Semester 2 Bio Final

DNA

DNA

information

Codon

3 nucleotides in a sequence for an amino aid

Anticodon

set of three nucleotides that compliment the mRNA

rRNA

ribosomal RNA, part of ribosome

mRNA

messenger RNA, is the info transcribed from the DNA

tRNA

transfer RNA, brings amino acids to ribosomes to make protein

Carcinogens

radiation, smoking, the sun

What is Replication

process in which DNA is copied

First step of replication

DNA is unwound from double helix, and unzipped by helicase. This step breaks the hydrogen bonds.

Second step of DNA replication

Free nucleotides are hydrogen bonded to their complimentary base pair

DNA polymerase

enzyme that bonds nucleotides to the strand

only work s on 5’ to 3’

Leading stand

flows smoothly

lagging strand

works in pieces

Ligase

glue for lagging strand

Third step of DNA replication

results in 2 identical strands. 1 new strand and 1 original strand.

Where does DNA replication occur in Prokaryotes (bacteria)?

cytoplasm

Where does DNA Replication occur in Eukaryotes (plants and animals)?

Nucleus

Transcrption

The cell makes a RNA copy of a piece of DNA

Where does Transcription occur?

nucleus

What replaces Thymine in RNA?

Uracil

What is RNA?

chain of nucleotides

What is the first step of transcription?

Initiation

What happens in Intiation?

RNA polymerase unwinds the DNA, bonds nucleotides

What is the second step of transcprtion?

Elongation

What happens in Elongation?

complementary nucleotides are added to 3’ and mRNA

What is the third step of transcription?

Termination

What happens in Termination?

mRNA detaches from the DNA, and exits through nuclear pore.

Translation

the process that converts mRNA to a polypeptide

Where does translation occur?

cytoplasm

What occurs in the first step of translation?

codon attaches to the complimentary mRNA

What occurs during the second step of translation?

Ribosome forms peptide bond amino acids

What occurs in the third step of translation?

Ribosomes pull the mRNA, so the tRNA exits. Now, a new mRNA is open ans new tRNA will arrive.

What does RNA have instead of Thymine?

Uracil

Can the DNA or the RNA leave the nucleus?

RNA

DNA is involved in?

transciption

RNA is involved in?

Transcription and Translation

What is the function of mRNA?

carry genetic info needed to make proteins

What is the function of rRNA?

to help translate the information mRNA into protein.

What is the function of the tRNA?

bring amino acids to the ribosomes to make proteins

What is insertion?

Frameshift mutation

Why is insertion and deletion bad?

Changes that protein and all others after that

What is deletion?

Deletes something where it was supposed to be, causes a frameshift

What is a nonsense substitution?

When protein ends too early

Why is a nonsense substitution harmful?

It may not have all the proteins it needs

Homozygous

Pure breed

Heterozygous

Hybrid

Gregor Mendel

Did an experiment with pea plants and discovered some traits were dominant

Allele

piece of chromosome that codes for a certain system

Genotype

genes

Phenotype

physical appearance

Sex-linked inheritance

characteristics influenced by genes on sex chromosomes

Why is there a reduction of chromosomes in Meiosis?

To ensure during the union of two gametes in fertilization, there is not double the needed amount of chromosomes

What does the reduction of chromosomes make possible?

Diplody

Diplod

having two complete sets of chromosomes in an organism with each parent contributing a chromosome to each pair

Zygote

a cell formed by the union of two sex cells

Prophase 1

Spindle fibers form and nucleus breaks down

What happens to chromosomes in prophase 1?

Homologous chromosomes line up in tetrads, and chromosomes cross over

Homologous chromosomes

2 chromosomes in a pair- normally one inherited from the mother and one from the father

Metaphase 1

pairs of homologous chromosomes line up

Anaphase 1

pulled to poles by spindles

Telophase 1

Cytoplasm divides 2 diploid cells

Prophase 2

new spindle fibers form and nucleus fades

Metaphase 2

individual chromosomes line up in the middle

Anapahse 2

centromeres divide to poles

Telophase 2

4 haploid cells form

How does meiosis provide genetic variation?

Creates new combinations of genetic material in each of the 4 daughter cells

Are gametes haploids or diploids?

haploids

When are genes more likely to be linked?

ones that are closer to each other on chromosomes

Incomplete dominance

Neither genes are dominant, appears as a blend

Co dominance

Both genes are dominant, and both appear

What are the possible genotypes fro someone who is type A blood?

AA or AO

Which chromosome more commonly has the genetic disorders?

The X chromosome

Why does the X chromosome more commonly have the genetic disorders?

both men and women have x chromosomes

Relative dating

looking at where it is in the rock layers to determine age

Natural selection

the fittest survive and reproduce, those who are not fit die off

Evolution

change over time

Fitness

organisms will survive and reproduce more often

Adapation

any trait that increases fitness

Niche

an organism’s role in an ecosystem

Artificial selection

humans change species by breeding for certain traits

Founder effect

new colony is started by only a few members

Bottleneck effect

population declines to a low number, but then rebounds

Homologous structures

same structures but different functions

Analogous structures

same functions but different structures

Vestigial structures

structure that has lost most or all function, but is still present

Taxonomy

naming and classifying of animals

Embryology

study that compares organisms’ fetus in early stages

Divergent evolution

1 species gives rise to many species

Convergent evolution

2 unrelated species develop similar traits due to similar enviorments

Co-evolution

species evolve as result of a close relationship

What is some evidences of evolution?

• Homologous structures

• Vestigial structures

• Embryology

What is a key difference in artificial and natural selection?

Artificial selection does not always breed for the most beneficial traits

Reproductive isolation

a species cannot breed

How could a species become reproductively isolated?

• Temporal isolation

• geographic barrier

• behavioral

Polyploidy

extra chromosome, makes it so you can not have offspring

Abiotic

non living

Biotic

living

Symbiosis

when organisms interact with one another

Parasitism

one organism is benefited while the other is harmed

Commenalism

one organism is benefited while the other is not affected