homozygous female with the dd genotype. Big ears is an autosomal dominant trait expressed with 50% penetrance. Determine the probability that their offspring will have big ears. Report your answer as a percentage without decimal points. For example, if your answer was a probability of 0.3, convert that to a percentage by multiplying by 100%, and then you would enter 30 for the answer.

25

In horses, the Overo gene, Ov, produces a white splotch pattern on the coat. The overo phenotype is seen only when a horse has one Ov copy, Ovov. Horses with two Ov copies, OvOv, die soon after birth and are called white overo because they are completely white. Horses with no Ov copies are solid colored, ovov. The Leopard complex gene, Lp, shows incomplete dominance and controls white spotting. One Lp allele, Lplp, produces the leopard phenotype, in which there are spots everywhere. Two Lp alleles, LpLp, produce the fewspot phenotype, in which the horse is mostly white with colored spots. Two lp alleles, lplp, produce a solid color. A horse that is both overo and leopard is called pintaloosa, and these horses are spotted with splotches. A horse that is overo and fewspot is considered fewspot because the white areas from Lp is indistinguishable from the white from Ov. Suppose that 16 pairs of pintaloosa horses have one offspring per pair. How many of each phenotype would be expected? Determine the number out of 16 expected for each phenotype. Only count phenotypes for offspring expected to live past one week of age.

3 fewspot __4__ pintaloosa __1__ solid

[Continuing from the previous question concerning how the baldness phenotype is expressed in humans.] Sandra and Mike have four children and later in life both Sandra and Mike experience baldness. Neither of Mike's parents were bald, but Sandra's father was bald. What is the probability that their sons will go bald?

3/4

Manx cats have a short tail or no visible tail at all due to a single gene, and the manx allele is lethal in the homozygous state. A breeder that has been raising manx cats for many years has produced 60 total kittens from crosses between two manx cats. How many of these kittens do you expect have the manx phenotype?

30

In Drosophila melanogaster wings are typically long and rounded, but a recessive mutation, vestigial, causes short shriveled wings. A true-breeding wild type fly was mated to a true-breeding vestigial fly and all of the F1 offspring had wild type phenotype. The F1 flies were mated to each other to produce the F2 generation and produced the following phenotypes in the offspring: What is the expected number of wild type offspring from this cross?

315 Look at picture on phone

Both genetic and nongenetic factors cause the congenital skeletal abnormality known as clubfoot, which occurs with a worldwide incidence of about 1 in 1000 births. Gurnett et al. identified a family in which clubfoot occurred as an autosomal dominant trait due to a mutation in the PITXI gene. DNA testing revealed that 11 people in the family carried the PITXI mutation, but only eight of these people had clubfoot. Calculate the penetrance of the PITXI mutation in this family.

73

What is a monohybrid cross?

A cross between individuals heterozygous for a single character

A maternal effect gene exists in a dominant N (normal) allele and a recessive n (abnormal) allele. What would be the ratios of genotypes and phenotypes for the offspring of the following crosses: A) nn female x NN male B) NN female x nn male C) Nn female x Nn male

A) Nn= genotype, abnormal = phenotype B) Nn = genotype, normal = phenotype C) 1 NN:2Nn : 1nn = genotype, all normal =phenotype

In humans, oculocutaneous (OCA) albinism is a collection of autosomal recessive disorders characterized by an absence of the pigment melanin in skin, hair, and eyes. That is, normal pigmentation (𝐴) is dominant over albino characteristics (𝑎) . For this question, assume the phenotype is determined by a single gene with two alleles. If both parents have normal pigmentation, what are all of the possible genotypes that may be observed in their offspring?

AA, Aa, or aa

In the pedigree provided, assume that A indicates a dominant allele and a indicates a recessive allele. What is the genotype of individual III-5?

Aa

[continued from previous question] If Terence was affected by G6PD, select the true statements about their children.

All unaffected daughters would be carriers

What is heterozygote?

An individual organism possessing two different alleles at a locus

What is homozygote?

An individual organism possessing two of the same alleles at a locus

A species of tree frog shows different color phenotypes, with some frogs having bright green skin, some with pale yellow skin, and some with an intermediate pale green skin. Upon closer examination at the cellular level, you discover that the pale green frogs have about half the amount of proteins functioning to produce pigment. This inheritance pattern is most likely

Co-dominance

Zygote to Adult

Diploid (2n) 2 copies of each chromosome

Setting up crosses --> separating alleles into gametes

Every gene exists in 2 copies in somatic (body) cells Every gamete (sex cell) gets 1 copy of each gene Sperm and egg each have 23 chromosomes

Gametes

Haploid (1n) 1 copy of each chromosome

Is Dominant homozygous or heterozygous?

Heterozygous

Miniature wings, Xm, in Drosophila melanogaster result from an X‑linked allele that is recessive to the allele for long wings, X+. Match the genotypes for each parent in the crosses below - data for offspring of these parents is given.

Look for picture of answers and chart on phone

Breed two manx cats together, and you get 2 manx kittens for every 1 normal kitten. What are the genotypes of the manx and non-manx kittens?

Manx= heterozygous and dominant non-manx = homozygous and recessive Parents are heterozygous Lethal would always be the dominant

In eukaryotes, extranuclear inheritance occurs when genetic information is transmitted by mechanisms other than through nuclear DNA. Mitochondrial DNA (mtDNA) is an example of one mechanism by which extranuclear inheritance can occur. Select the statements that correctly describe mtDNA.

Mitochondrial chromosomes contain genes that are involved in oxidative phosphorylation. mtDNA organization is more similar to that of prokaryotes than eukaryotes.

What is incomplete penetrance?

Not all individuals with a mutant genotype show the mutant phenotype population level; % of individuals with a genotype that express the expected phenotype

What blood types are possible among the children of a cross between a man who is blood type A and a woman of blood type B?

O, AB, A, B = possible blood types Can get all 4 blood types if both parents are heterozygous if 1 parent is homozygous it will limit the blood types

In 1958, two scientists, R.M. Cooper and J.P. Zubek, conducted an experiment using rats in a maze. They took a group of rats and put them in a maze, recording which were able to solve the maze the quickest. The faster rats were bred together and the slower rats were bred together for a few generations until there were two distinct groups of rats, the bright rats and the dull rats, respectively. Next, groups of the dull and bright rats were raised in different environments. An enriched environment contained toys and colors and a depressing environment was simply a cage with no toys or colors. The different experimental groups were (bright, enriched), (bright, depressing), (dull, enriched), (dull, depressing). After being raised in different environments, the rats were challenged with the maze again yielding the results indicated in the table, where changes were based on the bright and dull rats' initial performance. What genetic phenomena best explains the change in performance of the bright rats raised in a depressing environment?

Performance can be attributed to the interaction between the rats' genes and the environment in which they were raised.

White (w) coat color in guinea pigs is recessive to black (W). In 1909, W. E. Castle and J. C. Phillips transplanted an ovary from a black guinea pig into a white female whose ovaries had been removed. They then mated this white female with a white male. All the offspring from the mating were black in color (W. E. Castle and J. C. Phillips, 1909, Science 30:312-313). Which statement explains the results of this cross?

The color of the offspring was determined by genes in the transplanted ovary, not the genes of the female who gave birth.

What is the maternal effect?

The genotype of the mother determines the phenotype of the offspring

For the previous question regarding vestigial wings in D. melanogaster, what can you conclude from your chi-square test results?

These results are consistent with our expectations under Mendelian inheritance

How is a true breeding round‑seeded pea plant different from a hybrid round‑seeded pea plant?

They have the same phenotype but different genotypes.

Phenylketonuria (PKU) is a disease that results from a recessive gene. Two normal parents produce a child with PKU.

What is the probability that their next child will have PKU? 1/4 What is the probability that a sperm from the father will contain the PKU allele? 1/2 What is the probability that an egg from the mother will contain the PKU allele? 1/2 What is the probability that their next child will be heterozygous for the PKU gene? 1/2

In watermelons, bitter fruit (B) is dominant over sweet fruit (b), and yellow spots (S) are dominant over no spots (s). The genes for these two characteristics assort independently. A homozygous plant that has bitter fruit and yellow spots is crossed with a homozygous plant that has sweet fruit and no spots. The F1 are intercrossed to produce the F2.

What will the phenotypic ration in the F2? 9/16 bitter fruit, yellow spots;3/16 bitter fruit, no spots;3/16 sweet fruit, yellow spots;1/16 sweet fruit, no spots If an F1 plant is backcrossed with the bitter, yellow‑spotted parent, what phenotypes and proportions are expected in the offspring? All bitter fruit with yellow spots If an F1 plant is backcrossed with the sweet, non-spotted parent, what phenotypes and proportions are expected in the offspring? 1/4 bitter fruit, yellow spots;1/4 bitter fruit, no spots;1/4 sweet fruit, yellow spots; 1/4 sweet fruit, no spots

In certain species of summer squash, fruit color is determined by two interacting genes. A dominant allele, W, determines why color, and a recessive allele (w) allows the fruit to be colored. In a homozygous (ww) individual, a second gene determines fruit color: (G) green is dominant to g (yellow). A white squash and a yellow squash were crossed, a the F1 generation yielded approximately 50% white fruit and 50% green fruit, What are the genotypes of the parents?

White Squash: WwGG Yellow Squash: wwgg

White (w) coat color in guinea pigs is recessive to black (W). In 1909, W. E. Castle and J. C. Phillips transplanted an ovary from a black guinea pig into a white female whose ovaries had been removed. They then mated this white female with a white male. All the offspring from the mating were black in color (W. E. Castle and J. C. Phillips, 1909, Science 30:312-313). Select the genotype of the offspring from this cross.

Ww

In fruit flies, long wings (W) are dominant over short wings (w), and brown pigments (N) are dominant over yellow pigments (n). Each individual possesses two alleles for each trait. If a fly that is homozygous dominant for both traits is crossed with a fly that is homozygous recessive for both traits, what is the predicted genotype of the offspring?

WwNn

Baldness in humans is a trait that is dominant in men and recessive in women. On which chromosome will we find the gene associated with this trait?

X Chromosome

Suppose that a rabbit breeder notices two individuals in a litter with large, round noses and names this trait the clown trait. He obtains another rabbit that has a long, thin nose and names it the Pinocchio trait. After breeding the rabbits with unusual nose shapes to wild‑type individuals for several generations, he decides to cross rabbits from families with a history of the clown and Pinocchio traits. The first litter from this cross results in individuals of four phenotypes. The phenotypes are clown, Pinocchio, wild‑type, and heart‑shaped noses. The pedigree illustrates the inheritance of these traits. Individuals 1 and 4 are siblings and are known to come from a true‑breeding wild‑type line. What is the most likely mode of inheritance for the clown nose?

X-linked recessive

The Talmud, an ancient book of Jewish civil and religious laws, states that if a woman bears two sons who die of bleeding after circumcision (removal of the foreskin from the penis), any additional sons that she has should not be circumcised. The bleeding is most likely due to the X‑linked disorder hemophilia. Furthermore, the Talmud states that the sons of her sisters must not be circumcised, whereas the sons of her brothers should be. Is this religious law consistent with sound genetic principles?

Yes, the woman is a carrier and half of her sons will be affected. Her sisters may also be carriers, but her brothers' sons will get their X chromosomes from their mothers, who are unlikely to be carriers of the allele.

The dominance pattern of a gene can be determined from the phenotypes of the parents and offspring. In the examples below, assume that each parent is homozygous for the specific allele and that the progeny are heterozygous. Classify each example as either complete dominance, incomplete dominance, or codominance.

_Codominance A red snake mates with a yellow snake and the progeny are brown. Close inspection of cells from the scales shows both red and yellow pigments present that when viewed from far away look brown. __Incomplete Dominance__ A mother with straight hair and a father with curly hair have a son with wavy hair. __Complete Dominance (simple Mendelian)__ A pea plant with all purple flowers and a pea plant with all white flowers produce a pea plant with all purple flowers. __Incomplete Dominance__ A black sheep and a white sheep produce a gray lamb. __Codominance_ A mother with type A blood and a father with type B blood have a daughter with type AB blood

Suppose that in goats, an independently sorting autosomal allele that produces a bearded phenotype is dominant in males and recessive in females. The symbol Bb represents the bearded allele and B+ represents the beardless allele. The autosomal allele for a black coat (W), which also independently assorts, is dominant over the allele for white coat (w). Match each set of progeny phenotypes and proportions to the parental cross that produced that set. Note that not all possible phenotypes are shown for each cross.

_Females: all beardless, 3/4 blackMales: all bearded, 1/4 white___ B+B+ Ww male × BbBb Ww female __Females: 1/4 bearded, blackMales all bearded, 1/2 white__ B+Bb Ww male × BbBb ww female _Females: 9/16 beardless, blackMales: 9/16 bearded, black__ B+Bb Ww male × B+Bb Ww female __Females: 1/8 bearded, blackMales: 1/8 beardless, white__ B+Bb Ww male × B+Bb ww female

Suppose a species of tulip has three alleles for the gene that codes for flower color. The 𝐶𝑅 allele produces red tulips, the 𝐶𝑝 allele produces purple tulips, and the 𝐶𝑤 allele produces white tulips. 𝐶𝑅 is dominant over 𝐶𝑝 and 𝐶𝑤 , and 𝐶𝑝 is dominant over 𝐶𝑤 .For each cross, determine the expected phenotype ratio of offspring flower color.

__2 red: 2 purple: 0 white__ 𝐶𝑅𝐶𝑝 X 𝐶𝑝𝐶𝑤 __2 red: 1 purple: 1 white__ 𝐶𝑅𝐶𝑤 X 𝐶𝑝𝐶𝑤

An allelic series determines coat color in rabbits: C (full color), cch (chinchilla, gray color), ch (Himalayan, white with black extremities), and c (albino, all white). The C allele is dominant over all others, cch is dominant over ch and c, ch is dominant over c, and c is recessive to all other alleles. This dominance hierarchy can be summarized as C > cch > ch > c. The rabbits in the table are crossed and produce the progeny shown.

__Cc X Cc__ Cross E _Cc X ch c___ Cross D _Cc X cc___ Cross A __chc X cc__ Cross B _Ccch X cc___ Cross C

Leigh's disease is a mitochondrially inherited disease with symptoms that include seizures, fatigue, impaired reflexes, breathing problems, and ataxia. The pedigree shows the presence of Leigh's disease in three generations. Individual 4 had one daughter and two sons, and individual 6 had two daughters and one son. Which of the individuals indicated with red question marks are affected by Leigh's disease?

__affected__ Individual III-10 __affected__ Individual II-4 __unaffected_ Individual II-7 __affected_ Individual II-5

What are biochemical pathways?

a series of reactions in which the product of one reaction becomes the substrate for the next reaction

Penile hypospadias, a birth defect in male humans in which the urethra opens on the shaft instead of at the tip of the penis, results from an autosomal dominant gene in some families. Females who carry the gene show no effects. What type of trait is this birth defect an example of?

a sex‑limited trait because the defect occurs only in males and the gene involved is autosomal

Suppose there is a vial containing a single generation of flies from a cross. There is an interesting phenotype where many individuals have abnormally long hairlike bristles, sensory organs extending from the dorsal thorax, as opposed to the short wirelike wild‑type bristles among the other siblings. References state that this mutant has a dominant mutation called Suave (Su) and that the phenotype of flies that are heterozygous or homozygous for Su appear phenotypically identical. Which fly should be crossed to a Suave male from this vial in order to generate progeny that help determine the male's genotype?

a wild-type female sibling

In humans, oculocutaneous (OCA) albinism is a collection of autosomal recessive disorders characterized by an absence of the pigment melanin in skin, hair, and eyes. That is, normal pigmentation (𝐴) is dominant over albino characteristics (𝑎) . For this question, assume the phenotype is determined by a single gene with two alleles. If both parents display the albino phenotype, what are all of the possible genotypes that may be observed in their offspring?

aa

Hemophilia in humans is due to an X-chromosome mutation. What will be the results of mating between a normal (non-carrier) female and a hemophiliac male?

all sons are normal and all daughters are carriers

Possible two-Gene Interactions

alternative biochemical pathways referred to as "epistasis" - one gene makes the phenotype of another gene

What is a characteristic or character?

an attribute or feature possessed by an organism

What is a gene?

an inherited factor (encoded in the DNA) that helps determine a characteristic

Continue from the previous question using the pedigree for rabbit nose shape (clown, Pinocchio, wild type, and heart-shaped). What is the most likely mode of inheritance for the Pinocchio nose?

autosomal dominant

In Labrador retrievers, coat color is controlled by two genes. One gene determines black (B_) or brown (bb) hair. However, if the second gene is homozygous recessive (ee), the coat color is yellow. A brown dog was mated to a yellow dog and they produced 4 black and 3 brown puppies. What were the genotypes of the brown and yellow parents, respectively?

bbEE X BBee

What is the complementation test?

comparing the results of the 2 mutant types with the same or similar phenotypes Usually the trait is a result of a multi-step biochemical pathway

Gregor Mendel

discovered the principles of heredity while studying pea plants used an experimental approach and analyzed results mathematically studied easily differentiated characteristics

What are lethal alleles?

distinct ratio not seen in other situations 2:1 phenotypic ratio because of essential vs nonessential genes 2 copies of dominant allele is lethal

What is genomic imprinting?

expression of a gene depends on which parent each allele comes from genes are silenced from one parent and active from the other

How does the heterogametic sex differ from the homogametic sex?

gametes of the heterogametic sex have different sex chromosomes; gametes of homogametic sex have the same sex chromosomes

Continue from the previous question with the pedigree for rabbit nose phenotype. A careless rabbit sitter leaves several cages open, and a female rabbit mates with an unidentified male. The breeder sends DNA samples from each of the offspring whose fathers are unknown and DNA from individuals IV‑5 through IV‑10 to a genetics lab. The lab staff test the samples for several genes with suspected effects on nose shape. The gel displays the results of genetic testing for the two polymorphic genes detected. The individuals whose father is unknown are labeled A, B, C, and D. What is the phenotype of individual D?

heart-shaped

What is co-dominance?

heterozygote phenotype also sometimes seems "between" two homozygotes, but is really both of the phenotypes expressed at the same time

What is incomplete dominance?

heterozygote phenotype is between the two homozygotes

Is Recessive homozygous or heterozygous?

homozygous

Biochemical Pathways Includes

most traits are more complex than a single one many of our phenotypes are produced by a series of reactions directed by several different enzymes (each encoded by a different gene)

What is pleiotropy?

one gene affects multiple phenotypes within an individual Example: Cystic Fibrosis

What is an allele?

one of two or more alternative forms of a gene

What is cytoplasmic inheritance?

only applies to DNA not held in the nucleus mitochondria and chloroplasts most commonly passed from mother to all offspring, father's organelles do not get passed on

Meiosis produces what?

produces gametes

What is a sex-linked trait?

refers only to genes on the sex chromosomes ( X or Y linked)

What is a sex-influenced trait?

refers to genes on autosomes dominant in 1 sex recessive in the other

What is sex limited?

refers to genes on autosomes dominant/recessive traits only found in one sex (limited), no matter the genotype in the other sex

What is a genotype?

set of alleles possessed by an individual organism

What is a locus?

specific place on a chromosome occupied by an allele

What is a phenotype or trait?

the appearance or manifestation of a characteristic

Which of the statements can be concluded from Gregor Mendel's experiments with pea plants?

two recessive alleles are necessary for a recessive phenotype; The inheritance of alleles of one gene does not affect the inheritance of alleles of another gene

What is binomial?

use to combine probabilities across many events in any order

What is the sum rule?

use to combine probabilities across mutually exclusive events

What is the Chi-square test?

use to test whether observed inheritance patterns follow theoretical expectations (based on Mendel's rules). You should be able to set up, solve, and interpret the result of a Chi square test as applied to genetic systems

What is the product rule?

used to combine probabilities across independent events