Heredity and Evolution

Terms in this set (35)

Asexual Reproduction
Method of reproduction used by organisms that are able to clone themselves to produce an exact copy of the parent. Types include binary fission, fragmentation, parthenogenesis and budding.
Sexual Reproduction
Method of reproduction used by organisms of the same species who mate to produce offspring resulting in genetic variation. Types include internal fertilization, external fertilization and pollination.
DNA
The genetic makeup of all living organisms housed in nucleus of the cell within the chromosomes. Determines all structures and functions of the living organisms.
Chromosome
Thread-like pieces in the nucleus of the cell carrying the DNA. Humans have 23 pairs of chromosomes.
Gene
A specific sequence of molecules in the DNA of an organisms which codes for a certain trait.
Mutation
A problem occurring during replication of the DNA or during growth of an organism. May result in helpful, harmful, or neutral changes to the DNA. Is the driving force of evolution.
Genetics
A branch of biology specific to the study of inheritance.
Heredity
the sum of the characteristics and potentialities genetically derived from one's ancestors
Hybrid
the offspring of two different species.
Punnett Square
A model used to determine the probability of genotype and phenotype traits of offspring given the genotype of two parents.
Allele
a form of a gene occuring in a given location in the DNA
Dominant
A trait that shows up even if the other allele is recessive.
Recessive
A trait that is expressed only in the homozygous recessive inheritance type.
Genotype
the genetic makeup of an individual usually expressed in letters using capital and lowercase representations
Phenotype
the physical characteristics coded by the genotype
Homozygous
two of the same alleles
Heterozygous
two different alleles
Genetic Engineering
the group of applied techniques of genetics and biotechnology used to cut up and join together genetic material and especially DNA from one or more species of organism and to introduce the result into an organism in order to change one or more of its characteristics
Sex-Linked
a trait inherited on an X or Y chromosomes (the sex chromosomes)
Incomplete Dominance
the property of being expressed or inherited as a semidominant gene or trait where neither allele is dominant or recessive, instead the phenotype appears like a mix of the two.
Species
a category of biological classification ranking immediately below the genus or subgenus, comprising related organisms or populations potentially capable of interbreeding
Natural Selection
a natural process that results in the survival and reproductive success of individuals or groups best adjusted to their environment and that leads to the perpetuation of genetic qualities best suited to that particular environment
Adaptation
modification of an organism or its parts that makes it more fit for existence under the conditions of its environment : a heritable physical or behavioral trait that serves a specific function and improves an organism's fitness or survival
Evolution
descent with modification from preexisting species : cumulative inherited change in a population of organisms through time leading to the appearance of new forms : the process by which new species or populations of living things develop from preexisting forms through successive generations
Compare and contrast sexual and asexual reproduction.
Sexual reproduction is a form of mating which needs two parents- the male with the sperm and the female with the eggs. The sperm and egg meet for fertilization. This can happen internally such as in mammals or externally such as in fish. This also occurs during pollination of flowers. The offspring are genetically different than the parents created variation among the species and therefore the species is more equipped to change over time and survive. Asexual reproduction is a form of reproduction when only one parent is needed. This can happen via budding, parthenogenesis, fragmentation or binary fission. The resulting offspring is an exact clone of the parent meaning the DNA is exactly the same and there is no genetic variation.
Which method of reproduction is more effective at creating diversity over time?
Sexual Reproduction is more effective at creating diversity over time.
Explain how DNA affects how an organism looks and or behaves.
DNA is a genetic code within the nucleus of all cells. The code codes for genes and genes code for traits. Traits determine how an organism looks and behaves.
Explain how mutations affect an organism's looks or behavior and if this is a good or a bad thing.
Mutations alter the genetic code. Depending on the gene is is changing this could be helpful, harmful or neutral. Depending on how large of a mutation it is it can also be helpful, harmful or neutral.
What is the difference between a gene and an allele?
An allele is a different form of a gene whereas a gene is a code or specific sequence of DNA. One bunny can have an allele for short hair and another can have an allele for long hair but they are from the same gene sequence just two different versions of that gene.
Explain why one parent has the potential to pass on one of two different alleles for one gene to its offspring.
One parent has the potential to pass one of two different alleles for one gene to its offspring if the parent is heterozygous genotype of the gene. This can be modeled in a Punnett Square.
Explain why offspring tend to have a mixture of the traits of both parents and how alleles determine traits.
Offspring tend to have a mixture of the traits of both parents because they receive one allele from each parent therefore this is a mix. Alleles determine traits by their pattern of inheritance. If a trait is dominant then it will show in the phenotype. For example if the trait is recessive then that trait will show in the genotype if there are two recessive alleles making up that genotype.
Explain how two parents who do not have a recessive genetic disease can pass that disease onto their offspring.
Two parents who do not have a recessive genetic disease can pass that disease onto their offspring if the disease is sex linked and one of the parents is a carrier for the gene. Examples where this occurs includes color-blindness and sickle-cell anemia both of which are X-linked disorders.
Explain how the fossil record shows evidence of evolution.
The fossil record shows evidence of evolution because it shows a progression of an organism from simple to complex over an extended period of time.
Explain how homologous structures show evidence of evolution.
Homologous structures demonstrate the similarity in the structure or structures of an organism such as bat wing and dolphin flippers or human arms and cat legs, linking the species with a common ancestor.
Explain how comparing embryos shows evidence of evolution.
There are shared traits between embryos of different organisms, showing that they have a common ancestor. For example, fish embryos and human embryos both have gill slits. In fish they develop into gills, but in humans they disappear before birth.
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