Biology Finals

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Darwin's Theory of Evolution

Those individuals that are best adapted to the environment will survive and reproduce

those traits that help them

become more common in a species and maladaptive traits die out. This is called natural Selection.

Lamarck's Theory of Evolution

If an organism changes during life in order to adapt to its environment

Mitosis

part of eukaryotic cell division during which the cell nucleus divides

Meiosis

Cell division that produces reproductive cells in sexually reproducing organisms (sexual reproduction and production of gametes)

Mitosis stages (PMAT)

prophase

Prophase

spindle forms

Metaphase

Chromosomes line up in the middle of the cell

Anaphase

Phase of mitosis in which the chromosomes separate and move to opposite ends of the cell

Telophase

After the chromosome seperates

Cytokinesis

division of the cytoplasm

Interphase

Cell grows

consists of G1

S

The stages of meiosis in the correct sequence

Prophase I

What is produced at the end of meiosis?

4 haploid daughter cells

What is produced at the end of mitosis?

2 identical daughter cells

What does transcription start with and end with?

DNA to mRNA

What holds sister chromatids together?

centromere

What is a replication fork?

Point in a DNA molecule where the two strands separate during replication.

What does translation start with and end with?

mRNA to protein

Protein synthesis

the formation of proteins by using information contained in DNA and carried by mRNA

sister chromatids

Identical copies of a chromosome

sister chromatids

full sets of these are created during the S subphase of interphase.

Spindle

fanlike microtubule structure that helps separate the chromosomes during mitosis

4 phases of cell cycle

G1

Why might a cell undergo mitosis?

1. Growth
2. Remove unresponsive cells

Why is replication needed before cell division?

The new cell needs DNA that is identical to the original

What does it mean when the cell is haploid?

It has only one copy of each chromosome (egg and sperm) (1n)

What does it mean when the cell is diploid?

It contains two sets of chromosomes (1 from mom and 1 from dad) (2n)

Crossing over

Process in which homologous chromosomes exchange portions of their chromatids during meiosis.

Genetic Variation

Differences among individuals in the composition of their genes or other DNA segments

Gamete

sex cell

Fertilization

Process in sexual reproduction in which male and female reproductive cells join to form a new cell

Zygote

fertilized egg

Why may crossing over result in an increase in genetic variation?

Mom's and dad's chromosomes exchange genetic information

What is the genetic material of a virus?

DNA or RNA

How do cells reproduce?

mitosis

How do viruses reproduce?

Viruses can reproduce only by infecting living cells

Structure of a virus

All viruses have 2 basic parts: a protein coat that protects the virus and an inner core (where there is Genetic Material). The proteins on a virus are what allows them to get inside the cell after matching with the membrane proteins on the cells membrane envelope.

Why are viruses not considered living?

They cannot reproduce by themselves and do not have all characteristics of life

The double coiled shape of DNA is called the...

Double-Helix

A segment of DNA that codes for a protein is known as the...

gene

Base pairing rules for DNA

A-T
G-C

Base pairing rules for RNA

A-U
G-C

What nucleic acids are involved in replication?

DNA

What nucleic acids are involved in transcription?

DNA and RNA

What nucleic acids are involved in translation?

mRNA

Why would a cell need to replicate its DNA?

so when it divides each daughter cell will have the correct amount of DNA

growth

repair

How is DNA different from RNA?

- DNA contains A

Does a mutation in DNA always result in a phenotypic change?

No some mutations do not change the aa sequence - silent mutations

The different forms of a gene are called...

alleles

The physical characteristics of an organism is known as the...

phenotype

Homologous

term used to refer to chromosomes that each have a corresponding chromosome from the opposite-sex parent

When the genotype is heterozygous

the two alleles are...

When the genotype is homozygous

the two alleles are...

This kind of allele has its trait show up in the organism when the allele is present

dominant allele

This kind of allele is not allowed to be presented when the dominant allele is present

recessive allele

This type of dominance occurs when phenotypes of the heterozygote and dominant homozygote are identical

complete dominance

This type of dominance occurs when one allele is not fully dominant over another

Incomplete dominance

This type of dominance occurs when both alleles are expressed and each genotype has its own phenotype

Codominance

What does sex-linked mean?

The alleles that code for them are located on a sex chromosome (X)

This type of trait is controlled by two or more genes

Polygenic

A cross between a purebred animal with red hairs and a purebred animal with white hairs produces an animal that has both red hairs and white hairs. What type of inheritance pattern is involved?

Codominance

In a cross between individuals of a species of tropical fish

all of the male offspring have long tail fins

Suppose you mate a black rooster with a white hen. The feathers of all the offspring are grey and white. What is the inheritance pattern being expressed?

Incomplete dominance

In chimpanzees

straight fingers are dominant to bent fingers. Cross a heterozygous straight fingered chimpanzee with x bent fingered chimpanzee. List the percentages of all possible genotypes and phenotypes of their offspring.

In humans

tongue rolling is a dominant trait

those with the recessive condition cannot roll their tongues. Bob can roll his tongue

but his mother could not. He is married to Sally

In snapdragons

flower color is controlled by incomplete dominance. The two alleles are red (R) and white (W). The heterozygous genotype is expressed as pink. A pink-flowered plant is crossed with a white-flowered plant. List the percentages of all possible genotypes and phenotypes of their offspring.

This law states that alleles of a gene are separated from each other during meiosis.

Law of Segregation

This law states that gene pairs are transmitted independently of each other during gamete formation.

Law of Independent Assortment

The process by which different kinds of living organisms are thought to have developed and diversified from earlier forms during the history of the earth.

evolution

The process whereby organisms better adapted to their environment tend to survive and produce more offspring

Natural Selection

A trait that helps an organism survive and reproduce is called...

adaptation

Any difference between individuals of the same species is known as...

Variation

This is the general ability of an organism to survive and reproduce in its environment...

Fitness

A trace of an ancient organism that has been preserved in rock is known as...

Fossil

Structures in different species that are similar because of common ancestry but perform different functions are called...

Homologous Structures

This occurs when the members of two populations cannot interbreed and produce fertile offspring

reproductive isolation

This occurs when populations are physically separated and therefore never mate

geographic isolation

The formation of a new species is called...

speciation

The ending of a species is called...

extinction

Name three ways in which natural selection can disrupt the distribution of phenotypes among individuals within a species.

a. directional selection
b .stabilizing selection
c. disruptive selection

This selection favors one extreme

Directional selection

This selection favors the average

Stabilizing selection

This selection favors both extremes

Disruptive selection

Variation among all living organisms is called...

Biodiversity

A series of steps in which organisms transfer energy by eating and being eaten is known as a...

Food chain

A community of organisms where there are several interrelated food chains is called a...

Food web

An organism that makes its own food is called a...

producer

An organism that obtains energy by feeding on other organisms is called a...

consumer

An organism that eats producers is called a...

Primary consumer

An organism that eats primary consumers is called a...

Secondary consumer

An organism that eats secondary consumers is called a...

Tertiary consumer

An organism that breaks down wastes and dead organisms is known as a...

decomposer

Trophic Levels of a Food chain

producer

A pyramid representing the steps of energy (who consumes who) is called...

Energy pyramid

An interaction in which one organism kills another for food is called...

predation

A relationship between two organisms of different species where one benefits and the other is harmed is called...

parasitism