Biology 101 Exam #4 Dr. Merk

Who is the father of genetics?

Gregor Mendel

How did he study genetics?

He used pea plants in the first systematic study of inheritance (1860's)

In the pea plans they have both male and female_______?

Gametes

The female pea plant gamete would be the ______?

Ovule

The male pea plant gamete would be the ________?

Pollen

How did Mendel control which plants "mated"?

Mendel removed the male structures and hand-pollinated (fertilized) the plant.

When studying inheritance Mendel focuses on characters in his peas. What are characters?

Characteristics such as seed shape, seed color, and flower color.
The observable physical features.

What are traits when looking at inheritance?

These are a particular form of a character. Such as wrinkled seeds or smooth seeds and purple flowers or white flowers.

How did Mendel start his experiment?

By identifying true-breeding plants for given trait. Example: If two true-breeding plants with purple flowers are crossed, they will always produce only purple offspring.

What was the second step within Mendel's experiment?

he then crossed two true-breeding plants with different forms of the trait. Example: i.e. purple flowers x white flowers.

When you cross two true breeding plants with different forms of the trait this is what generation?

P Generation (true breeding parents)

The offspring of the Parental cross was call the _____________?

F1 Generation

F1 generation refers to the what?

First filial generation and a filial refers to the offspring.

When mendel crossed members of the F1 generation he got the ___________?

F2 Generation

What is a hybrid?

an individual produced by crossing parents with different traits. Example: smooth seed with wrinkled seed

When Mendel crossed the F1 individuals with each other, he was preforming a ____________?

Monohybrid Cross

Mendel repeated monohybrid crosses for each of the ____________?

7 characters he looked at.

The trait that showed up in all F1 plants is called the______________?

Dominant trait

The trait that seemed to disappear is the __________ trait.

Recessive

DNA is stored in the cell nucleus, in multiple individual strands called _______________.

Chromosomes

Each chromosome contains unique "recipes" for proteins called ___________.

Genes

A __________ is the section of DNA on a chromosome that contains the information for making a specific protein.

Gene

We have two of each chromosomes containing the same gene, but the version of the gene may be different. These are called ________________.

Homologous pairs

A version of a gene is called an ________.

Allele

An individual with 2 copies of the same allele in _________.

Homozygous

A plant with one copy of each allele is ___________.

Heterozygous

An individual's __________ is the outward appearance.

Phenotype

The phenotype is determined by the ______________.

Genotype

The dominant allele is denoted with a _____________.

Capital letter

The recessive allele is denoted by a _________.

lower case letters

How are alleles passed on to offspring?

First they must be sorted into gametes.

Special reproductive cells that only have half as many chromosomes as a normal cell is a __________.

Gametes

The sorting process of alleles into gametes take place during ___________.

Meiosis

Mendel's law of segregation allows for us to do what?

Predict the possible allele in gametes.

Once we know the gametes the parents can produce we can use a _______________________ to predict the genotypes of the offspring.

Punnett Square

How do genes determine phenotype?

by coding for proteins with a particular function.

The allele that produces a functional protein is _____________.

Dominant

The allele that often encodes a protein that is not functional is _____________.

Recessive

When tracking inheritance of specific allele in humans it is helpful to look at ____________.

Pedigrees

Family trees that show the occurence of certain traits in several generations is a _____________.

Pedigree

What are some examples of autosomal dominant genetic disorders?

Achondroplasia, Polydactyly, and huntington's disease.

Inheritance pattern of a dominant trait

Anyone who carries even one copy of the allele will show the trait/condition. About half the offspring of an affected parent will show the trait.

Inheritance patterns of a recessive trait.

Affected people (aa) can have two parents that are not affected (Aa). Meaning the trait can skip generations.

Examples of autosomal recessive genetic disorders

Cystic fibrosis, sickle cell anemia, and Tay Sach disease.

Some traits are influenced by the environment these are ________________.

Human height, nutrition, and diseases

Some human traits depend on multiple genes these are __________.

Hair, skin, and eye color.

New alleles arise by _____________.

Mutation

A ____________ is a heritable change in the DNA sequence.

Mutation

Defined as "change in the genetic composition of populations over time"

Evolution

The ________ record shows us how plants and animals have changed (evolved)over time.

Fossil

We can observe evolution of viruses and bacteria in a matter of months/years. Examples: _______________

Antibiotic resistance, new strains.

Attempts to explain how these changes occur, and which specific changes have occured in the past.

Evolutionary Theory

Who is the father of evolution?

Charles Darwin

What did Darwin see on the Galapagos Islands?

Similar species on the mainland , yet not the same. Seemed to "fit"the island environment better than the original mainland versions.

What did Darwin see in regard to fossils?

He found fossils that resembled present-day animals in that region.

Darwin developed a theory explaining evolutionary change. Changes in species over time are due to _____________.

Natural Selection

Differential survival and reproduction based on their traits. Individuals with "better" traits leave more offspring, so those traits become more common in the population over time.

Natural Selection

The environment determines which traits are ________.

Adaptive

Who is Charles Lyell?

Geologist who suggested Earth in MUCH older than 6,000 years. Paved the way for models of gradual change in geologic formations.

Who is Thomas Malthus?

Human populations increase faster than resources. At some point, resources become scarce.

Darwin knew that humans could select for certain traits in animals and plants by selective breeding. Allowing only individuals with specific traits to reproduce increases these traits in the population. This is ____________________.

Artificial Selection

If these traits are ____________ they will increase in population over time.

Heritable

The sum of all alleles in the whole population constitutes that population's ________________.

Gene pool.

More diversity =

More traits to choose (select) from.

For any given allele, the __________ is how often that allele occurs out of all possible alleles for the trait.

Allele Frequency

Anytime the allele frequency changes for a gene is altered what takes place?

Evolution has occurred

Changes from one generation to the next are often very minor/ not noticable. This is _________________.

Microevolution

Over many generations, small changes add up to change the population as a whole. This is ___________________.

Macroevolution

What are the 5 agents of evolutionary change?

1) mutations
2) natural selection
3) gene flow
4) genetic drift
5) sexual selection

What is a neutral mutation?

Mutations that do not affect the organism's chances of survival or reproduction.

What is a harmful mutation?

These mutations put the organism at a disadvantage.

Helpful mutations confer an ____________.

Adaptive Trait

What are environmental factors include in natural selection?

Climate, Nonliving surroundings, and other species in the environment.

___________ refers to the movement of alleles between different populations.

Gene flow

What two things affect gene flow?

Migration of gametes, and individuals.

Sometimes, allele frequencies are altered due to chance. These random changes in allele frequency are referred to as ___________.

Genetic Drift

What is especially influential in small populations?

Genetic Drift

A _____________ refers to a drastic reduction in population size by a random event.

Population Bottleneck

When a few individuals leave a population and start a new population elsewhere reducing the diversity in the new population.

Founder Effect

An adaptive trait increases an individual's chances of _________ and __________.

Survival and reproduction

_____________ refers to selection for traits that help an individual to mate and reproduce.

Sexual Selection

What are the two categories of traits of sexual selection?

Traits that help males compete for females an traits that make males more attractive to females.

In species where males compete for females, sexual selection favors traits that _____________________.

Help males win the competition

In species where females choose a mate, sexual selection favores ____________.

Whatever traits the female likes sometimes quite unusual and hot helpful to the male's survival.

A(n) _____________ trait is helpful for survival and reproduction in a given environment.

Adaptive

A population with lots of _____________ is better able to adapt to changing environmental conditions.

Genetic Diversity

When Darwin observed the different populations of finches in the Galapagos islands, he noticed that their beak shape was well adapted to their __________________.

Food Source

Whether or not a new trait is adaptive in a population depends on.....

The environment in which the population lives.

The sum of all the alleles in a population is called that population's ______________.

Gene Pool

Mutations that produce a new trait

Increases genetic diversity

Gene flow In which new individuals join a population ....

Increases genetic diversity

Genetic drift in which a random sample of individuals is lost from the population.

Decreases genetic diversity

NAtural selection......

Increases adaptive traits in the population across generations.

Genetic drift has the greatest effect on _____________ populations.

Small

Endemic Disease

Are always present in population.
Ex. Common colds, Flu, Stomach Virus, Strep

Epidemic Diseases

Cause infrequent, large outbreaks

What is a pandemic?

Epidemics that span multiple continents.

In early large scale epidemics transmission is promoted by?

Higher population density and unsanitary conditions.

What were the three examples of severe outbreaks?

Bubonic plague, smallpox, and syphilis

What organism caused the bubonic plague?

Yersinia Pestis