Biology Final Exam

What is a Genome?

Is all of an organism's genetic material.

What is a Phenotype?

Refers to the physical characteristics of a trait.

What is a Dominant Allele?

Is the allele that is expressed when two different alleles are present.

What is a Gene?

Is a section of DNA that encodes for a functional product.

What does Heterozygous mean?

Means that the two alleles for a gene are different.

What does Homozygous mean?

Means that the two alleles for a gene are the same.

What is an Allele?

Is an alternative form of a gene.

What is a Recessive Allele?

Is the allele that is expressed only when two of the same alleles are present.

What is a Trait?

Is a distinguishing characteristic that is inherited.

What is a Genotype?

Refers to the genes for a trait.

In achondroplasia, what are the genotypes and phenotypes for Homozygous dominant?

DD - Dwarf / Short.

In achondroplasia, what are the genotypes and phenotypes for Heterozygous?

Dd - Dwarf / Short.

In achondroplasia, what are the genotypes and phenotypes for Homozygous recessive?

dd - Normal.

What is the Cell Cycle?

Is the regular pattern of growth, DNA duplication, and cell division that occurs in eukaryotic cells.

What is Chromatin?

Is the term that refers to DNA that is loosely wrapped around histone proteins during interphase.

What is a Centromere?

Is the region that holds the two sister chromatids together in a condensed chromosome.

What is Telophase?

Is the process that divides the cell cytoplasm.

What is a Cleavage furrow?

Is the structure that forms between two nuclei in animal cells that are undergoing cytokinesis.

What happens in Anaphase?

A complete set of identical chromosomes is positioned at opposite sides of the cell.

What is a Chromosome?

Is the term that refers to DNA that is tightly wrapped around histone proteins during mitosis.

What is Cytokinesis?

The sister chromatids separate from each other.

What is a Cell plate?

Is the structure that forms between two nuclei in plant cells that are undergoing cytokinesis.

What are Telomeres?

The ends of DNA molecules form structures called telomeres.

What is a Chromatid?

One half of a duplicated chromosome.

What happens in Metaphase?

The chromosomes align along the middle of the cell.

What happens during Prophase?

Chromatin condenses into tightly coiled chromosomes.

What is Histone?

Is the type of protein that DNA wraps around to form chromatin.

What happens during Interphase?

The cell grows and copies its DNA in preparation for division.

What is a Sex Chromosome?

Is a chromosome that determines the sex of an organism.

What is an Autosome?

Any chromosome (1 through 22) that is not involved in determining the sex of an organism.

What is Amniocentesis?

Is the procedure in which fetal cells are obtained for genetic analysis.

What are Homologous Chromosomes?

Are two chromosomes that have the same size, appearance, and genes.

What does Haploid mean?

Means a cell has one copy of each chromosome.

What is a Zygote?

Is the cell that forms when a sperm fertilizes an egg.

What is Crossing-over?

Is the exchange of chromosome segments between homologous chromosomes during meiosis.

What is a Karyotype?

Is an image of the chromosomes in a cell, arranged as homologous pairs based on size, shape, and banding pattern.

What is Nondisjunction?

Describes the failure of homologous chromosomes or sister chromatids to separate correctly during meiosis.

What is Fertilization?

Occurs when the nucleus of an egg and sperm fuse to form one nucleus.

What is Gametogenesis?

Involves the fusion of two gametes and results in offspring that are a genetic mixture of both parents.

What does Diploid mean?

Means a cell has two copies of each chromosome.

What is Meiosis I?

Is the process by which offspring are produced from a single parent.

What are Gametes?

Are the sex cells - eggs in the female and sperm cells in the male.

What is Trisomy?

Is when a cell receives three copies of a chromosome.

What are Somatic cells?

Also called body cells, make up the tissues and organs of an organism.

What is gametogenesis?

Is the production of gametes.

What is a Gene?

Is a segment of DNA that codes for a protein.

How many chromosomes are present in the cell during prophase I?

2.

How many of each size chromosome are present in the cell during prophase I?

2.

Is the cell in prophase I diploid or haploid?

Diploid.

How many chromosomes are present in each cell after anaphase I?

1.

How many of each size chromosome are present in each cell during prophase II?

1.

Nondisjunction

When the mitotic spindle doesn’t form during anaphase

Is the cell in prophase II diploid or haploid?

Haploid.

During which phase do homologous chromosomes separate?

Anaphase I.

During which phase do sister chromatids separate?

Anaphase II.

During which phases does nondisjunction occur in meiosis?

Anaphase I and Anaphase II.

During which phase does crossing over occur in meiosis?

Prophase I.

What is Equilibrium?

Describes when a reaction takes place at an equal rate in both directions.

What are Endergonic Reactions?

Is a reaction in which the bond energy of the products is greater than the bond energy of the reactants.

What is Activation Energy?

Is the amount of energy that must be absorbed in order to start a chemical reaction.

What is a Reactant?

Is the substance that is changed during a chemical reaction.

What is a Chemical Reaction?

Changes substances into different substances by breaking and forming chemical bonds.

What is a Product?

Is the substance that is made during a chemical reaction.

What is an Exergonic Reaction?

Is a reaction in which the bond energy of the products is less than the bond energy of the reactants.

What is an Active Site?

Is the site on an enzyme that attaches to the substrate.

What does Denature mean in relation to enzymes?

Refers to when a protein's shape is changed due to changes in environmental conditions.

What is a Catalyst?

Is any substance that decreases the activation energy and increases the rate of a chemical reaction.

What is an Enzyme?

Is a biological catalyst for chemical reactions that occurs in cells.

What is a Substrate?

Is the reactant that interacts with an enzyme.

What type of inheritance is displayed when a certain species of betta fish are green, blue, or royal blue (a blending of green and blue)?

Incomplete dominance.

What type of inheritance is displayed when polydactyly (having six fingers per hand) is dominant over the trait for five fingers?

Simple dominance.

What type of inheritance is displayed by color blindness?

Sex-linked.

What type of inheritance is displayed by human blood type?

Codominance (for A and B alleles) and Simple dominance (for A and B over O).

What is Artificial Selection?

An example would be crops grown for specific traits.

What is Genetic Drift?

Occurs when a random chance event changes the allele frequency of a population.

What concept do Darwin's finches exemplify?

Adaptive Radiation, since they all have different beak shapes, yet share a common ancestor.

What did Darwin collect on his voyage that looked similar to modern day armadillos?

Fossils.

What is a Gene Pool?

Is all of the different alleles for a population.

What is Natural Selection?

Is the process in which organisms who are better fit for an environment will survive and reproduce.

What is Sympatric Speciation?

Occurs even when a population is living in the same area (e.g., polyploidy).

What is Biogeography?

One piece of evidence for evolution which looks at where various species live.

Founder effect

Smaller groups form out of one large group and create a new population in a new location

Bottleneck effect

Large population experiences drastic change reducing genetic diversity

What is Gene Flow?

Occurs when new allele enters into a population from another.

What is Allopatric Speciation?

Event occurs when geographical barriers separate a population.

What is Molecular Homology?

An example would be the forearms of humans, whales, cats, and bats.

What are examples of Prezygotic barriers?

Habitat, Temporal, Behavioral, Gametic, Mechanical isolation are all examples of reproductive barriers.

What is Antibiotic Resistance?

If you have an ear infection that will not go away with one drug that medication has likely evolved to have it.

What are Postzygotic barriers?

Reproductive barriers often occur in animals that are hybrids (e.g., ligers).

What is Anatomical Homology?

When DNA is similar between two species they have it.

What is Speciation?

Event occurs when one species splits into two or more.

What is a Biotic factor?

Living components within an ecosystem (plants, animals, fungi, etc.).

What is Carrying Capacity?

The maximum population size that a particular environment can sustain.

What is Exponential growth?

Idealized population growth where there is unlimited growth.

What is Mutualism?

A symbiotic relationship where both organisms benefit.

What are Ecological disturbances?

Events such as storms, fires, floods, droughts, and human activity that damage biological communities and alter resource availability.

What is Ecology?

The study of interactions between organisms and their environment.

What is Competition?

A type of species relationship when ecological niche space is overlapping, making organisms defend limited shared resources. Both organisms are harmed.

What is Predation?

A type of interspecies relationship where one organism kills and eats another.

What is a Biome?

A geographical region characterized by the climate and ecological associations within it.