Biology Semester 2 Ch 7-12 Final SG

What does DNA stand for?

Deoxyribose nucleic acid

What are bacteriophages?

Viruses that infect and kill bacteria

What are the 3 roles of DNA?

Store and copy information and express genes

What are the components of DNA?

Nucleic acids and nitrogenous bases

How do DNA base pairs match up?

Adenine and thymine, and guanine and cytosine.

What were Franklin’s and Watson and Crick’s contributions to science?

They illustrated and explained a double helix model.

What are the 3 parts of the double helix model?

Antiparallel strands, hydrogen bonding, and base pairing

Prokaryotic DNA replication

DNA is a circular ring that is free floating in the cytoplasm.

Eukaryotic DNA replication

DNA is found as chromosomes in the nucleus.

What does RNA stand for?

Ribonucleic acid

What are the roles of RNA?

Helps put the genetic code of DNA into action.

What is messenger RNA?

Used to make protein and travels to the cytoplasm to synthesize ribosomes.

What is ribosomal RNA?

Responsible for protein synthesis and occurs in ribosomes made up of subunits

What is transfer RNA?

Carry amino acids from the cytoplasm to the messenger RNA

What are promoters?

Encourages RNA synthesis.

What are the steps in translation?

Ribosomes attach to mRNA in the cytoplasm, and translation starts when the start codon is found. tRNA brings amino acids into the ribosome as each codon passes through.

How does a codon wheel work?

Start in the middle with the first letter of the codon and work outwards to find the second and third bases. The corresponding word reveals the amino acid.

What is a mutation?

Changes in the sequence of nucleotides or in the number or structure of chromosomes.

What are the different types of mutations?

Point and chromosomal mutations

What are the different types of point mutations?

Substitutions, insertions, deletions.

What are the different types of chromosomal mutations?

Deletion, duplication, inversion, translocation

What were Gregor Mendel’s contributions to science?

Genetics and the role of fertilization

What was Mendel’s job?

A teacher

What plant did Mendel use?

Pea plant

How many alleles do organisms have for each characteristic?

2

How many alleles come from each parent?

1

How can dominant traits be shown?

At least one dominant allele is present

How can recessive traits be shown?

Both alleles must be recessive

What is homozygous?

2 identical alleles for a gene.

What is heterozygous?

2 different alleles for a gene

What is a diploid?

Contains 2 sets of a homologous chromosomes

What is a haploid?

contains a single set of chromosomes

What is segregation in terms of genetics?

When each parent passes a copy of their gene to the offspring.

What is genotype?

Genetic makeup

What is phenotype?

Physical traits

What is incomplete dominance?

One allele is not completely dominant over the other.

What is codominance?

Phenotypes produced by both alleles are clearly expressed.

What are genes controlled by multiple alleles?

A gene with more than 2 forms

What are polygenic traits?

Produced by the interaction of several genes.

What happens in meiosis?

The number of chromosomes per cell is cut in half through separation of homologous chromosomes in a diploid cell.

When does crossing over occur?

Prophase 1

How do punnent squares work?

Shows the possible offspring of parents based on their genes.

What is mitosis?

Cell division resulting in 2 daughter cells

What is ecology?

The study of nature’s houses.

Why should we study ecology?

So we can learn and interact with organisms, populations, and communities and their interaction with the environment.

What is are species?

A group of similar organisms that can breed together.

What are populations?

A group of individuals in a species that live in the same area.

What are communities?

Different populations living in the same area.

What are ecosystems?

Every living and nonliving thing of an environment is found in a specific location.

What are biomes?

Group of ecosystems

What is a biosphere?

All the biomes

What are biotic factors?

Living things

What are abiotic factors?

Nonliving things

What are primary producers?

The first producers of energy rich compounds that can be used later by other organisms.

What is a keystone species?

A species that can influence an entire community and change ecosystems.

What are the three types of symbiosis relationships we discussed?

Commensalism, mutualism, parasitism

What is a global footprint?

The total area of healthy land and water ecosystems need to provide resources you use.

What is the main greenhouse gas?

Carbon dioxide

How has climate change impacted the Earth?

Greenhouse gas concentration is rising leading to climate change.

What is an anthrobiome?

Human altered biomes where there is little land left.

What is an anthropocene?

When human activity is the main cause of climate change.

What should be considered while designing sustainable resources?

Using resources that preserve ecosystems, and can be produced or replaced by these ecosystems.

What is biological magnification?

Pollutants are not broken down when picked up by organisms.

What is ocean acidification and what impact can it have?

When burning fossil fuels releases a large amount of carbon dioxide that dissolves in seawater that stresses marine organisms and ecosystems.

What is habitat fragmentation?

Natural habitats that are completely changed.

What are biological islands?

Areas suited for specific ecosystems.

What are invasive species?

Nonnative species that cause economic, environmental, or human harm.

How has and can climate change impact agriculture?

Agriculture releases methane

Speies vary locally

Different but related species occupy different habitats in the same area.

Species vary globally

Different but ecologically related species living in different but ecologically similar environments

Species vary over time

Extinct species that are similar to living organisms.

What is artificial selection?

Selective breeding

What is natural selection?

Nature chooses what genes are passed on

What is fitness?

How well an organism can survive and reproduce

What is biogeography?

Explains how modern organisms evolved from their ancestors.

What are homologous structures?

Similar structures with different functions.

What are vestigial strucutres?

Structures that have lost most of their original size and function.

What are analogous strucutres?

Different structures that share a common function.

How do mutations affect evolution?

A  change in genetic information that can lower or higher the fitness or phenotypes of an organism.

How does genetic recombination affect evolution?

It causes differences in relatives which can lead to a greater genetic variation.

How does natural selection act on single-gene traits?

2-3 phenotypes

How does natural selection act on polygenic traits?

Controlled by 2 or more genes with many possible genotypes. Leads to directional, disruptive, or stabilizing selection.

What is directional selection?

Organisms at one end of the curve have higher fitness than others and the range of phenotypes shift.

What is stabilizing selection?

Organisms near the middle of the curve have higher fitness.

What is disruptive selection?

Phenotypes at both ends of the curve become more common.

What is genetic drift?

A frequency change in a gene due to a random change.

What are genetic bottlenecks?

When many organisms die off, leaving a diverse gene pool.

What is the founder affect?

When organisms leave and colonize their own area.

What is the Hardy-Weinberg Principle?

Allele frequencies in a population should remain constant unless one or more factors cause change.

The bases of DNA are ___.

Nitrogenous

Nucleotides are joined together to form the sides of the DNA "ladder" by what type of bonds?

Covalent

Nirtrogenous bases are joined together to form rungs of the DNA ladder with what bonds?

Hydrogen

The enzyme responsible for unzipping DNA by breaking hydrogen bonds between base pairs is called

DNA helicase

The enzyme responsible for joining nucleotides to complementary strands of DNA is called

DNA polymerase

A mutation that causes translation to stop before the protein was actually finished

Nonsense

A mutation that causes no change to proteins as the amino acid is the same

Silent

A mutation that causes every amino acid after it to change

Frameshift

Chemical or physical agents in the environment that increase the risk of mutations

Mutagens

When male and female reproductive cells join to produce a new cell called a zygote

Fertilization

Offspring from parents with different traits

Hybrids