UNITS 5 & 6 Heredity / Gene Expression & Regulation

0.0(0)
studied byStudied by 0 people
GameKnowt Play
learnLearn
examPractice Test
spaced repetitionSpaced Repetition
heart puzzleMatch
flashcardsFlashcards
Card Sorting

1/59

encourage image

There's no tags or description

Looks like no tags are added yet.

Study Analytics
Name
Mastery
Learn
Test
Matching
Spaced

No study sessions yet.

60 Terms

1
New cards

purines

Bases with a double-ring structure.

2
New cards

pyrimidines

Bases with a single-ring structure.

3
New cards

mutation

Changes in the nucleotide sequence in DNA.

4
New cards

allele

One of the alternative forms of a gene that governs a characteristic, such as hair color.

5
New cards

asexual reproduction

One parent produces a genetically identical offspring by mitosis.

6
New cards

autosomes

Chromosomes that are not directly involved in determining the sex of an individual.

7
New cards

crossing over

Nonsister chromatids exchanging DNA segments.

8
New cards

diploid cell

Has two sets of chromosomes.

9
New cards

gametes

A haploid cell such as an egg or sperm that unite during sexual reproduction to produce a diploid zygote.

10
New cards

homologous chromosomes

Pair of chromosomes that are the same size, same appearance and same genes.

11
New cards

independent assortment

The random distribution of the pairs of genes on different chromosomes to the gametes.

12
New cards

karyotype

Photograph of chromosomes grouped in order and in pairs.

13
New cards

locus

The specific site of a particular gene on its chromosome.

14
New cards

sexual reproduction

When two parents give a unique combination of genes to offspring.

15
New cards

zygote

Fertilized egg. Carries one set of chromosomes from each parent.

16
New cards

true-breeding

Organisms that, when reproducing, create offspring of all the same variety.

17
New cards

P generation

The name for the true-breeding parents.

18
New cards

F1 Generation

The hybrid offspring of true-breeding parents.

19
New cards

The Law of Segregation

Two alleles separate during gamete formation and end up in different gametes because they are on homologous chromosomes.

20
New cards

recessive allele

An allele that is masked when a dominant allele is present.

21
New cards

homozygous

An organism having a pair of identical alleles for a character, either dominant or recessive.

22
New cards

phenotype

An organism's traits.

23
New cards

genotype

An organism's genetic makeup.

24
New cards

testcross

The result of breeding a recessive homozygote with an organism of dominant phenotype but unknown genotype.

25
New cards

codominance

When the phenotypes of both alleles are exhibited in the heterozygote.

26
New cards

incomplete dominance

Creates a blended phenotype; one allele is not completely dominant over the other.

27
New cards

pedigree

A diagram that shows the occurrence of a genetic trait in several generations of a family.

28
New cards

sex-linked genes

Genes located on the sex chromosomes.

29
New cards

linked genes

Genes located on the same chromosome that tend to be inherited together in genetic crosses.

30
New cards

nondisjunction

Error in meiosis in which homologous chromosomes fail to separate.

31
New cards

semiconservative model

Type of DNA replication in which the replicated double helix consists of one old strand, derived from the old molecule, and one newly made strand.

32
New cards

DNA polymerase

An enzyme that catalyzes the formation of the DNA molecule.

33
New cards

lagging strand

A discontinuously synthesized DNA strand that elongates by means of Okazaki fragments, each synthesized in a 5' to 3' direction away from the replication fork.

34
New cards

leading strand

The new continuous complementary DNA strand synthesized along the template strand in the mandatory 5' to 3' direction.

35
New cards

Okazaki fragments

Small fragments of DNA produced on the lagging strand during DNA replication, joined later by DNA ligase to form a complete strand.

36
New cards

helicase

An enzyme that untwists the double helix at the replication forks, separating the two parental strands and making them available as template strands.

37
New cards

transcription

Synthesis of an RNA molecule from a DNA template.

38
New cards

messenger RNA (mRNA)

Carries genetic message from the DNA to the protein-synthesizing machinery of the cell.

39
New cards

ribosomes

Complex particles that facilitate the orderly linking of amino acids into polypeptide chains.

40
New cards

template strand

The DNA strand that provides the template for ordering the sequence of nucleotides in an mRNA transcript.

41
New cards

promoter

A specific nucleotide sequence in DNA that binds RNA polymerase and indicates where to start transcribing mRNA.

42
New cards

RNA polymerase

Enzyme that links together the growing chain of ribonucleotides during transcription.

43
New cards

terminator

In prokaryotes, a special sequence of nucleotides in DNA that marks the end of a gene.

44
New cards

5' cap

The 5' end of a pre-mRNA molecule modified by the addition of a cap of guanine nucleotide.

45
New cards

exons

Coding segments of eukaryotic DNA.

46
New cards

codons

mRNA base triplets.

47
New cards

RNA splicing

Process by which the introns are removed from RNA transcripts and the remaining exons are joined together.

48
New cards

introns

Noncoding segments of nucleic acid that lie between coding sequences.

49
New cards

transfer RNA (tRNA)

Interpreter of a series of codons along a mRNA molecule.

50
New cards

ribosomal P site

Site that holds tRNA carrying the growing polypeptide chain.

51
New cards

ribosomal A site

Site that holds the tRNA carrying the next amino acid to be added to the chain.

52
New cards

Ribosomal E site

Site where discharged tRNAs leave the ribosome.

53
New cards

mutations

Random errors in gene replication that lead to a change in the sequence of nucleotides. The source of all genetic diversity.

54
New cards

point mutations

Chemical changes in just one base pair of a gene.

55
New cards

missense mutations

Most common type of mutation, a base pair mutation in which the new codon makes sense in that it still codes for an amino acid.

56
New cards

nonsense mutations

A mutation that changes an amino acid codon to one of three stop codons, resulting in a shorter and usually nonfunctional protein.

57
New cards

frameshift mutation

Mutation occurring when the number of nucleotides inserted or deleted is not a multiple of three, resulting in improper grouping of nucleotides into codons.

58
New cards

polymerase chain reaction (PCR)

A technique for amplifying DNA in vitro by incubating with special primers, DNA polymerase molecules, and nucleotides.

59
New cards

gel electrophoresis

The separation of nucleic acids or proteins, on the basis of their size and electrical charge, by measuring their rate of movement through an electrical field in a gel.

60
New cards

stem cell

Unspecialized cell that can both reproduce itself indefinitely and differentiate into specialized cells of one or more types.