Checkpoint Study guide/biology

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2.01

Adaptation: Characteristic-physical, chemical, or behavioral that helps an organism survive and reproduce is an adaptation.

The walking stick insect has characteristic camouflage which helps it to avoid predators.

The environment determines which adaptations will help an organism survive.

2.02

Define evolution:

Evolution occurs in a population when there is a genetic change in its allele frequencies that means, when the ratio of alleles has changed, evolution has occurred.

What is a population?

A population is a group of organisms that are the same species that live in the same shared space and reproduce with each other. Like the reef community, and fish.

2.04

What is a mutation?

A mutation is a change in an organism's DNA structure or sequence. A mutation is one way in which the alleles in a population can become more variable. A mutation will add a new allele to the gene pool. If that mutation results in an advantage to an individual, it may increase in the population over time.

The gene pool includes all the different alleles for each type of gene.

The change in allele frequency in population's gene pool over time is called evolution, so the ratios of allele's for a given trait can change.

Name four sources of genetic variation in populations:

Mutation

Genetic Recombination

Migration

Gene Flow

2.05

Vertebrate embryos develop in similar ways, suggesting that they share genes derived from a .... Common ancestor.

Vestigial Structures are features that appear to be necessary adaptations in the ancestors of modern day organisms, but when the environment changes, the structures lost their function for ex. flightless birds have wings even though they don't fly.

2.09

Evidence indicates that all life was a type of single cell prokaryotic that had no nucleus and didn't need oxygen to survive.

2.17

Evolutionary history/Phylogeny

1.03

DNA- It all starts with the DNA molecule in those cells. DNA contains the genetic instructions for making all of the proteins your body.

1.13

mRNA- Its structure is relatively simple it's a piece of single stranded RNA. It is made directly from DNA so it is a copy of the genetic code of DNA

tRNA- Like all RNA, tRNA is made in the cell's nucleus from DNA. A molecule of tRNA can be between 70 to 90 nucleotide sequences long and its job is to identify which amino acids the mRNA is coding for and bring them in.

rRNA- Molecules of rRNA which can be between 100-4,000 nucleotide sequences long are formed in the nucleus and migrate to the cytoplasm rRNA combines with many small proteins to make up a ribosome.

Where is DNA located within a cell during all of this?

The DNA is located in the nucleus of the cell and remains in the nucleus during all phases of protein synthesis.

Genetic code: The relationship in which each codon determines each amino acid used for making a protein. Codons match up with specific amino acids creating the genetic code. The genetic code connects codons from an mRNA strand to an amino acid the same genetic code is found in all organisms therefore is considered universal.