Unit 4-Chapters 6, 7, 8, and 9 Flashcards
Vocabulary and Key Ideas
You have ___ and ___
Body cells and gametes
Your cells have ___ and ___ chromosomes
autosomes and sex
Body cells are ___; gametes are ___
diploid and haploid
somatic cells
same as body cells
make up most body tissues and organs
gamete cells
same as sex cells
eggs/ova in females
sperm/spermatozoa in males
homologous chromosomes
2 chromosomes-one from ma and one from pa-that have the same length and general appearance
autosomes
chromosomes that contain genes for characteristics not directly related to the sex of an organism
3 names for body cells
body
somatic
diploid
3 names for sex cells
sex
gamete
haploid
sexual reproduction
involves the fusion of two gametes that results in offspring that are a genetic mixture of both parents
fertilization
the actual fusion of an egg and sperm cell
diploid
when a cell has two copies of each chromosome: one from ma and one from pa
haploid
a cell that has only one copy of each chromosome
meiosis
a form of nuclear division that divide a diploid cell into haploid cells
cells go through… during meiosis
two rounds of division
haploid cells develop into…
…mature gametes
___ laid the groundwork for genetics
Mendel
Mendel’s data revealed…
…patterns of inheritance
trait
distinguishing characteristics that are inherited
genetics
the study of biological inheritance patterns and variation
purebred
organisms that are genetically uniform
cross
mating of two organisms
law of segregation
- organisms inherit 2 copies of each gene (one from each parent)
- organisms donate only one copy of each gene in their gametes
the same gene can have…
…many versions
genes influence the…
…developement of traits
gene
a piece of DNA that provides a set of instructions to a cell to make certain protein
allele
any alternative forms of a gene that may occur at a specific locus
homozygous
2 of the same alleles at a specific locus
heterozygous
2 different alleles ata specific locus
genome
all of an organism’s genetic material
genotype
refers to the genetic makeup of a specific set of genes
phenotype
the physical characteristics or traits of an individual organism
dominant
the allele that is expressed when two different alleles or two dominant alleles are present
recessive
the allele that is only expressed when two copies are present
punnet squares illustrate…
…genetic crosses
a monohybrid cross involves…
…one trait
a dihybrid cross involves…
…two traits
heredity patterns can be calculated with…
…probability
punnett square
a grid system for predicting all possible genotypes resulting from a cross
monohybrid crosses
crosses that examine the inheritance of only one specific trait
testcross
a ccross between an organism with an unknown genotype and an organism with the recessive phenotype
dihybrid crosses
crosses that examine the inheritance of two different traits
law of independent assortment
allele pairs separate independently of each other during gamete formation/meiosis
2 copies of each autosomal gene…
…affect phenotype
males and females can differ in…
…sex-linked traits
carrier
does not show disease symptoms, but can pass on the disease-causing allele to offspring
sex-linked genes
genes that are located on the sex chromosomes
X chromosome inactivation
when one of the two X chromosomes is randomly tunred off
phenotype can depend on…
…interactions of alleles
many genes interact to produce…
…one trait
the environment interacts with…
…genotype
incomplete dominance
when a heterozygous phenotype is somewhere between the two homozygous phenotypes
codominance
when both traits are fully and seperately expressed
polygenic traits
traits produced by two or more genes
human genetics follow…
…the patterns seen in other organisms
females can carry…
…sex-linked genetic disorders
a pedigree is a…
…chart for tracing genes in a family
several methods help map…
…human chromosomes
pedigree
a chart that can help trace the phenotypes and genotypes in a family to determine whether people can carry recessive alleles
karyotype
a picture of all the chromosomes in the cell
DNA is composed of…
…four types of nucleotides
Watson and Crick developed…
…an accurate model of DNA’s 3-D shape
nucleotides always…
…pair in the same way
nucleotide
the small units/monomers that make up DNA
double helix
the shape of DNA
2 strands of DNA wind around each other like a twisted ladder
base pairing rules
bases of the 2 DNA strands always pair up in the same way
T with A
C with G
replication copies…
…genetic information
proteins carry out…
…the process of replication
replication is…
…fast and accurate
replication
process by which DNA is copied during the cell cycle
DNA polymerases
a group of enzymes that band the new nucleotides together
RNA carries…
…Dna’s instructions
Transcription makes…
…three types of RNA
the transcription process is similar to…
…replication
central dogma
a theory that states that, in cells, information only flows from DNA to RNA to proteins
RNA
ribonucleic acid
a chain of nucleotides
transcription
the process of copying as sequense of DNA to producs a complementary strand of RNA
RNA polymerase
an enzyme that bonds nucleotides together in a chain to make a new RNA molecule
messenger RNA (mRNA)
the message that is translated to make a protein
ribosomal RNA (rRNA)
forms part of ribosomes
transfer RNA (tRNA)
brings amino acids from the cytoplasm to a ribosome to help make the growing protein
translation
the process that converts or translates and mRNA message into a polypeptide
codon
a three-nucleotide sequence that codes for an amino acid
stop codons
3 of them: UGA: UAA: UAG
signal the end of the amino acid chain
start codon
AUG: methionini
signals the start of translation
anticodon
a set of three nucleotides that is complementary to an mRNA codon
scientists use several techniques to…
…manipulate DNA
restriction enzymes cut…
…DNA
restriction maps shoe the…
…lengths of DNA fragments
restriction enzyme
enzymes that cut DNA molecules at specific nucleotide sequences
gel electrophoresis
an electircal current is used to separate a mixture of DNA fragements from each other
restriction maps
show the lengths of DNA fragments between restriction sites in a strand of DNA
a DNA fingerprint is a type of…
…restriction map
DNA fingerprinting is used for…
…identification
DNA fingerprint
a representation of parts of an indviduals DNA that can be used to identify a person at the molecular level
entire organisms can be…
…cloned
new genes cab be added to..
…an organisms DNA
Genetic engineering produces…
…organisms with new traits
clone
a genetically identical copy of a gene or of an organism
genetic engineering
changing of an organism’s DNA to give the organism new traits
recombinant DNA
DNA that contains genes from more than one organism
plasmids
closed loops of DNA that are separate from the bacterial chromosome and that replicate on their own within the cell
transgenic
an organism that has one or more genes from another organism inserted into its genome
gene knockout
genetic manipulation in which one or more of an organism’s genes are prevented from being espressed
genomics involves…
…the study of genes, gene functions, and entire genomes
technology allows the study and comparison of both…
…genes and proteins
genomice
the study of genomes
gene sequencing
determining the order of DNA nucleotides in genes or genomes
Human Genome Project
two main goals:
- to map and sequence all of the DNA base pairs of the human chromosomes
- to identify all of the genes within the sequence
bioinformatics
the use of computer databases to organize and analyze biological data
DNA microarrays
tools that allow scientists to study many genes and their expression at once
proteomics
the study and comparison of all the proteins that result from an organisms genome
