Genetics

Two guinea pigs, that are heterozygous for brown fur (Bb) and short fur (Ss) are crossed. What is the probability the offspring will the homozygous dominant for fur color and fur length?

1/4

A mother and father both have AB blood types. What is the probability that their children will have a blood type of A?

25%

BB=black, WW=white, BW=black & white. Listed are the traits for feather color in chickens where the alleles B & W are codominant. A heterozygous chicken has both black and white feathers. If two heterozygous chickens are crossed, what percentage of their offspring will be all white?

25%

A normal human diploid zygote contains

46 chromosomes.

The following lists the traits for hair type in humans where allele C exhibits incomplete dominance over allele C'. CC=curly, C'C' =straight, CC'=wavy. A person who is heterozygous for hair type will have a phenotype of wavy hair. If one parent has wavy hair and the other parent has curly hair, what percentage of their children will have wavy hair?

50%

an example of a trait that is determined by multiple alleles is?

ABO blood groups

Why is colorblindness more common in males than females?

The allele for colorblindness is located on the X chromosome, and since males only have one X chromosome, therefore only have one color gene; Females have 2 X chromosomes, therefore if one doesn't work then the other can take over with that trait.

homologous

a set of chromosomes that has a corresponding chromosome in the male parent as well as the female parent.

selective breeding

allowing only those animals with wanted characteristics to produce he next generation; this process takes advantage of naturally occurring genetic variations, to pass wanted traits on to the next generation of organisms.

DNA fingerprinting

analyzes sections of DNA that may have little or no function but that vary widely from one individual to another.

When a red horse (RR) is crossed with a white horse (WW), the offspring are all roan (RW). How is this explained?

codominance

hybridization

crossing dissimilar individuals to bring together the best of both organisms.

sex chromosomes

determine gender of a baby, females have two copies of XX chromosomes and males have XY.

gene mapping

discovered by Sturtevant while he was working in Morgan's lab. Is a location of where each gene appears on a chromosome.

polyploid plants

drugs that prevent the separation of chromosomes during meiosis, useful to create bigger better plants.

A normal human female has the following sex chromosomes

has two XX chromosomes.

heterozygous

having two different alleles for a trait.

homozygous

having two of the same alleles for a trait, either both dominant or both recessive.

A white rabbit whose parents are both white produces only gray offspring when mated with a gray rabbit. What is the MOST likely genotype of the white rabbit regarding coat color?

homoqygous dominant

nondisjunction

if nondisjunction occurs during meiosis, gametes with an abnormal number of chromosomes may result, leading to a disorder of chromosome numbers.

A red-flowering plant is crossed with a white-flowering plant, and only pink-flowering plants are produced. Which of he following explains this patter of inheritance?

incomplete dominance.

pedigree

is a diagram used by geneticists to chart a trait from one generation to another.

gene

is a factor or factors that are passed from parent to offspring.

sex-linked gene

is a gene located on a sex chromosome.

genetic marker

is a gene that makes it possible to distinguish bacteria that carry the plasmid from those that don't.

sickle cell anemia

is a genetic disease caused by a co-dominant gene.

clone

is a member of a population of genetically identical cells produced from a single cell.

Law of Independent Assortment

is a natural law that explains how traits are inherited independently of other traits. Means that inheriting one trait has no effect on inheriting another trait.

meiosis

is a process in which the number of chromosomes per cell is cut in half through the separation of homologous chromosomes in a diploid cell.

trait

is a specific characteristic, such as seed color or plant height, of an individual.

huntington's disease

is caused by a dominant allele for a protein found in brain cells.

tetrad

is formed when chromosomes pair off, happens during crossing-over.

Dihybrid cross

is studying two traits crossed from parent organisms.

DNA microarray

is technology to study hundreds or even thousands of genes at once to understand their activity levels, is a glass slide or silicon chip to which spots of single-stranded DNA have been tightly attached.

biotechnology

is the application of a technological process, invention, or method to living organisms, to introduce mutations, which are the ultimate source of biological diversity.

inbreeding

is the continued breeding of individuals with similar characteristics.

allele

is the different forms of a gene.

genome

is the full set of genetic information that an organism carries in its DNA.

recombinant DNA

is the joining together of DNA from two or more sources, makes it possible to change the genetic composition of living organisms.

probability

is the likelihood that a particular event will occur.

hybrid

is the offspring of crosses between parents with different traits.

gene therapy

is the process of changing a gene to treat a medical disease or disorder.

genetics

is the study of heredity

gene linkage

is when alleles of different genes tend to be inherited together from one generation to the next when those genes are located on the same chromosome.

fertilization

is when male and female reproductive cells join to create a new organism

codominance

is when the phenotypes produced by both alleles is clearly expressed; is having two or more alleles that are equally dominant for a trait so that both traits are expresses; for example, roan cattle have both red hair and white hair (not pink)

incomplete dominance

is where one allele is not completely dominant over another allele. is having alleles that do not have complete dominance so the resulting trait is a mix of two alternate traits; for example, red snapdragons crossed with white snapdragons produce pink snapdragons.

Two rabbits with brown eyes have one out of four offspring with pink eyes. Which of the following is MOST likely concerning pink eye color?

it is recessive.

cystic fibrosis

known as CF for short, cystic fibrosis is most common among people of European ancestry, is caused by a genetic change; causes the protein to fold improperly, causing tissues throughout the body to malfunction.

polymerase chain reaction

making many copies of genes; the first step in using the polymerase chain reaction method is to copy a gene is to heat a piece of DNA, which separates its two strands; then as the DNA cools, primers bind to the single strands; next, DNA polymerase starts copying the region between the primers; these copies can serve as templates to make still more copies.

multiple alleles

many genes exist in several different forms and are therefore said to have multiple alleles.

Where are most sex-linked genes located?

on the X chromosome

A normal male has the following sex chromosomes

one X and one Y chromosome.

transgenic

organisms can be produced by the insertion of recombinant DNA, into the genome of a host organism.

a chart that traces the inheritance of a trait in a family is called a

pedigree

bioinformatics

root word, informatics, refers to the creation, development, and operation of databases & other computing tools to collect, organize, and interpret data.

Vestigial

same structure, does not work normally.

segregation

separation of alleles during meiosis.

gametes

sex cells.

karyotype

shows the complete diploid set of chromosomes grouped together in pairs, arranged in order of decreasing size.

pedegree

shows the presence of absence of a trait according to the relationships between parents, siblings, and offspring.

independent assortment

states that genes for different traits can segregate independently during the formation of gametes.

principle of dominance

states that some alleles are dominant and others are recessive.

Monohybrid cross

studying one trait crossed from parent organisms.

According to the law of independent assortment, the inheritance of alleles for one trait is not affected by the inheritance of alleles for different trait. In what case can there be an exception to this rule?

the genes are on the same chromosome.

genotype

the genetic makeup of a trait.

A mother with a blood type of A has a son with a blood type of B. Which of the following CANNOT be true?

the mother is homozygous for blood type.

9:3:3:1

the phenotypic ration for all heterozygous dihybrid crosses.

phenotype

the physical appearance of a trait, what can be seen.

forensics

the scientific study of crime scene evidence

what is the difference between autosomes and sex chromosomes?

the sex chromosomes, X & Y, determine an individual's sex; the remaining 22 pairs of chromosomes are autosomal.

diploid

the whole set of chromosomes, is achieved after fertilization.

restriction enzymes

these highly specific substances cut even the largest DNA molecule into precise pieces, called restriction fragments, that are several hundred bases in length.

zygote

this is the name that is given to a fertilized egg.

gel electrophoresis

to separate and analyze the differently sized fragments of DNA.

polygenic traits

traits controlled by two or more genes.

punnett square

uses mathematical probability to help predict the genotype and phenotype combinations in genetic crosses.

Human Genome Project

was a 13 year, international effort with the main goals of sequencing all 3 billion base pairs of human DNA and identifying all human genes.

haploid

when a cell contains only a single set of chromosomes, Half the number of normal chromosomes for that individual. Hasn't been fertilized yet.