bio chapter 7

If two people have type ab blood what types of blood might there children have?

A,b, or ab .. Only a recessive a or recessive b or an O can have an O offspring

Give an example of a phenotype with an epistatic gene

Albinism

How many genese determine hair and eye color,skin color?

At least 3 for eye, 4 for skin, 5 for mouse fur

How do genes on autosomes affect phenotype?

Because ther are two copies of each gene on autosomes- one on each homoloagous chromosome, and each copy can influence pheontype

How are genotypes and pheontypes traced to determine if both males and females carry recessive alleles?

By use of a pedigree chart of phenotypes of parents, boxes are female, circles are male, shaded means dominant, partially shaded means heterozygous, white is recessive

What do karyotypes show?

Changes in chromosomes

Where are genes located?

Chromosomes

What are autosomes?

Chromosomes that do not play a direct role in sex determination

A white cat breeds with a orange cat and has kittens with white and orange splotches. This is an example of

Codominance

What is one disorder that can be identified using karyotypes?

Downs syndroms

A gene that interferes with the expression of another gene is called____

Epistatic

What else do scientists use karyotypes for?

Estimate distances between genes on a chromosome

What are sex linked genes?

Genes located on x or y chromosomes

Each pair of chromosomes contain the same ------- but different -------

Genes..alleles

Morgan concluded tha chromosomes must exchange what thpe of genes during meiosis?

Homologous genes

What genotype would a person have who dos not show the pheontype for a trait controlled by an autosomal gene?

Homozygous recessive

What is x chromosome inactivation, give an example

In females one of the 2 x chromosomes is randomly turned off, ex calico cats show all three colors

What makes huntingtons disease so fatal?

It is a dominant disorder and doesnt appear until later in life after carrier has had children and passed it on

How is it that a person can inherit a genetic disorder if neither parents appear to have the disease

It is recessive and is either sex linked or parents are heterozygous

How is hemophelia passed down, can bith males and females be symptomatic for this disorder?

It is recessive on x chromosome. A female would have to have both parents with the disorder, a male gets it from his mother on the x chromosome

What is the probability that 2 genes will be inherited together?

It is related to the distance between them, the closer together the most likely

A method for studying human chromosomes which utilizes pictures that have been chemically stained by dyes is called

Karyotypes

How are the loco or locations of genes recorded?

Linkage map

What did morgan conclude after his experiments with fruit flies

Linked genes were on the same chromosome. The chromosomes not the genes assort independently

Who expresses more of the alleles ona gene, males or females

Males because they dont have an extra copy of the x to mask traits

During what tupe of cell division does this occur?

Meisosis

How do multiple allele traits differ from polygenic traits

Multiple allele traits are codominsny like blood type and splotched cats, polygenic traits are one trait produced by two or more genes such as eye color

What information is needed to identify genotypes in pedigree groups formeither widows peaks or color blindness?

Need to know pheonotype of each parent, need to know if trait is recessive or dominant, need to know genotype of each condition

Give an example of incomplete dominance and explain how it coan occur genetically

Neither allele is completely dominant or recessive so traits "blend" example green eyes or pink flowers when jomozygous red and white flowers are crossed.

Is the karytotype method considered effecient?

No

Why must a combination of methods be used when studying human gnentics?

No method is exact and assumptions must be made based on probability and phenotype

Are identical twins always identical, why or why not?

No, environmental factors can influence the pheontype of one twin.

Are linked genes always inherited?

No, it depends on how close they are on the chromosome, the closer, the more likely

If two genes have the same number of map units, do they always have the same physical distance between them?

No, many factors affect gene linkage, so the map units do not always equal physical distance apart

Each pair consists of ----- from each parent

One

Who are the carriers of sex linked disorders, males, females or both?

Only females

What is one map Unit equal to on a location mep?

Ons crossover per each 100 offspring

How are pedigrees and punnet squares different?

Pedigrees record actual genotypes and Phenotypes, Punnet squares arecord probabilities

Interaction of alleles can determine ------

Phenotype

Different alleles produce different ------------

Phenotypes

Traits produced by two or more genes are _________

Polygenetic traits

What causes most genetic disorders

Recessive alleles om autosomes

Shat thpes of traits aree most helpful in understanding human genetics?

Single gene traits

What external forces interact with genes to affect phenotype, give example

Sun, nutrition, drugs and alcohol during pregnancy

How did mendels observations relate to genes on autosomes?

The traits he observed were on autosomes like peas color and texture

Sexually reproducing organisms have --------of each chromosome

Two

What chromosome has the greates influence over phenotype?

X because it contains more genes that affect traits and is longeer than y

Can thie chance of a person inheriting a genetic disorder be predicted?

Yes