biology - my FINAL straw 😊🥊

What is DNA, why is it important?

What is DNA, why is it important?

Deoxyribonucleic acid Carries the genetic information of living organisms, and is the blueprint for their development, function, growth, and reproduction. It has instructions for an organism's height, eye color, hair color, etc.

What is the monomer of DNA? What are the 3 parts of this structure?

Nucleotides 3 parts: sugar molecule (deoxyribose), phosphate group, and a nitrogenous base The nitrogenous base is what we know as: Adenine, Thymine, Cytosine, and Guanine.

Why is DNA replication considered semi-conservative?

This is because each of the newly formed DNA molecules contains one strand of DNA from the parent, and one that is newly synthesized(daughter strand).

What is the central dogma? How is protein made?

Theory that describes the flow of genetic info in a biological system. DNA->RNA->Protein Protein is made through translation.

What's the difference between transcription and translation?

Transcription is the process where a segment of DNA is copied into mRNA. Translation is when mRNA is decoded by ribosomes to make a specific protein based on what instructions it got from the mRNA transcription- mRNA produced translation- protein produced

Where does replication, transcription, and translation take place?

Replication- happens in the nucleus of eukaryotic cells and the cytoplasm of prokaryotic cells Transcription- nucleus of eukaryotic cells and the cytoplasm of prokaryotic cells Translation- cytoplasm at the ribosomes in both prokaryotic and eukaryotic cells

What are DNA mutations?

Changes in the nucleotide sequence of DNA

How is the size of a cell related to how well it functions?

Larger cell may have a harder time efficiently transporting materials and wastes across its membrane Smaller cells have a better ratio of surface area to volume which allows them to have a better exchange of substances.

What is a chromosome?

Condensed and organized structure that is made up of DNA and proteins that carry genes.

What happens to chromosomes during the stages of Mitosis?

Chromosomes condense to become visible under a microscope, and align at the center of the cell, separate into two sets, and then move to opposite sides of the cell. Because of this, each daughter cell receives an identical set of chromosomes.

What's the difference between mitosis and cytokinesis?

Mitosis- produce two daughter nuclei, ensures that each daughter cell receives the correct amount of chromosomes Cytokinesis- division of cytoplasm to form two separate daughter cells, completes cell division process by dividing the cytoplasm

What is the difference between a cancerous cell and a normal cell?

Cancerous cell- lost the ability to control their growth and division, spread to other parts of the body, have genetic mutations that disrupt normal cellular functions

Know the difference between mitosis and meiosis.

Mitosis- results in two identical daughter cells Meiosis- produces gametes w/ half the number of chromosomes than the parent cell

Understand what crossing over and independent assortment are and when they occur during meiosis.

Crossing over is the exchange of genetic material between homologous chromosomes during meiosis Independent assortment is the distribution of homologous chromosomes during meiosis which leads to genetic diversity in their offspring Crossing over - Prophase I Independent Assortment - Metaphase I

What's the difference between a genotype and a phenotype?

Genotype - genetic makeup of an organism including the alleles that make up a particular trait Phenotype - physical characteristics that result from the genotype interacting with the environment

What's the difference between being homozygous and heterozygous?

Homozygous - AA aa Heterozygous - Aa

What is the difference between sexual and autosomal chromosomes?

Sex chromosomes determine an organism's biological sex Autosomal chromosomes determine other traits and characteristics

Understand the differences between codominance, incomplete dominance, multiple allele traits and polygenic traits.

Codominance - shows both alleles distinctly Incomplete dominance - shows a blending of traits Multiple allele traits - involve more than two alleles for a gene in a population Polygenic traits - controlled by multiple genes, resulting in a range of phenotypic variations

Understand what genetic diseases are and how they are passed down.

Caused by mutations in an organism's DNA sequence Can be inherited from the parents, if one or both of the parents has the gene then the offspring may receive it.

What is evolution?

How living things change over time

Who established the Theory of Evolution by Natural Selection? What was the name of the book he published? What island is famous for its relationship to the theory?

Charles Darwin On the Origin of Species Galápagos Islands

How are finches on the Galapagos Islands similar? How are they different?

All evolved from a common ancestor Have different beak shapes and sizes that they have adapted to the island they live on to help them better survive there.

How are tortoises on the Galapagos Islands similar? How are they different?

Similar in their general body structure Different in their shell shape and size

What are variations and adaptations? Give examples.

Variations- differences in traits among individual species Adaptations- traits that help organisms survive and reproduce in their environment. Bird having a long beak to reach nectar in flowers

Describe the process of Evolution by Natural Selection.

Organisms with traits better suited to their environment are more likely to survive and pass on those traits to their offspring

What are homologous structures? Give an example.

Body parts that are similar in structure but might have different functions Ex: wings of bats and arms of humans have a similar bone structure.

What are vestigial structures (give examples)

Body parts that have lost their original function because of evolution Ex: human appendix in and the wings of flightless birds

What is artificial selection? (give examples)

Humans choose which traits in plants or animals are desirable and breed them selectively Ex: breeding dogs for specific traits

What are the pieces of evidence for evolution?

Fossils, embryology, biogeography, molecular biology

How do permineralized fossils form? What needs to be present?

Minerals seep into the pores of an organism's remains and harden over time, and this preserves the structure. Dead stuff, water, chemical magic(check below), + time As the water flows through the buried stuff, it starts to soak up those minerals. These minerals act like a glue, sticking to the cells and tissues of the dead thing.

What is a half-life?

Time it takes for half of the atoms in a radioactive substance to decay

What are trace fossils? What are index fossils?

Trace fossils- footprints, burrows Index fossils- fossils of organisms that lived in specific time periods, this can be used to help date certain rock layers

How do scientists determine the age of fossils based on relative and absolute dating

Relative Dating - They look at the rock layers to determine the approximate age of fossils. Absolute Dating - This is like using a stopwatch to figure out exactly how long something took. Scientists use special clocks inside rocks and fossils. These clocks tick at a steady rate as they break down over time. By counting the ticks, scientists can figure out how long ago the rock or fossil formed.

What is a species? What is a population?

Species- group of organisms that can interbreed and produce fertile offspring Population- group of individuals of the same species that live in the same area

What is a gene pool?

Total collection of genes in a population at any time.

How do mutations and recombination affect a gene pool?

Mutations create new genetic variations recombination shuffles existing variations within a gene pool

What is directional selection? Stabilizing? Disruptive?

Directional selection- favors individuals at one extreme of a trait Stabilizing- favors the average trait Disruptive- favors individuals at both extremes

What is genetic drift?

Random change in allele frequencies in a population

What is the bottleneck effect?

Occurs when a population drastically reduces in size, and leads to a loss of genetic diversity

What is gene flow?

When genes transfer between populations through migration and interbreeding

What is speciation?

New species evolve from existing species

What is reproductive isolation? Behavioral Isolation? Geographical isolation? Temporal Isolation?

Reproductive isolation- individuals of different species are unable to successfully mate Behavioral Isolation - Think of it like this: animals have their own special ways of flirting. Some birds sing specific songs, while others do special dances. If two animals can't understand each other's flirting moves, they probably won't mate. That's behavioral isolation - when animals don't hook up because they don't understand each other's courtship rituals. Geographical Isolation - Imagine you and your friend live on opposite sides of a huge river. You can't meet up because there's no bridge or boat. Well, animals can get split up too. Mountains, rivers, oceans - these things can separate groups of animals. And when they're separated, they can't mate. So, even if they're the same species, they can become different just because they live in different places. Temporal Isolation - This one's about timing. Imagine you're a night owl, and your friend is an early bird. You're never awake at the same time, so you can't hang out. Animals can be like that too. Some might be ready to mate in spring, while others prefer summer. If their mating seasons don't match up, they won't make babies together.

How is convergent evolution related to analogous structures?

Different species evolve similar traits independently because of similar environmental pressures These similar traits are analogous structures

What is divergent evolution?

Related species evolve different traits because of different environmental pressures

Can you give an example of two species that have coevolved?

Flowering plants and their pollinators - bees

What is human caused global change?

Change where human activities impact the earth's environment on a large scale

Understand the basics of climate change/global warming.

Long-term changes in the earth's climate, including global warming Global warming- increase in earth's average surface temperature because of human activities like burning fossil fuels

What are greenhouse gasses?

Gasses in the earth's atmosphere that trap heat and add to the greenhouse effect. This leads to global warming

What is pollution?

Presence of harmful/toxic substances in the environment that cause harm to living organisms

What is smog and how do particulates affect smog?

Smog- big dirty cloud of air pollution, and particulates are like particles of dirt that make it even dirtier.

What is biomagnification? Why is this important to monitor?

Biomagnification- process where toxic substances become more concentrated in organisms higher up the food chain Important to monitor because it can lead to health risks for humans and wildlife

How can introducing a foreign species into a new area be a bad thing? A good thing?

Bad thing because this can disrupt the existing ecosystem, outcompete native species, and lead to a loss of biodiversity Good thing because this can control pests or improve soil quality

What is habitat fragmentation? Why does this cause a negative effect on species?

Habitat fragmentation- breaking up of habitat into smaller, isolated patches Can negatively affect species by reducing their available habitat, limit their ability to find food/mates, increase their vulnerability to threats

What two factors are needed to ensure sustainable development?

Balance economic growth with environmental protection and social equity Consider long term impacts of development on the environment and society