Unit 7 Flashcards Part 1

Front 1

Heredity

Back 1

Heredity is the passing on of physical or mental characteristics genetically from one generation to another.

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Offspring

Back 2

Offspring is a person's child or children. // Offspring is the product or result of something.

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Gene

Back 3

A gene is a locus (or region) of DNA that encodes a functional RNA or protein product, and is the molecular unit of heredity. :Glossary. The transmission of genes to an organism's offspring is the basis of the inheritance of traits.

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Genetic trait

Back 4

A trait is a specific characteristic of an organism. Traits can be determined by genes or the environment, or more commonly by interactions between them. The genetic contribution to a trait is called the genotype. The outward expression of the genotype is called the phenotype.

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Allele

Back 5

An allele is a variant form of a gene. Some genes have a variety of different forms, which are located at the same position, or genetic locus, on a chromosome. Humans are called diploid organisms because they have two alleles at each genetic locus, with one allele inherited from each parent.

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Genotype

Back 6

A genotype is an individual's collection of genes. The term also can refer to the two alleles inherited for a particular gene. The genotype is expressed when the information encoded in the genes' DNA is used to make protein and RNA molecules.

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Phenotype

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A phenotype is an individual's observable traits, such as height, eye color, and blood type. The genetic contribution to the phenotype is called the genotype. Some traits are largely determined by the genotype, while other traits are largely determined by environmental factors.

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Dominant

Back 8

To be dominant means to be most important, powerful, or influential. // In genetics, a trait that will appear in the offspring if one of the parents contributes it. Ex. In humans, dark hair is a dominant trait; if one parent contributes a gene for dark hair and the other contributes a gene for light hair, the child will have dark hair.

Front 9

Recessive

Back 9

Recessive is when relating to or denoting heritable characteristics controlled by genes that are expressed in offspring only when inherited from both parents, i.e., when not masked by a dominant characteristic inherited from one parent.

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Homozygous

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Alternative forms of a given gene are called alleles, and they can be dominant or recessive. When an individual has two of the s a m e allele, whether dominant or recessive, they are homozygous.

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Heterozygous

Back 11

Heterozygous means having one each of two different alleles.

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Cross

Back 12

Genetic cross. Similar term(s): crossbreeding. Definition: The deliberate breeding of two different individuals that results in offspring that carry part of the genetic material of each parent. The parent organisms must be genetically compatible and may be from different varieties or closely related species.

Front 13

Monohybrid Punnett Square

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The Punnett square is a diagram that is used to predict an outcome of a particular cross or breeding experiment. It is named after Reginald C. Punnett, who devised the approach. The diagram is used by biologists to determine the probability of an offspring having a particular genotype.

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F1 Generation

Back 14

An F1 hybrid (or filial 1 hybrid) is the first filial generation of offspring of distinctly different parental types. F1 hybrids are used in genetics, and in selective breeding, where it may appear as F1 crossbreed.

Front 15

simple dominance

Back 15

Simple dominance occurs when an inherited trait is coded for by a single gene and that gene has two versions, or alleles: the dominant version and the recessive version. The dominant allele of the gene hides the presence of the recessive allele.

Front 16

incomplete dominance

Back 16

Incomplete dominance refers to a genetic situation in which one allele does not completely dominate another allele, and therefore results in a new phenotype.

Front 17

co-dominance

Back 17

Co-dominance is a relationship between two versions of a gene. Individuals receive one version of a gene, called an allele, from each parent. If the alleles are different, the dominant allele usually will be expressed, while the effect of the other allele, called recessive, is masked.

Front 18

hybrid

Back 18

Hybrid is the offspring of two plants or animals of different species or varieties, such as a mule (a hybrid of a donkey and a horse).