Physical Anthropology Quiz 2 Nancy Garr

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Mitochondria (singular- mitochondrion)

Back 1

Organelles contained within the cytoplasm of eukaryotic cells that convert energy, derived from nutrients, into a form that is used by the cell.

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Ribosomes

Back 2

Organelles located in the cell's cytoplasm that are essential to the manufacture of proteins.

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Centrioles

Back 3

Organelles located in the cell's cytoplasm that help to organize the assembly of microtubules during cell division.

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Chromosomes

Back 4

Nuclear organelles made of DNA and other proteins; in eukaryotic cells they are found only in the nucleus. They are the carries of genetic information in the cell.

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Centromere

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The constricted portion of a chromosome. After replication the duplicated chromosome are joined at the centromere.

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Somatic cells

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Body cells (muscle, brain, blood, or bone cells, for example); basically all cells in the body except reproductive cells (gametes)

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Gametes

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Cells produced through meiosis that carry a haploid set of chromosome to the next generation

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Zygote

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Diploid fertilized egg formed by union of haploid egg and sperm

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Homologous chromosomes

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Matching pairs of chromosomes, one member of the pair is inherited from each parent

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Sex chromosomes

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Chromosomes that determine sex (and some other traits)

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Autosomes

Back 11

All the chromosomes except the pair that determines sex

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Diploid set

Back 12

The full set of 23 homologous pairs of chromosomes (2 or each kind or 46)

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Haploid set

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Set formed when there is only one from each of the homologous pairs of chromosomes (one of each kind or 23)

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Gene

Back 14

Segment of a chromosome. Genes code for all or part of a specific protein (or other functional product).

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Locus/loci

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Fixed position or location of the gene on the chromosome

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Allele

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Alternate form of a gene

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Deoxyribonucleic acid (DNA)

Back 17

Two-stranded molecule made of chains of nucleotides twisted into a double helix

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Molecules

Back 18

Structures made up of two or more atoms. Molecules can combine with other molecules to form more complex structures

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Nucleotide

Back 19

Basic units of the DNA molecule, composed of a sugar, a phosphate, and one of four DNA bases.

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Complementary

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Referring to the fact that DNA forms base pairs in a precise manner. Since adenine and thymine can only bond with each other, they are said to be complementary to each other. Cytosine and guanine are another complementary pair.

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Protein

Back 21

Molecules made of chains of amino acids; they serve a wide variety of functions through their ability to bind to other molecules.

Front 22

Protein synthesis

Back 22

A process, directed by DNA, in which chains of amino acids are assembled into functional protein molecules.

Front 23

Amino acids

Back 23

Small molecules that are the building blocks of proteins

Front 24

Ribonucleic acid (RNA)

Back 24

A molecule similar to DNA, but it is single stranded, with a different sugar, and with uracil replacing thymine. RNA is essential to the production of proteins

Front 25

Messenger RNA (mRNA)

Back 25

A form of RNA that is assembled on a sequence of DNA bases. It carries the DNA code to the ribosomes during protein synthesis.

Front 26

Transfer RNA (tRNA)

Back 26

The type of RNA that binds to specific amino acids and carries them to the ribosome during protein synthesis

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Replicate

Back 27

To duplicate. DNA replication takes place prior to any type of cell division.

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Mitosis

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Cell division that leads to the production of somatic cells

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Meiosis

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Cell division that leads to the production of gametes

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Mutation

Back 30

A change in DNA bases, number, or structure (see point mutation and nondisjunction)

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Nondisjunction

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The failure of homologous chromosomes or chromosome strands to separate during cell division; results in a cell with an abnormal number of chromosomes

Front 32

Point mutation

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A change in the DNA base sequence of a gene that can lead to the production of a new protein

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Genotype

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The actual genetic makeup of an individual; the actual alleles that are present

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Phenotype

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The observable, measurable, physical expression of the genotype as affected by the environment

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Dominant

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An allele that masks the effect of another

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Recessive

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An allele whose expression can be masked by another

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Codominant

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The expression of two alleles in heterozygotes. Because neither allele is dominant or recessive, both influence the phenotype

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Heterozygous

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Having 2 different alleles at a given locus on a pair of homologous chromosomes

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Homozygous

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Having 2 of the same alleles at a given locus on a pair of homologous chromosomes

Front 40

Principle of Segregation

Back 40

Genes (alleles) occur in pairs (because chromosomes occur in pairs). During gamete production, the members of each gene pair separate, so that each gamete contains one member of each pair. During fertilization, the full number of chromosomes is restored, and members of gene or allele pairs are reunited.

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Principle of Independent Assortment

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The distribution of one pair of alleles into gametes does not influence the distribution of another pair. The gene controlling different traits are inherited independently of one another.

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Mendelian or monogenic traits

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Traits that are influenced by alleles at only one locus

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Discrete distribution

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Mendelian or monogenic traits, coded for by one gene, fall into clearly defined categories. For example, each human has either type A, B, AB or O blood.

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Polygenic traits

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Traits that are influenced by genes at two or more loci.

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Continuous distribution

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Polygenic traits, coded for by two or more genes, show continuous variation, from one extreme to another. Traits are measured in units on a scale with even increments (feet and inches, for example), and every person falls somewhere on the continuum for that trait.

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Species

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A group of organisms that can interbreed and produce fertile offspring; a reproductively isolated group of organisms.

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Population

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Within a species, an interbreeding group of individuals; the group among which an organism is most likely to find a mate; a group of organisms sharing a gene pool.

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Gene pool

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The total complement or store of genes in a population; described by allele frequency.

Front 49

Allele frequency

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Proportion (expressed as percentage) of different alleles in the gene pool of a population

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Evolution

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A change in the allele frequency in the gene pool of a population through time

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Mutation

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A change in allele frequency of a population can occur due to a change or alteration in genetic material in the gametes. A mutation is the only way to produce new variation that can then be acted upon by natural selection.

Front 52

Gene flow

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The exchange of genes between populations. A change in allele frequency of a population can take place due to movement of alleles into or out of populations.

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Genetic Drift

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A change in allele frequency of a population due to chance or random factors.

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Founder effect

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A type of genetic drift in which allele frequencies are altered in small populations that are taken from, or are remnants of, larger populations

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Natural selection

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A change in allele frequency of a population can take place due to differential individual net reproductive success

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Microevolution

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Small-scale changes in allele frequencies that can take place from generation to generation within a species.

Front 57

Macroevolution

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Large-scale evolutionary changes that lead to speciation, the development of a new species