Science final

What’s the basic building block of DNA?

Nucleotides

Name three components of a nucleotide.

Nitrogenous base, deoxyribose sugar, and a phosphate group.

What is DNA replication?

The copy of DNA which creates 2 identical molecules.

In DNA, Adenine (A) always bonds with..

Thymine

Cytosine (C) always bonds with…

Guanine

In RNA, Adenine (A) always bonds with…

Uracil

Guanine (G) always bonds with…

Cytosine

mRNA means…

Messenger RNA (blueprint): carries instructions to ribosome to a cytoplasm creating a protein.

rRNA means…

Ribosomal RNA (factory RNA): connects amino acid into protein chains.

tRNA means…

Transfer RNA (delivery RNA): carries amino acids to ribosomes (proteins).

What is the difference between transcription and translation? What type of RNA is responsible for each step?

Transcript is the change from DNA→ RNA while translation decodes mRNA.

What is a codon? What is it used for?

A sequence of 3 nucleotides in DNA or RNA that codes for an amino acid.

Ribosomes make..

Proteins!

Proteins are made up of…

Ribosome and amino acids

What are the 5 steps in protein synthesis?

DNA → DNA → mRNA → tRNA → Proteins

What is a mutation?

A change in DNA sequence

Temporal isolation is..

Not reproducing at the same time

What is a point mutation? How could this mutation happen?

Change within DNA - RNA, can be substitution, insertion, and deletion

What is a frame shift mutation? How could this mutation happen?

Addition or deletion → 1 nucleotide base happens when sequence disrupts and after inserts deletation

What is genetic engineering?

Process of modifying organism’s DNA to have desirable traits.

What is recombinant DNA? Provide some example where this technology is used?

Artificial DNA formed by combinations of 2 or more gene sequences.

Define natural selection?

A mechanism of evolution.

Does natural selection act on genotypes or phenotypes? Explain.

Natural section acts on phenotypes → phenotypes are better suited to their environment

What are adaptations?

Developing traits to enchanted survival in new environment.

What was Darwin’s theory of evolution? Identify 5 points from Darwin’s theory.

How species change over time for an organism to better survive.

Variation, inheritance, over production, survival, and differential production.

What is adaptive variation and its significance?

Changes for an organism to better survive.

How would you define genetic drift?

A change in frequency of a gene (small population).

Describe 5 main types of evidence that can be used to support the theory of evolution.

Fossils, anatomy, embryology, molecular biology, and biography

What is the difference between homologous and analogous structures?

Homologous is structures similar in appearance (shared ancestry) and analogous is similar structure w/o shared ancestry.

What leads to speciation?

Reproductive isolation (cannot interbreed).

What is the difference between stabilizing, directional, and disruptive selection?

Stabilizing: high fitness, directional: extreme fitness, disruptive: upper and lower fitness

What is the difference between geographical and behavioral isolation? Provide an example for each.

Geographical = study of natural features of the earths surface, behavioral = Behavior of an organism.

Identify natural selection and evolutionary changes from scenarios.

Natural selection = heritable traits and population change overtime, evolutionary = altercation of heritable traits within a population over successive generations

what is biodiversity?

Variety on earth.

What contributes to a stable ecosystem (balanced)?

High biodiversity, nutrients, and resistance to disturbances.

What are biotic and abiotic factors in an ecosystem? Provide examples.

biotic = Living things, ex: animals. Abiotic = nonliving, ex: sun, and water.

What are some factors that can disrupt an ecosystem? Describe the impact humans have.

Earthquakes, volcanic, eruptions, floods, and droughts.

Humans = Pollution/climate change.

What is an invasive species?

Non-native organisms that cause harm.

What is a keystone species and how does it impact trophic cascade in an ecosystem?

Keystone species = indirect effects Of an ecosystem. It can also cause trophy cascades that could affect levels.

What is the difference between an autotroph and a heterotroph?

autotroph = automatically producing your own food. Heterotroph = gets food by consuming other organisms.

Distinguish between producers, consumers, and decomposers? Provide examples.

Producers = Make food (plants). Consumers = Eat (animals). Decomposers = breakdown (fungi.

In an energy pyramid, how does energy flow what percentage goes to the next trophic level?

Flow bottom to top as organisms consume. (10%).

How do primary producers get their energy?

The sun.

What are the differences between primary and secondary succession?

Primary = Bare rock with new soil. Secondary = occurs in a previous community that existed and was disturbed.

rRNA means…

Ribosomal RNA (factory RNA): connects amino acid to a ribosome (proteins).