Exam #2

How do biologists define a species?

According to measurable physical traits, solely on the basis of molecular data, a sort of bar code that identifies each species, or as the smallest group of individuals sharing a common ancestor and forming one branch on the tree of life.

Phenylketonuria (PKU)

Accumulation of phenylalanine in blood; Lack of normal skin pigment; Developmental disabilities unless treated.

What is misleading about the term "gap" relative to phases in the cell cycle?

Although the G phases are called "gaps", cells are actually quite active and grow throughout all three subphrases of interphase.

How many individuals does Down syndrome effect?

1 / 850 children.

How many autosomes (chromosomes other than sex chromosomes) do both females and makes have?

44 Autosomes.

How many chromosomes are there in Turner syndrome (female) ?

45.

What is the make up of the chromosomes in a human body

46 chromosomes total. Autosomes and two different Sex chromosomes.

How can one describe the genetic bases of many human characters, such as eye and hair color?

Complex and poorly understood.

What is an example showing the importance of Epigenetic inheritance?

Components of chromosomes can be chemically modified by adding or removing chemical groups on the DNA and/or protein components of chromosomes.

What is the the result of the colorblindness gene being recessive?

A female will be colorblind only if she receives that allele on both X chromosomes.

Sex-linked gene

A gene located on a sex chromosome.

Clone

A group of genetically identical individuals.

Character

A heritable feature that varies among individuals.

Tumors

Abnormally growing masses of body cells.

What happens because energy cannot be absorbed relative to chloroplast pigments?

Absorbed energy must be converted to other forms.

What did Mendel create and how?

Created purebred varieties of plants and crossed two different purebred varieties. Did this by pollinating plants by hands so he was walks sure of the parentage of his new plants.

Genetic cross

Cross-fertilization.

Reduced Hybrid Fertility

Female horse mates with a male donkey to produce a mule (which is the best of both worlds). If it is a male horse with a female donkey, it produces a hinny which is stupid and useless.

What is the overall effect of the transfer of electrons during cellular respiration is a downward trip for electrons?

Form glucose, to NADH, to an electron transport chain, and to Oxygen.

What do membranes within the chloroplast form?

Form the framework where many of the reactions of photosynthesis occur.

What does the fossil record reveal about mass extinctions?

Fossil record reveals five mass extinctions over the last 540 million years. In each of these events, 50% or more of Earth's species died out The Permian mass extinction, at about the time Pangea formed, claimed about 96% of marine species and impacted extraterrestrial life as well The Cretaceous extinction occurred about 66 million years ago and included the extinction of all dinosaurs except birds, permitting an explosive increase in diversity of mammals Extinction seems to have provided the surviving organisms with new environmental opportunities.

What are fossils evidence for?

Fossils are evidence of organisms that lived in the past. The fossil record is the sequence in which fossils appear in rock strata and an archive of macroevolution.

What did Gregor Mendel find in the 1860s?

Found that parents pass on to their offspring discrete genes (which he called "heritable factors"), Genes are responsible for inherited traits, and Genes retain their individual identities generation after generation.

What does the Calvin cycle function like?

Functions like a sugar factory within a chloroplast.

How do glycolysis and the citric acid cycle generate ATP?

Generate a small amount of ATP directly and much more ATP indirectly, via reactions that transfer electrons from fuel molecules to a molecule called NAD+.

What determines features?

Genes, Environment, and some by both.

Genotype

Genetic make up.

What do Geneticists do?

Geneticists who study people obviously cannot control the mating of their research participants but instead analyze the results of mating that have already occurred First geneticists collects as much information as possible about a family's history for a trait. Then the researcher assembles this information into a family tree.

What is the latin meaning for species?

Kind or appearance.

What are some examples of polyploids that we have grown for food?

Oats, Potatoes, Bananas, Strawberries, Peanuts, Apples, Sugarcane, and Wheat.

When does mass extinctions occur?

Occur when there are big changes.

Hybrids

Offspring of two different purebred varieties .

How does Sexual reproduction convey an evolutionary advantage?

Producing offspring of varied genetic makeup or reducing the incidence of harmful genes more rapidly.

What has the diversity of life evolved through?

Speciation.

What would convince anyone that environment influences character (includes effects of personal choice and affects a person's traits)?

Spending time with identical twins.

What does the Punnett square highlight?

The four possible combinations of gametes and the resulting four possible offspring in the F2 generation. Each square represents an equally probable product of fertilization.

What can Cancer cells form?

Tumors.

How many traits did each of the characters Mendel studied occur in?

Two distinct traits.

Three-domain system

Two domains of prokaryotes (bacteria and archaea) and one domain of eukaryotes (eukarya).

What is produced of the combination of mitosis and cytokinesis?

Two genetically identical daughter cells.

Centromere

Two sister chromatids are joined together tighly at a narrow "waist".

Huntington's disease

Uncontrollable movements; Cognitive impairments; Occurs in middle age.

What can we predict using Mendel's laws relative to recessive disorders?

We can predict the fraction of affected offspring that is likely to result from a marriage between two carriers.

How long do all cells live for?

Not all cells live for the same amount of time.

What should the cell cycle be thought as?

"lifetime" of a cell, from its "birth" to its own reproduction. Once it reproduces, its life is over.

Wild-Type traits

(those seen most often in nature) are not necessarily specified by dominant alleles.

What can a technician do to produce a karyotype?

- Break open a human cell in metaphase of mitosis - Stain the chromosomes with dyes - Take a picture with the aid of a microscope, and - Arrange the chromosomes in matching pairs by size.

How do modern technologies offer several ways to identify about 30 treatable genetic diseases before they appear?

- Several technologies exist for detecting genetic disorder during pregnancy. - Genetic testing before birth usually requires the collection of fetal cells. Once the cells are obtained, they can be screened for genetic diseases - In amniocentesis, a physician uses a needed to extract the fluid that bathes the developing fetus - In chronic villus sampling, a physician inserts a narrow, flexible tube through the mother's vagina and into her cervix, removing some placental tissue - Newer genetic screening procedures involve isolating tiny amount of fetal cells or DNA released into the mother's bloodstream.

What are are the three subphrases that make up Interphase in the cell cycle?

1. G1 phase: "First gap" 2. S phase: "Synthesis" of DNA (DNA replication) 3. G2 phase: "Second gap".

What are the three main stages of the many chemical reactions that make up cellular respiration?

1. Glycolysis 2. Citric acid cycle 3. Electron transport chain.

What are the two distinct forms of polyploid speciation have been observed in sympatric speciation?

1. In one form, polyploidy arises from a single parent species. A failure of cell division might double the chromosome number from the original diploid number (2n) to tetraploid (4n) 2. A second form of polyploid speciation can occur when two different species interbreed and produce hybrid offspring.

What are the two stages of photosynthesis that are connected by energy-carrying and electron-carrying molecules?

1. LIGHT REACTIONS in which chlorophyll in the thylakoid membranes absorbs solar energy, which is then converted to the chemical energy of ATP and NADPH and 2. CALVIN CYCLE which uses the products of the light reactions to power the production of sugar from carbon dioxide.

What are the two overlapping process included in the mitotic phase of the cell cycle?

1. Mitosis 2. Cytokinesis

What are the two kinds of cell division that are involved in the lives of sexually reproducing organisms?

1. Mitosis for growth and maintenance and 2. Meiosis for reproduction.

What are the generations of Hybrids?

1. P generation - parental plants 2. F1 generation - hybrid offspring 3. F2 generation - cross of F1.

What are some examples of photosynthetic autotrophs that shows diversity?

1. Plants (mostly land plants) - Forest plants 2. Photosynthetic protists (aquatic) - Kelp, a large multicellular algae 3. Photosynthetic Bacteria (aquatic) - Micrograph of cyanobacteria.

How are Meiosis and Mitosis different?

1. The number of chromosomes during Meiosis is cut in half 2. An exchange of genetic material (pieces of chromosomes) between homologous chromosomes. This exchange, called crossing-over, occurs during the first phase of meiosis.

What does our indelible footprint include?

1. The transport of organisms far from their natural homes 2. The prevalence of agriculture and domesticated animals 3. The existence of manufactured materials such as plastics and concrete 4. Radioactivity from testing nuclear weapons 5. Climate-altering emissions from burning fossil fuels.

What percentage of heat transfers from one trophic to the next?

10%.

Linked genes are not _________ independently assorted.

100%.

How many possible chromosome combinations are there for a human?

2 ^ 23 which is about 8 million.

What percentage of Oxygen is in the air we breathe?

21%.

What percentage of Oxygen is in the air at the top of Mount Everest?

21%. It is hard to breathe due to the difference in pressure due to altitude, there is no change in Oxygen level.

Autosomes

22 pairs of matching chromosomes.

How many chromosomes are in humans?

23 pairs of chromosomes, 46 total chromosomes.

What does the input of glucose + 6 Oxygen lead to relative to cellular respiration?

6 Carbon dioxide + 6 water + 32 ATP molecules.

What is the overview of the process of photosynthesis?

6 carbon dioxide + 6 water leads to photosynthesis arrow of light energy and then the product of glucose and 6 oxygen gas.

What is the possible number of chromosomes combinations that can occur in the zygote of a man and a woman?

64 trillion combinations.

How many times ( at least) were dogs rebreed from wolves?

7 times.

What did a 2010 study of dogs indicate?

A 2010 study indicated that small dogs were first bred within early agricultural settlements of the Middle East around 12,000 years ago. Continues over millennia, such genetic tinkering has resulted in a diverse array of dog body types and behaviors.

What happens during Interphase relative to the cell cycle?

A cell performs its normal functions, doubles everything in its cytoplasm, and grows in size.

What do many phenotypic characters result from?

A combination of heredity and environment.

Monohybrid cross

A cross between two individuals that are heterozygous for one character.

Dihybrid cross

A cross between two organisms that are each heterogenous for two characters.

What is the overview (summary) of cellular respiration?

A molecule of glucose is split into two molecules of a compound called pyruvic acid, located in the cytoplasm. The the citric acid cycle completes the breakdown of glucose all the way to carbon dioxide, which is then released as a waste product. The enzymes for the citric acid cycle are dissolved in the fluid within the mitochondria.

What is a result from a sex-linked recessive allele?

A number of human conditions, including red-green colorblindness, hemophilia, and a type of muscular dystrophy.

Down Syndrome

A person with Trisomy 21 has this condition.

Chlorophyll

A pigment (light-absorbing molecule) in the chloroplasts that plays a central role in converting solar energy to chemical energy.

How much glucose do brain cells burn each day?

A quarter pound.

Electron transport chain

A series of electron carrier molecules.

Law of Segregation

A sperm or egg carries only one allele for each inherited character because the two alleles for a character segregate (separate) from each other during the production of gametes.

What is Mendel's fourth hypothesis?

A sperm or egg carries only one allele for each inherited character because the two alleles for a character segregate (separate) from each other during the production of gametes. When sperm and egg unite at fertilization, each contributes its alleles, restoring the paired condition in the offspring.

Stroma

A thick fluid.

How can growth of cancer and metastasis of a malignant tumor in the breast occur?

A tumor grows from a single cell of cancer. Cancer cells invade neighboring tissues in the breast. Metastasis occurs when cancer cells spread through lymph and blood vessels to other parts of the body.

What is an example of a human disorder caused by dominant alleles? How does it function?

Achondroplasia which is a form of dwarfism in which the head and torso develop normally but the arms and legs are short. The homozygous dominant genotype (AA) causes death of the embryo, and therefore only heterozygotes (Aa), individuals with a single copy of the defective allele, have this disorder. This also means that a person with achondroplasia has a 50% chance of passing the condition on to any children.

Cellular respiration

Aerobic harvesting of chemical energy from organic fuel molecules, the main way that chemical energy is harvested from food and converted to ATP, and an aerobic process.

Maria has type O blood, ad her sister has type AB blood. What are the genotypes of the girls' parents?

Ai and Bi.

Diploid

All body cells contain pairs of homologous chromosomes.

What are the ways in which species can form?

Allopatric speciation and Sympatric speciation.

How is the mechanism of ATP production during the light reactions is very similar to the mechanism we saw in cellular respiration?

An electron transport chain pumps hydrogen ions across a membrane and ATP synthases use the energy stored by the H+ gradient to make ATP.

What happens when a pigment molecule absorbs a photon and then one of the pigment's electrons gains energy and is no said to be "excited"?

An excited electron usually loses its excess energy and falls back to its ground state. Most pigments released heat energy as their light excited electrons fall back to their ground state.

Heterozygous

An organism that has two different alleles for a gene.

Homozygous

An organism that has two identical alleles for a gene.

Is the process of making wine aerobic or anaerobic?

Anaerobic.

Reproductive barrier

Anything that prevents individuals of closely related species from interbreeding.

Which of the following Bacteria, Archaea, and Eukarya are most similar?

Archaea and Eukarya.

What are the advantages of some of these newer noninvasive technologies relative to genetic testing?

Are more accurate, can be performed earlier, and are safer than other tests. Thus, they are gradually replacing more invasive screening methods.

When does a new species arise in sympatric speciation?

Arises within the same geographic area as its parent species.

What are dogs a good example of?

Artificial selection.

Do human activities facilitate speciation?

As humans travel the world, we often transport plants, animals, and other organisms to regions beyond their natural range. These activities create opportunities for hybridization that would not otherwise exist. Fifty years after the introduction of the plant goatsbeard (a weedy member of the daisy family) to the US, a botanist discovered that hybridization had produced two new species.

How have researchers documented at least two dozen cases in which populations are diverging?

As they use different resources or breed in different habitats.

What is Mitosis responsible for?

Asexual reproduction and growth and maintenance of multicellular organisms.

What is a human driven change that has affected other species?

Baby turtles hatch on the beach and go to the light (ocean) but due to human life, they sometimes go to lights of towns instead which kills them.

Why can't a male be a carrier in color blindness?

Because only one X and can either be dominant or recessive.

Why did Mendel chose to study garden peas?

Because they were easy to grow and came in many readily distinguishable varieties.

What occurs during Stage 2: Citric acid cycle of cellular respiration?

Before pyruvic can be used by citric acid cycle, it must be converted to a form the citric acid cycle can use 1. each pyruvic acid loses a carbon as carbon dioxide. The remaining fuel molecules, with only two carbons left, as caked acetic acid 2. Electrons are stripped from these molecules and transferred to NAD+, forming NADH 3. Each acetic acid is attached to coenzyme A (CoA) to form acetyl CoA 4. the citric acid cycle finishes extracting the energy of sugar by dismantling the acetic acid molecules all the way down to carbon dioxide Acetic acid joins a 4-Carbon acceptor molecule to form a six-carbon product called citric acid For every acetic acid molecule that enters the cycle as fuel, two carbon dioxide molecules eventually exit as a waste product. Along the way, citric acid cycle harvests energy from the fuel 5. Some of the energy is used to produce ATP directly 6. However, the cycle captures much more energy in the form of NADH and a second, closely related electron carrier called FADH2 7. All the carbon atoms the entered the cycle as fuel are accounted for as carbon dioxide exhaust, and the 4-Carbon acceptor molecule is recycled.

When does the abnormal behavior of cancer cells begin?

Begins when a single cell undergoes genetic changes (mutations) in one or more genes that encodes for proteins in the cell cycle control system - These changes cause the cell to grow abnormally.

What are the stages of Earth?

Begins with Pre-cambrian (Like 3/4 of earth's history), Paleozoic, Mesozoic, and Cenozoic (least amount of time).

What are the different types of tumors?

Benign and Malignant.

What do genetics distinguish between?

Between an organism's physical appearance and genetic makeup.

What is a side-effect of Hemophilia?

Bleed excessively when injured because they have inherited an abnormal allele for a factor involved in blood clotting. The most serious affected individuals may bleed to death after relatively minor bruises or cuts.

What is misleading about the following statement? "Plants perform photosynthesis, whereas animals perform cellular respiration."

Both plants and animals undergo cellular respiration.

What have human-driven changes in the environment brung about?

Bring about evolutionary change in populations of organisms, including , pesticide-resistant insects and antibiotic-resistant bacteria.

Give an example of how phylogeny can have practical applications?

By constructing a phylogeny of maize, researchers have identified two species of wild grasses that may be maize's closest living relatives. The genomes of these plants may harbor alleles that offer disease resistance or other useful traits that could be transferred into cultivated maize, insurance against future disease outbreaks or other environmental changes that might threaten corn crops.

How did Mendel decide his Law of Segregation?

By following one character through two generations. Monohybrid cross and Dihybrid cross.

How has continental drift had a tremendous impact on the evolution of life's diversity?

By reshaping the physical features of the planet and altering the environments in which organisms live.

What can Mendel's laws be applied to?

Can be applied to the inheritance of human traits that are generally agreed to be determined by a single gene, such as freckles or a widow's peak hairline.

What can the electricity that photovoltaic (PV) solar panels produce from sunlight can be used for?

Can be used directly, Stored in batteries, or Transferred to the national electric grid.

What can nondisjunction in Meiosis lead to?

Can lead to abnormal numbers of sex chromosomes, X and Y.

What happens when there is an error in the process of Meiosis?

Can result in genetic abnormalities that range from mild to severe to fatal.

Malignant tumor

Can spread into neighboring tissues and other parts of the body, forming new tumors, and can interrupt organ function.

What chemical ingredients do plants require from the environment to synthesize their own food?

Carbon dioxide + water + sunlight generates glucose (energy).

What are the waste products of cellular respiration?

Carbon dioxide and Water.

What are the chemical ingredients for photosynthesis and how do they act?

Carbon dioxide and Water. Carbon dioxide passes from the air into a plant via tiny pore. Water is absorbed from the soil by the plant's roots.

What is red-green colorblindness is a common sex-linked disorder caused by?

Caused by a malfunction of light-sensitive cells in the eyes. Mostly males are affected, but heterozygous females have some defects too.

What directs the sequential events of the cell cycle?

Cell cycle control system.

Why is cell division important?

Cells do not live forever, so they get replaced.

Microevolutionary change

Changes we can see in allele frequencies.

What are some of the noticeable characteristics of down syndrome?

Characteristic facial features, Usually have a life span shorter than usual, and exhibit varying degrees of developmental delays.

Where do chloroplasts get their green color from?

Chlorophyll.

What occurs inside leaf cells relative to photosynthesis?

Chloroplasts use light energy to rearrange the atoms of these ingredients to produce sugars, most importantly glucose and other organic molecules.

What are chromosomes made of?

Chromatin.

What occurs in Interphase of Meiosis (Part one)?

Chromosomes duplicate.

What type of chromosomes do gametes arise with when crossing over?

Chromosomes that are partly from the mother and partly from the father. These chromosomes are called "recombinant" because they result from genetic recombination, the production of gene combinations different from those carried by the parental chromosomes.

Relative to reproduction of cells, where does most of the structures contain most the cell's DNA?

Chromosomes.

What undergoes segregation and independent assortment during meiosis and thus account for Mendel's laws?

Chromosomes.

What does cellular respiration consist of and constitute?

Consists of many chemical steps using a specific enzyme to catalyze each reaction, constitutes one of the most important metabolic pathways for nearly every eukaryotic cell, and provides the energy these cells need to maintain the functions of life.

What does the Cell cycle control system consist of?

Consists of specialized proteins within the cell.

What does the Calvin cycle construct?

Constructs an energy-rich sugar molecule called glyceraldehyde 3-phosphate (G3P) using carbon from carbon dioxide, energy from ATP, and high-energy electrons from NADH. The plant cells then use G3P as the raw material to make glucose and other organic compounds.

Sister chromatids

Contain identical genes.

What does each eukaryotic chromosome contain?

Contains one very long DNA molecule, typically bearing thousands of genes.

What does cellular respiration use Oxygen to do?

Convert the energy stored in the chemical bonds of sugars to another source of chemical energy called adenosine triphosphate (ATP).

What is there a positive correlation to in relation to down syndrome?

Correlation between the risk of down syndrome increases with the age of the mother. The fetuses of pregnant women age 35 and older are therefore candidates for chromosomal prenatal screenings.

What is the most lethal genetic disease in the USA?

Cystic Fibrosis. About 1/31 Americans or 10.5 million Americans are carriers.

Cytokinesis

Cytoplasm (along with all the organelles) is divided into two.

Biological species concept

Defines species as a group of populations whose members have the potential to interbreed with one another in nature to produce fertile offspring (offspring that can reproduce).

What does the number of chromosomes in a eukaryotic cell depend on?

Depends on the species.

What do biologists use phylogenetic trees to do?

Depict hypotheses about the evolutionary history of species and reflect the hierarchal classification of groups nested with more inclusive groups.

What are the phases of the cell cycle?

Interphase and mitotic phase.

Cancer

Disease of the cell cycle.

What did Linnaeus do?

Divided all known forms of life between the plant and animal kingdoms. This two kingdom system prevailed in biology for over 200 years. In the mid 1900s, the two-kingdom system was replaced by a five-kingdom system that placed all prokaryotes in one kingdom and divided the eukaryotes among four other kingdoms.

Geographic Time Scale

Divides Earth'd history into a consistent sequence of geologic periods.

What does Glycolysis not require?

Does not require Oxygen but does produce two ATP molecules for each glucose molecule broken down to pyruvic acid.

What does a dominant trait imply?

Dominance means that a heterozygous genotype results in the dominant phenotype. It does not imply that it is either normal or more common than a recessive genotype.

What is the most common chromosome number abnormality?

Down syndrome.

What is the most serious birth defect in the United States?

Down syndrome.

What does a parent cell do before it splits into two?

Duplicates its chromosomes.

When can nondisjunction occur?

During Meiosis I or II.

What occurs in Stage 3: Electron transport of cellular respiration?

During cellular respiration, the electrons gathered from food molecules gradually "fall", losing energy at each step. Electrons are transferred from glucose in food molecules NAD+. This electron transfer converts NAD+ to NADH. Then NADH releases two electrons that enter an electron transport chain and with each exchange, the electron gives up a bit of energy The molecules of electron transport chains are built into the inner membranes of mitochondria. Because these membranes are highly folded, their large surface area can accommodate thousands of copies of the electron transport chain - a good example of how biological structure fits function. The energy stored by electron transport behaves something like the water behind a dam (this process can only take place in eukaryotes since prokaryotic cells do not have mitochondria Mitochondria have structures that act like turbines. Each of these miniature machines, called an ATP synthase, is constructed from proteins built into the inner mitochondrial membrane, adjacent to the proteins of the electron transport chains.

In what phase does the majority of the eukaryotic cell cycle take place in?

Interphase.

What occurs during Stage 1: Glycolysis of cellular respiration?

During glycolysis a six-carbon glucose molecule is split in half to form two molecules of pyruvic acid. This initial split requires an energy "investment" of two ATP molecules per glucose. The three-carbon molecules then donate high energy electrons to NAD+, forming NADH. Glycolysis also generates four ATP molecules. Glycolysis thus produces a net gain of two molecules of ATP per molecule of glucose.

What is so different about how the gender of turtles and many other reptiles is decided?

During incubation, gender depends on incubation temptation when developing.

Achondroplasia

Dwarfism.

What happens when the sister chromatids are separated?

Each chromatid is considered a full-fledged chromosome and is identical to the original chromosome.

What do the pairs of homologous chromosomes in a human male karyotype look like?

Each pair is the same size and shape except the X and the Y pair.

Gametes

Egg and sperm

What do some pigments emit after absorbing photons?

Emit light as well as heat. The fluorescent light emitted by a low stick is caused by a chemical reaction that excited electrons of a fluorescent dye. The excited electrons quickly fall back down to their ground state, releasing energy in the form of fluorescent light.

What do Mendel's laws enable us to do?

Enable us to deduce the genotypes for most of the people in the pedigree

What can organisms that capture sunlight using photosynthesis also serve as?

Energy sources. Such as plant matter can be burned and plant materials can be used to produce biofuels.

What does all of life require?

Energy.

What occurs when there is a lack of ATP molecules?

Entropy (disorder).

What have biologists begun to recognize the importance of in recent years?

Epigenetic inheritance.

Not all foods are _________.

Equal.

Nondisjunction

Error in Meiosis when the members of a chromosome pair fail to separate at Anaphase, producing gametes with abnormal numbers of chromosomes.

What can wastes from fermentation be?

Ethyl alcohol, lactic acid, or other compounds, depending on the species.

What type of basis does the role of glycolysis in respiration and fermentation have?

Evolutionary basis.

Hypercholesterolemia

Excess cholesterol in blood; Heart disease Is a human trait that is an example of incomplete dominance and is characterized by dangerously high levels of cholesterol in the blood. Heterozygotes have blood cholesterol levels about twice as normal. Homozygotes have about five times the normal amount of blood cholesterol and may have heart attacks as early as age 2.

Cystic Fibrosis

Excess mucus in lungs, digestive tract, liver; Increased susceptibility to infections; Death in early childhood unless treated.

Crossing over

Exchange of corresponding segments between non sister chromatids of homologous chromosomes, which occurs during Prophase I of Meiosis.

What do Mendel's two laws explain?

Explain inheritance in terms of genes that are passed along from generation to generation according to simple rules of probability. These laws are valid for all sexually reproducing organisms.

What does the history of continental mergers and separations explain?

Explains patterns of biogeography.

Incomplete dominance

F1 hybrids have an appearance between the parent phenotypes.

True or False. More complex organisms have more chromosomes.

False.

Pedigree

Family tree.

Who entirely determines the sex of a baby?

Father.

What is when some of your cells can work for short period without Oxygen to harvest food energy?

Fermentation.

Chromatin

Fibers composed of roughly equal amounts of DNA and protein molecules.

What did Mendel find in his inheritance of a single character - Mendel's Law of Segregation?

Figured out that the gene for white flowers did not disappear in the F1 plants but was somehow hidden or masked when the purple flower factor was present. He also deduced that the F1 plants must have carried two factors for the flower-color character, one for purple and one for white. He developed four hypotheses from these results.

What is the main difference between the mechanism of ATP production during light reactions and mechanism we saw in cellular respiration?

Food provides the high energy electrons in cellular respiration, whereas light-excited electrons flow down the transport chain during photosynthesis.

What is Mendel's second hypothesis?

For each inherited character, an organism inherits two alleles, one from each parent Homozygous or heterozygous.

What is the difference in macroevolution and microevolution?

For example, relative to coat of rodents, you can see the color of them based on their allele (micro) while you can't see their color in fossils (macro).

How long have people selected and mated dogs with preferred traits for?

For more than 15,000 years - which leads to the incredible variety of body types and behaviors in dogs today.

When is most of the cell cycle spent?

Interphase.

What does Fermentation rely on?

Glycolysis which is the first stage of cellular respiration.

What do both aerobic and anaerobic respiration start with?

Glycolysis.

What is the universal energy harvesting process of life?

Glycolysis.

What were the results of Hill's research?

Gradually, however, evidence that contradicted Hill's results began to accumulate. The effect that Hill demonstrated did not appear to occur at human body temperature. Further, certain individuals who are unable to accumulate lactic acid have muscles that fatigue more rapidly, the opposite of what is expected. Some research indicated that increased levels of other ions may be to blame. Therefore, the cause of muscle fatigue remains hotly debated.

What does a shorter wavelength of light mean?

Greater the energy of a photon. Shows that the size of wavelengths that come in matter

How is the chloroplast similar to the mitochondria?

Has a double membrane envelope. The inner membrane encloses a compartment filled with the stroma. Suspended in the stroma are interconnected membranous sacs. The thylakoids are concentrated in stacks. The chlorophyll molecules that capture light energy are built into the thylakoid membranes.

Haploid cell

Has only one member of each pair of homologous chromosomes.

What type of chromosomes do different individuals of a single species have?

Have the same number and types of chromosomes.

What is a key factor in the life cycle of humans and all other species that reproduce sexually?

Having two sets of chromosomes, one inherited from each parent.

Consumers

Heterotrophs because they obtain their food by eating plants to by eating animals that have eaten plants.

What did AV Hill do to test what causes muscles to burn?

Hill knew that muscles produce lactic acid under anaerobic conditions. In 1929, Hill developed a technique for electrically stimulating dissected frog muscles in laboratory solution. Hill showed that when lactic acid could not diffuse away from muscle tissue, muscle performance declines. When lactic acid could diffuse away from the muscle tissue, muscle performance improved significantly.

What helped Mendel understand the patterns of inheritance?

His strong background in mathematics. He understood that genetic crosses obey the rules of probability - the same rules that apply when tossing coins, rolling dice, or drawing cards.

How can Homologous structures be similar and different?

Homologous structures in different species may vary in form and function but exhibit fundamental similarities because they evolved from the same structure in a common ancestor. Homologous structures are one of the best sources of information for phylogenetic relationships.

What has had an extraordinary effect on the ecology and geology of Earth?

Humanity.

What is Mendel's third hypothesis?

If an organism has two different alleles for a gene, one allele determines the organism's appearance and is called the dominant allele; The other allele has no noticeable effect on the organism's appearance and is called the recessive allele. Genetics use uppercase italic letters (such as P) to represent dominant alleles and lowercase italic letters (such as p) to represent recessive alleles.

Benign tumor

If the abnormal cells remain at the original site.

What question was answered when Mendel crossed the F1 plants with each other?

If the genes for the two characters were inherited together, then the F1 hybrids would produce only the same two kinds of gametes that they received from their parents, and the F2 generation would show a 3:1 phenotypic ratio If, however, the two seed characters sorted independently, then the F1 generation would produce four gamete genotypes in equal quantities and the F2 generation would have nine genotypes producing four different phenotypes in a ratio of 9:3:3:1.

What does the location of glycolysis within the cell imply?

Implies great antiquity. The pathway does not require any of the membrane-enclosed organelles of the eukaryotic cell, which evolved more than a billion years after the prokaryotic cell.

When do you "repay" when you workout?

In the beginning of a workout, you demand a quick start up so towards the end of the workout, you repay by heavy breathing.

Where can the law of Independent Assortment be seen?

In the inheritance of two characters in Labrador Retrievers.

Polyploidy

In which a species may originate from an accident during cell division that results in an extra set of chromosomes.

Systematics

Includes Taxonomy and focuses on classifying organisms and determining their evolutionary relationships.

Where can the biological species concept cannot be applied in all situations?

Including asexual organisms and fossils.

Carriers

Individuals who have the recessive allele but appear normal.

What is the input and output of the Calvin cycle?

Input: Carbon dioxide, ATP, and NADH Output: Glucose.

What do the specialized proteins inside the Cell cycle control system do?

Integrate information from the environment and from other body cells and send "stop" and "go ahead" signals at certain key points during the cell cycle.

ABO blood groups

Involved three alleles of a single gene Various combinations of these three alleles produce four phenotypes. Therefore, a person's blood type may be A, B, AB, or O. These letters refer to two carbohydrates, designated A and B, that may be found on the surface of red blood cells.

Convergent evolution

Involves superficially similar structures from different evolutionary branches that result from natural selection shaping analogous adaptation.

Macroevolution

Is evolutionary change above the species level and includes the impact of mass extinctions on the diversity of life and the origin of key adaptations such as flight.

Temporal isolation

Isolation because breed at different times of the day or year.

Gametic isolation

Isolation because gametes aren't compatible.

Mechanical isolation

Isolation because they can't fit.

Behavioral Isolation

Isolation due to differences in behavior. Example: Red v. Blue feet.

Habitat isolation

Isolation due to differences in habitat.

How is Meiosis II virtually identical to Mitosis? However..?

It separates sister chromatids. But unlike Mitosis, Meiosis II yields daughter cells with a haploid set of chromosomes.

What is the outcome of producing haploid gametes by meiosis?

Keeps the chromosome number from doubling in every generation.

Albinism

Lack of pigment in skin, hair, and eyes.

What is the result when there is a lack of Pyruvic acid?

Lactic acid (cramps).

Interphase

Lasts for at least 90% of the cell cycle.

Dominant alleles that cause lethal disorder are much ________ common that lethal recessive alleles.

Less.

Photons

Light behaves as waves and discrete packets of energy at fixed quantities of light energy.

Chloroplasts

Light-absorbing organelles, Site of photosynthesis, and Found mostly in the interior cells of leaves.

What does not follow Mendel's law of independent assortment?

Linked genes because they are often inherited as a set.

Who is the father of taxonomy?

Linnaeus.

Tay-Sachs disease

Lipid accumulation in brain cells; Developmental deficiencies; Death in childhood.

Linked genes

Located near each other on the same chromosome and tend to travel together during meiosis and fertilization.

What are the sex chromosomes of males and females that are found in animals, including all mammals?

Male = X and Y Female = X and X.

What kind of tumor does a person have when they have Cancer?

Malignant.

What is critical for safe blood transfusions?

Matching compatible blood groups. If a donor's blood cells have carbohydrate ( A or B) that is foreign to the recipient, then the recipient's immune system produce blood proteins called antibodies that bind to the foreign carbohydrates. These antibodies cause the donor blood cells to clump together, potentially killing the recipient.

Testcross

Mating between an individual of dominant phenotype (but unknown genotype) and a homozygous recessive individual.

What can Epigenetic modifications and and the changes in gene activity that result do?

May be carried on to the next generation. Unlike alterations to the DNA sequence, chemical changes to the chromosome can be revered.

What occurs in Meiosis I (Part Two)?

Meiosis I - Homologous chromosomes separate Prophase I: Homologous chromosomes pair up and exchange segments Metaphase I: Pair of homologous chromosomes line up Anaphase I: Pairs of homologous chromosomes split up Telophase I and Cytokinesis: Two haploid cells form; Chromosomes are still doubled.

When do all events unique to Meiosis occur?

Meiosis I.

What occurs in Meiosis II (Part three)?

Meiosis II - Sister chromatids separate Prophase II: ... Metaphase II: ... Anaphase II: Sister chromatids separate Telophase II and Cytokinesis: Haploid daughter cells forming Result - During another round of cell division, the sister chromatids finally separate; Four haploid daughter cells result, containing single chromosomes.

What was the most important advantage of pea plants as an experimental model?

Mendel could strictly control their reproduction.

How do Mendel's laws stop short of explaining some patterns of genetic inheritance?

Mendel's rules can strictly account for patterns of inheritance are relatively rare for most sexually reproducing organisms. More often, the observed inheritance patterns are more complex.

Alzheimer's disease (one type)

Mental deterioration; Usually strikes late in life.

Sickle-Cell disease

Misshaped red blood cells; Damage to many tissues.

Where does the production of ATP during cellular respiration in plants and animals?

Mitochondria.

What is the difference between Meiosis and Mitosis?

Mitosis - which proves for growth, tissue repair, and asexual reproduction, produces daughter cells that are genetically identical to the parent cell Meiosis - need for sexual reproduction, yields genetically unique haploid daughter cells - cells with only one member of each homologous chromosome pair.

Where are most genes located in eukaryotic cells?

Most genes are located on chromosomes in the cell nucleus, except for genes on small DNA molecules found on mitochondria and chloroplasts.

Continental drift

Movements in the mantle cause the plates to move. The boundaries of some plates are hotspots of geologic activity. Earthquakes signal that two plates are scraping past or colliding with each other.

How have we been able to observe speciation in progress with the use of fossils?

Much of the evidence for evolution comes from the fossil record. In one of 84 groups of plants and animals, the time for speciation ranged from 4,000 to 40 million years. The cumulative effects of multiply speciations, as well as extinctions, have shaped the dramatic changes documented in the fossil record.

What is the human life cycle relative to cells?

Multicellular diploid adults (2n = 46) go through meiosis (sex) where the haploid gametes (n = 23), n egg cell and n sperm cell go through fertilization to crate 2n diploid gamete (2n = 46) which leads to mitosis and development. Repeat.

What must a plant or animal control to grow and maintain its tissues normally?

Must be able to control the timing of cell division.

What must be present to harvest food energy during glycolysis relative to fermentation in human muscle cells?

NAD+ must be present to receive electrons. There is no problem under aerobic conditions, because the cell regenerates NAD+ when NADH drops its electron cargo down electron transport chains to Oxygen. However, this recycling of NAD+ cannot occur under anaerobic conditions because there is no Oxygen. Instead, NADH disposes of electrons by adding them to the pyruvic acid produced by glycolysis, producing a waste product called lactic acid.

Are the offspring of sexual reproduction identical to the parents and siblings?

No.

What is the main reason for pregnancy loss?

Nondisjunction. It appears to be involved in 10-30% of human conceptions.

Taxonomy

Naming and classification of species.

What is a very old and hotly contested issue relative to how characters are influences by genes or by the environment?

Nature or Nurture.

NAD+

Nicotinamide adenine dinucleotide.

What is an example of the allele that causes Huntington's disease ( a degeneration of the nervous system that usually does not begin until the middle age)?

Once the deterioration of the nervous system begins, it is irreversible and inevitably fatal. Because the allele for it is dominant, any child born to a parent with the allele has a 50% chance of inheriting the allele and the disorder.

What was the inheritance pattern that Mendel found in each of the seven characters he studied?

One of two parental traits disappeared in the F1 generation, only to reappear in 1/4 of the F2 offspring.

Relative to genetics, what in general is inherited?

Only genetic influences are inherited and any effects of the environment are not usually passed to the next generation.

Postzygotic barriers

Operate if interspecies mating occurs and hybrid zygotes form (zygote forms but weak or sterile).

Cell Cycle

Ordered sequence of events that extend from the time a cell is first formed from a dividing parent cell to its own division into two cells.

What do the protein molecules help organize relative to eukaryotic chromosomes?

Organize the chromatin and help control the activity of its genes.

Heterotrophs

Other-feeders; Include humans and other animals and cannot make organic molecules from inorganic ones.

What is a by-product of photosynthesis?

Oxygen gas.

What is the underlying mechanism explained by Mendel's Law of Segregation?

Pairs of alleles segregate during gamete formation and the fusion of gametes at fertilization creates allele pairs again.

How is a female shark in Queensland, Australia able to reproduce a daughter without fertilization by a male? Where do the genes come from?

Parthenogenesis. Genes solely come from the mother.

What major theme is illustrated by the below action? "Most ecosystems depend on the process of photosynthesis to convert the energy of sunlight into high-energy molecules, which then provide fuel for other organisms."

Pathways that transform energy and matter.

What happened 15,000 years ago in East Asia?

People began to cohabit with ancestral canines that were predecessors of both modern wolves and dogs. As people moved into permanent, geographically isolated settlements, populations of canines were separated and eventually became inbred.

What conversion do all animals depend for food and more?

Photosynthesis.

What do most ecosystems depend entirely on for food?

Photosynthesis.

What are hypotheses bout evolutionary history?

Phylogenetic trees.

Phenotype

Physical appearance.

Producers

Plants and other autotrophs.

Photoautotrophs

Plants and other organisms generate their own organic matter by photosynthesis and are the producers for most ecosystems.

Photosynthesis conversion of energy

Plants convert the energy of sunlight to the chemical energy of sugars and other organic molecules.

What usually makes more organic molecules than they need for fuel?

Plants.

What are the factors that can reduce gene flow un sympatric populations?

Polyploidy, Habitat complexity, and Sexual selection.

What are the positives and negatives of asexual reproduction in comparison to sexual reproduction?

Positive - Eliminates the need to expend energy forming gametes and finding a partner Negative - Confers an evolutionary advantage when organisms are superbly suited to a stable environment.

Prezygotic barriers

Prevent mating or fertilization between species (zygote never forms).

Fertilization

Process in which a haploid sperm fuses with a haploid egg during the human life cycle.

Speciation

Process in which one species splits into two or more species.

Meiosis

Process of cell division that produces haploid gametes in diploid organisms.

Sexual reproduction

Produce offspring that contain a unique combination of genes from the parents and depends on the cellular processes of meiosis and fertilization.

What has the irreversibility of these charges has led some scientists to propose?

Propose that a new epoch in Earth's history has begun: the Anthropocene.

Why is the number of kingdoms in the domain eukarya divided?

Protists are a disaster and all over the place.

What is the result of photosynthetic surplus relative to plants?

Provides material for the plant to grow or can be stored, as starch in potatoes, for example.

Where is parthenogenesis rare?

Rare among vertebraes (animals with backbones), although it has been documented in about 70 species as diverse as lizards, domesticated birds, and frogs.

What are most genetic disorder (dominant or recessive) that cause medical disorders?

Recessive.

What are some autosomal disorders in people?

Recessive: Albinism, Cystic Fibrosis, Phenylketonuria (PKU), Sickle-Cell disease, and Tay-Sachs disease Dominant: Achondroplasia, Alzheimer's disease (one type), Huntington's disease, and Hypercholesterolemia.

What are the types of post zygotic barriers?

Reduced Hybrid Viability, Reduced Hybrid Fertility, and Hybrid Breakdown.

What does carbon fixation reduce?

Reduces the concentration of carbon dioxide in the atmosphere.

What was the result of the plate movements forming the supercontinent about 250 million years ago?

Reducing the total amount of shoreline, Deepening ocean basins, and Lowering sea levels.

Asexual reproduction

Single celled organisms reproduce by dividing in half, producing offspring that are genetic replicas of the parent cell. There are no fertilization of an egg by a sperm. The resulting cells are a clone.

What kind of energy is used relative to solar power?

Renewable.

What does cell division do that is important?

Replaces damaged or lost cells, Permits growth, and Allows for reproduction.

Aerobic

Requires Oxygen.

What is the specifics of sexual reproduction?

Requires fertilization of an egg by a sperm. The production of gametes involves a special type of cell division called meiosis which occurs only in reproductive organs.

Homologous chromosomes

Resemble each other in length and centromere position and carry genes controlling the same inherited characteristics.

What are the results of cellular respiration?

Respiration is a versatile metabolic furnace that can "burn" many other kinds of food molecules. The interplay between these pathways provides a clear example of the theme of system interactions; in this case, all of these interactions contribute to maintaining a balanced metabolism.

Zygote

Resulting egg from fertilization which is diploid and has two sets of chromosomes, one set of chromosomes from each parent.

In sympatric speciation of a plant, why is it important to be fertile and viable?

So it can reproduce.

What is a typical human body cell relative to homologous chromosomes?

Somatic cell - has 46 chromosomes.

Genetics

Scientific study of heredity.

What does an unusual number of sex chromosomes tend to upset?

Seem to upset the genetic balance less than usual number of autosomes.

Why do leaves appear green to us?

Selective absorption of light by leaves. The light of that color is poorly absorbed by chloroplasts and is thus reflected or transmitted toward the observer.

Autotrophs

Self-feeders; Organisms that make all their own organic matter from inorganic ingredients: carbon dioxide from the air and water and minerals from the soil.

How did the continental drift affect Australia?

Separated Australia from other landmasses. Australia and its neighboring islands are home to more than 200 species of marsupials, most of which are found nowhere else in the world.

Life cycle of a multicellular organism

Sequence of generation-to-generation stages, from fertilization to the production of its own offspring.

Hemophilia

Sex-linked recessive trait with a long, well-documented history.

What is Meiosis (summed up)?

Sexual reproduction.

What does the overall equation for cellular respiration show?

Shows that the atoms of the reactant molecules glucose and oxygen are rearranged to form the products carbon dioxide and water.

What does a Lab Retriever test cross show?

Shows the offspring that could result from such a mating.

What does the Anthropocene signaled a significant shift in?

Significant shift in the geologic record that includes a high rate of extinction and accelerating change to Earth.

Analogy

Similarity due to convergence, not homology.

Chromosome theory of inheritance

States that genes are located at specific positions (loci) on chromosomes during meiosis and fertilization accounts for inheritance patterns.

Rule of Multiplication

States that the probability of a compound event is the product of the separate probabilities of the independent events.

Where is the chemical energy produced via photosynthesis stored?

Stored in the bonds of sugar molecules.

What does the fact that glycolysis occurs in almost all organisms suggest?

Suggest that it evolved very early in ancestors common to all the domains of life.

What hypothesis did Mendel's dihybrid cross support?

Supported the hypothesis that each pair of alleles segregates independent of the other pairs during gamete formation. Thus, the inheritance of one character has no effect on the inheritance of another.

Thylakoids

Suspended in the stroma are interconnected membranous sacs.

What are the types of prezygotic barriers?

Temporal Isolation, Habitat Isolation, Behavioral Isolation, Mechanical Isolation, and Gametic Isolation.

What does Cellular respiration require?

That a cell exchange two gases with its surroundings. The cell takes in Oxygen in the form of gas and it gets rid of waste as carbon dioxide.

What does the fact that nearly all organisms can trace their source of energy back to the sun clearly illustrate?

That the ability to transform energy and matter is vital to the existence of life on earth.

Relative to duplicating chromosomes, what happens before a cell begins the division process?

The DNA molecule of each chromosome is copied through the process of DNA replication and new histone protein molecules attach as needed.

What does reproduction result in?

The birth of new organisms but more commonly involves the production of new cells.

What has spread Hemophilia?

The former practice of strengthening international alliances by marriage effectively spreads hemophilia through the royal families of several nations.

What do both Meiosis and Mitosis have in common?

The chromosomes duplicate only once, in the preceding interphase.

Theory of Plate Tectonics

The continents and seafloor from a thin outer layer of solid rock, called the crust, divided into giant, irregularly shaped plates that float atop the mantle, a mass of hot, viscous material.

What happens if you work even harder and exceed your aerobic capacity?

The demand for Oxygen in your muscles will outstrip your body's ability to deliver it , Metabolism then becomes anaerobic, and Your muscle cells switch to an "emergency mode" in which they break down glucose very inefficiently and produce lactic acid as a by-product.

NADH

The electron transfer forms this molecules which acts as a shuttle carrying high-energy electrons from one area of the cell to another.

Mendel's Law of Independent Assortment?

The inheritance of one character has no effect on the inheritance of another.

Allopatric speciation

The initial block to gene flow is a geographic barrier that physically isolates the splinter population.

Carbon Fixation

The initial incorporation of carbon from the atmosphere into organic compounds.

Aerobic capacity

The maximum rate at which Oxygen can be taken in and used by your muscle cells and therefore the most strenuous exercise that your body can maintain aerobically.

Mitosis

The nucleus and its contents divide evenly into two daughter nuclei.

What can happen if individuals with down syndrome are properly cared for?

They can live to middle age or beyond and many are socially adept, live independently, and hold jobs.

How is a marine iguana a unique species?

They dive into the ocean to feed on fungi.

What makes Cancer cells so harmful?

They do not respond normally to the cell cycle control system, divide excessively, and may invade other tissues of the body.

Parthenogenesis

The production of offspring by a female without involvement of a male.

What is the limiting factor for most endurance athletes in their performance?

The rate at which Oxygen is provided to working muscles.

What should be noticed in the overall equation of photosynthesis?

The reactants for photosynthesis (carbon dioxide and water) are the same as the waste products of cellular respiration and that photosynthesis produces what respiration uses (glucose and oxygen) In other words, photosynthesis has the products and reactants flipped oppositely from cellular respiration.

What is a good example of how interactions between biological components at many different levels affects all life on Earth?

The relationship between photosynthesis, carbon fixation, and global climate.

What is the result of cell division relative to duplicating chromosomes?

The result is that each chromosome consists of two copies called sister chromatids.

Metastasis

The spread of cancer cells beyond their original site.

Biogeography

The study of the past and present distribution of organisms.

Where does most of energy originate from in almost all ecosystems?

The sun.

Epigenetic inheritance

The transmission of traits by mechanisms not directly involving DNA sequence.

What is Mendel's first hypothesis?

There are alternative versions of genes that account for variations in inherited characters. Alternative versions are called alleles.

Trisomy 21

There are three number 21 chromosomes, making 47 total chromosomes (as opposed to 46).

What do chromosomes exist as most of the time relative to eukaryotic chromosomes?

Thin fibers that are much longer than the nucleus they are stored in.

Stolan

Thing that connects a large plant to the part of the plant that grew off it to make its own plant.

Electron transport

Third stage of cellular respiration in which electrons captured from food by NADH are stripped of their energy a little bit at a time until they are finally combined with Oxygen to form water. The proteins and other molecules that make up electron transport chains are embedded within the inner membrane of the mitochondria. Electron transport from NADH to Oxygen releases the energy your cells use to make most of their ATP.

Grana

Thylakoids are concentrated in stacks.

Anthropocene

Time of environmental change on an epic scale. Consequently, habitats affected by human impacts are natural laboratories for studying evolutionary adaptation. Some organisms have become resistant to toxic pollutants from industrial processes. Urban crested anoles in Puerto Rico have more sticky scales, an adaptation to slippery surfaces such as concrete and metal. Urban blackbirds sing at a higher pitch, an adaptation that enables them to be heard over traffic noise.

Stomata

Tiny pores in leaves where carbon dioxide enters and oxygen exits.

What is the main function of cellular respiration?

To generate ATP for cellular work. The process can produce around 32 ATP molecules for each glucose molecule consumed. This is the product if it exactly goes through these steps.

In Mendel's many experiments, what did he track?

Tracked the inheritance of characters, such as flower color, that occur as two alternative traits. Results led him to formulate several hypotheses about inheritance.

What do all living organisms depend on?

Transformations of energy and matter.

Heredity

Transmission of traits from one generation to the next.

What kind of inheritance patterns do sex-linked genes exhibit?

Unusual patterns of inheritance.

Photosynthesis

Used by plants, algae (protists), and certain bacteria, Transform light energy into chemical energy, Uses Carbon Dioxide and water as starting materials, and Releases Oxygen gas as a by-product.

What did ancient prokaryotes use glycolysis to make between 3.5 and 2.7 billion years ago before significant levels were present in Earth's atmosphere?

Used glycolysis to make ATP and generated ATP exclusively from glycolysis.

Trait

Variant of character.

What occurred to form the speciation in the galapagos?

Volcanic islands, such as the Galapagos and Hawaiian island chains, are initially devoid of life. Overtime, colonists arrive via ocean currents or winds. In their new environment, these populations may diverge significantly from their distant parent populations. In addition, islands that have physical diverse habitats and that are far enough apart to permit populations to evolve in isolation but close enough to allow occasional dispersals to occur are often the sites of multiple speciation events. The Galapagos islands are one of the world's great showcases of speciation. For example, the islands have fourteen species of closely related finches. These birds share many finch-like traits, but they differ in their feeding habits, their habitats, and their beaks, which are specialized for what they eat. The distinctive beaks adapted for the specific diets of the different species of finches are an example of the correlation between structure and function.

Cell division

When a cell undergoes reproduction, two daughter cells are produced that are genetically identical to each other and the parent cell.

What is a key event in the origin of a species?

When a population is somehow cut off from other populations of the parent species.

How does Meiosis contribute to genetic variety?

When aligned during Metaphase I of meiosis, the side-by-side orientation of each homologous pair of chromosomes is a matter of chance and For a species with more than two pairs of chromosomes, every chromosomes pair orients independently of all the others at Metaphase I.

When did our understanding of canine evolution took a big leap forward?

When researchers sequenced the complete genome. Using the genome sequence and other data, canine geneticists produced an evolutionary tree based on a genetic analysis of 85 breeds. The formulation of an evolutionary tree for the domestic dog shows that new technologies can provide important insights into genetic and evolutionary questions about life on Earth.

What happens when a cell divides relative to duplicating chromosomes?

When the cell divides, the sister chromatids of a duplicated chromosome separate from each other.

Reduced Hybrid Viability

When two different species mate, then the offspring (F1) is weaker than both its parents.

Hybrid Breakdown

When two different species mate, they create a hybrid offspring. When this offspring mates back with the parent species, this offspring (F2) is weak

What is an example of when the demand for Oxygen in your muscles will outstrip the body's ability to deliver it?

When you sprint the first mile of a 5K then you're dead for the rest.

What is an inherited human trait thought to be controlled primarily by a single gene?

Widow's peak (dominant) and straight hairline (recessive).

Relative to allopatric isolation, when does speciation occur?

With the evolution of reproductive barriers (reproductive isolation) between the isolated population and its parent population. Even if the two populations should come back into contact at some later time, the reproductive barriers will keep them as separate species. (Think of fish in a lake that splits into two).

Sympatric speciation

Without geographic isolation (such as sexual selection).

Anaerobic

Without oxygen.

Sex Chromosomes

X X (female) or X Y (male) for mammals.

Where are most sex-linked genes found?

X chromosome.

What are some organisms that can survive with or without oxygen?

Yeast and some other organisms.