GENETICS

Scientists who discovered the structure of DNA...

James Watson and Francis Crick

Female scientists who often is not credired for her contributions in disocvering the structure of DNA....

Rosalind Franklin

Describte the structure of DNA

double twisting helix

DNA belongs to the group of organic compounds known as...

nucleic acids

What are the two groups of nucleic acids?

DNA and RNA

DNA stands for

deoxyribonucleic acid

RNA stands for

ribonucleic acid

What are the building blocks of nucleic acids?

nucleotides

What is the structure of a nucleotide?

5 carbon sugar, phosphate group, nitrogenous base

Compare DNA and RNA

1. DNA is double stranded and RNA is single stranded 2) DNA contains the sugar deoxyribose and RNA contains the sugar ribose

2. DNA the nitrogen bases A,T, G, C and RNA has the nitrogen bases A, U, G, C

3. DNA stays in the nucleus. There are 3 types of RNA and they can move throughout the cell.

Name the three types of RNA...

mRNA, tRNA, rRNA

What does mRNA stand for

messenger RNA

What does tRNA stand for

transfer RNA

What does rRNA stand for

Ribosomal RNA

What if Gregor Mendel known for

The father of genetics

What did Gregor Mendel study?

pea plants

Name Mendel's Laws

dominant and recessive alleles
law of segregation
law of independent assortment

Law of Segregation

Mendel's law that states that the pairs of homologous chromosomes separate in meiosis so that only one chromosome from each pair is present in each gamete

Law of independent assortment

Mendel's second law, stating that allele pairs separate from one another during gamete formation

Dominant allele

one whose trait always shows up in the organism when the allele is present; in genetics problems represented with a capitol letter

Recessive allele

An allele that is masked when a dominant allele is present; in genetics problems represented with a lower case letter

Allele

Form of a gene

Gene

A segment of DNA on a chromosome that codes for a specific trait

Chromosome

a threadlike structure of nucleic acids and protein found in the nucleus of living cells, carrying genetic information in the form of genes.

Codominance

A condition in which both alleles for a gene are fully expressed

Codominance example

AB blood type

Name the alleles involved in blood types.

IA \= IB
i

incomplete dominance

A pattern of inheritance in which two alleles, inherited from the parents, are neither dominant nor recessive. The resulting offspring have a phenotype that is a blending of the parental traits.
The heterozygous individual has a new phenotype different from either parent.

Test cross

the crossing of an individual of unknown genotype with a homozygous recessive individual to determine the unknown genotype

Job of tRNA

carry amino acids to ribosomes

Job of mRNA

to carry the code of DNA from the nucleus to the ribosomes for making a protein

Job of rRNA

makes up ribosomes

Karyotype

A picture of all the chromosomes in a cell arranged in pairs

Sex chromosomes in humans

are either X or Y. *female: XX* *male: XY*

Somatic cells

body cells

Autosomes

Any chromosome that is not a sex chromosome

Diploid

2n
containing two complete sets of chromosomes, one from each parent.

Haploid

n
An organism or cell having only one complete set of chromosomes.

The human diploid chromosome number is

46

The human haploid chromosome number is

23

What cells of the body contain the diploid chromosome number?

body (somatic) cells

What cells of the body contain the haploid chromosome number?

sex cells (gametes)
egg and sperm

Name the two steps of protein synthesis

transcription and translation

Define transcription

The process of copying the genetic code from DNA into the form of mRNA
Happens in the nucleus

Define translation

Assembling a protein using the message carried by mRNA
Happens at ribosomes

sex

linked traits

Name three sex linked traits

hemophilia, baldness, colour blindness

Genotype

An organism's genetic makeup, or allele combinations.

Phenotype

An organism's physical appearance, or visible traits.

karyotype

the number and visual appearance of the chromosomes in the cell nuclei of an organism or species.

Homologous chromosomes

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

Sex chromosomes

X and Y chromosomes in humans
Females XX, males XY
One of the 23 pairs of chromosomes in the human, contains genes that will determine the sex of the individual.

homozygous

An organism that has two identical alleles for a trait

heterozygous

An organism that has two different alleles for a trait

Trisomy

In humans, 2n = 47
a condition in which an extra copy of a chromosome is present in the cell nuclei, causing developmental abnormalities.

trisomy 21

monohybrid cross

A cross between individuals that involves one pair of contrasting traits

Genetics

The scientific study of heredity

Punnett Square

A chart that shows all the possible combinations of alleles that can result from a genetic cross

Monosomy

In humans 2n \= 45
Chromosomal abnormality consisting of the absence of one chromosome from the normal diploid number

Somatic cell

any cell of a living organism other than the reproductive cells.

dihybrid cross

Cross or mating between organisms involving two pairs of contrasting traits

codon

three

anticodon

group of three bases on a tRNA molecule that are complementary to an mRNA codon

If this is a strand of DNA, what is the complementary strand of DNA?
ATGCCCTAG

TACGGGATC

If this is a strand of DNA, what is the stand of mRNA?
ATGCCCTAG

UACGGGAUC

DNA

A complex molecule containing the genetic information that makes up the chromosomes.
Deoxyribonucleic acid

How many chromosomes are present in a human stomach cell?

46

Are gametes haploid or diploid?

haploid

Is a zygote haploid or diploid?

diploid

Gregor Mendel

Augustinian monk and botanist whose experiments in breeding garden peas led to his eventual recognition as founder of the science of genetics (1822

In genetic crosses, the generation produced by the parents?

F1

Mendel's Principal of Dominance states:

one allele for a trait is able to mask another allele for the same trait.

Genotype

genetic makeup of an organism

Phenotype

An organism's physical appearance, or visible traits.

Heterozygous (hybrid)

having two different alleles for a trait

Homozygous

An organism that has two identical alleles for a trait

Mendel's phenotypic ration for a dihybrid cross between 2 heterozygous parents:

9:3:3:1

Test Cross

the crossing of an individual of unknown genotype with a homozygous recessive individual to determine the unknown genotype

Female sex chromosomes in humans

XX

Male sex chromosomes in humans

XY

Sex linked traits

Traits controlled by genes located on sex chromosomes.

Incomplete dominance

A pattern of inheritance in which two alleles, inherited from the parents, are neither dominant nor recessive. The resulting offspring have a phenotype that is a blending of the parental traits.
Red flower crossed with white flower produces pink flowers.

An organism with the following genotype XxYy produces how many gametes?

4

Gene

Sequence of DNA that codes for a protein and thus determines a trait
Nucleotide base sequence

Mutation

A change in a gene or chromosome.
A change in genetic material

What plant did Mendel study?

pea plants

Monohybrid cross

A cross between individuals that involves one pair of contrasting traits

Mendel's monohybrid cross phenotypic ratio:

three dominant to one recessive

Mendel's Law of Segregation

The two alleles of a gene found on each of a pair of chromosomes segregate independently of one another into sex cells.
A pair of alleles separate from each other during gamete formation.

Genetic engineering

A technology that includes the process of manipulating or altering the genetic material of a cell resulting in desirable functions or outcomes that would not occur naturally.

Building blocks of nucleic acids are called?

nucleotides

The three parts of a nucleotide are:

sugar, phosphate, nitrogen base

DNA replication results in:

2 identical DNA molecules that each contain a strand of the original DNA.
DNA replication is called a semi conservative process.

Chromosomes are made of

DNA and protein

The job of tRNA is to

Deliver amino acids to the mRNA strand
Act as an interpreter between the mRNA and the amino acids.

mRNA carries the code from the DNA to the nucleus to the....

ribosomes

If the mRNA has a codon AGU, what would the DNA sequence for this have been?

TCA

If the messenger RNA codons read UAU

GCU, what is the correct sequence of the tRNA anticodons?

autosomes

Any chromosome that is not a sex chromosome

sex chromosomes

X and Y chromosomes.