2ND SEMESTER FINAL REVIEW

How is a theory different than an hypothesis?

A hypothesis is a “guess” about what might happen in an experiment based on observations.

A theory is a “broad” explanation of a phenomena that has been scientifically tested and supported.

An example of a hypothesis could be: If a plant is left in a dark closet for a week, then it will die.

If you did indeed perform this experiment and the plant died, then repeated the same experiment several times with the same result, you could form a theory that plants placed in dark closets for a week will die. Here’s the question though—did you prove without a doubt that all plants will always die after a week in a closet?

So, how is a theory different than a law, such as the Law of Gravity?

In Biology, what does evolution mean?

In Biology, evolution means that a species will evolve over time in order to insure continuance of that species.

Can individuals evolve?

Give an example of artificial selection as opposed to natural selection.

An example of natural selection are the various beak sizes of the finches that live in the Galapagos Islands. Short beaks can crack nuts and long beaks can reach into deep places to get insects.

Artificial selection occurs when a species is bred for certain traits by human beings—generally to benefit the human population. Dachshunds were bred to scent, chase and flush out burrowing animals.

What evidence does this give about the Earth?

That Earth is very old, about 4.54 billion years old….

What component drives changes in species and thus

Natural Selection?

Genetic Variation in Populations

What does biogeography mean?

Bio means life. Geography means

location.

Biogeography means the location of organisms on Earth.

What is the study of developmental biology?

Species that are closely related will show similarities in embryos.

What is a fossil?

Traces of organisms that once lived on Earth.

What is the difference between macro and microevolution?

Microevolution is basically changes in allele frequencies within populations.

Macroevolution is evolutionary change that forms a new species.

Which picture represents each type of evolution?

What do homologous structures indicate?

The organisms have a common ancestor.

The organisms would show similarities in the nucleotides of their DNA.

What is the difference between gradualism and punctuated equilibrium?

Gradualism takes place over a long period of time while punctuated equilibrium

happens in “spurts”.

What are the levels of classification in order from largest to smallest?

1. Domain: There are how many? Three: Bacteria, Archae and Eukarya 2. Kingdom 3. Phylum 4. Class 5. Order 6. Family 7. Genus 8. Species

Do body cell mutations lead to genetic variation?

No, only sex cells will pass a mutation on to offspring.

What can cause reproductive isolation in a species?

What is the difference between a phylogenetic tree and a cladogram?

Phylogenetic trees only show hypothesized relationships.

Cladograms show evolutionary history among species.

What is an autotroph and a heterotroph? Give examples of each:

Autotrophs make their own food.

Heterotrophs do not make their own food.

Which of these characteristics can be used to determine the Kingdom an organism belongs in?

1. type of energy they require

2. type of body structure

3. type of root system

4. cell type

5. type of reproduction

All of these except the type of root system

What is the central nervous system made up of?

What does the peripheral nervous system do?

Provides a pathway to and from the central nervous system.

How does information travel from the central nervous system to a muscle or gland?

Motor Neurons

What does the cerebellum do?

It coordinates muscle movement, subconscious activities and some balance functions.

It contributes to coordination, precision and accurate timing.

What does this structure do?

The hypothalamus regulates hunger and thirst.

What is this structure and what is its function?

This is the cerebrum.

It receives signals and controls movement.

What are sensory neurons and what do they do?

Sensory neurons are typically classified as the neurons responsible for converting external stimuli from the environment into internal stimuli. They are activated by sensory input (vision, touch, hearing, etc.), and send projections into the central nervous system that convey sensory information to the brain or spinal cord.

What is the autonomic nervous system and what does it control?

As part of the peripheral nervous system, the autonomic nervous system controls involuntary functions of the internal organs such as the heart rate, digestion, respiratory rate and perspiration.

Where is the myelin sheath found and what does it do?

The myelin sheath insulates the axons and is essential for the proper functioning of the nervous system.

The main purpose of the myelin sheath is to increase the speed at which impulses move along the myelinated fiber.

Multiple sclerosis is a disease that destroys the myelin sheath, thus affecting the nervous system.

How do narcotics affect the nervous system?

When the body feels pain, it releases natural painkillers called enkephalins, but they only last a few seconds because the enzymes in our bodies neutralize them.

Narcotics mimic the effects of enkephalins thus relieving pain and can be used for more extensive periods of time.

What are neurotransmitters?

Communication of information between neurons is accomplished by movement of chemicals across a small gap called the synapse. Chemicals, called neurotransmitters, are released from one neuron at the presynaptic nerve terminal. Neurotransmitters then cross the synapse where they may be accepted by the next neuron at a specialized site called a receptor.

Psychoactive drugs like nicotine do what?

Affect the CNS by changing the activity of the synapses by mimicking the action of a neurotransmitter.

What effect does drinking alcohol have on the body?

It decreases the activity of the central nervous system.

What do hormones do? Hormones are your body's

chemical messengers. They travel in your bloodstream to tissues or organs. They work slowly, over time, and affect many different processes, including:

Growth and development Metabolism - how your body

gets energy from the foods you eat

Sexual function Reproduction Mood

Hormones are removed from the blood and broken down in the liver.

What is hypothyroidism?

Hypothyroidism is a condition in which the thyroid gland does not make enough thyroid hormone which controls metabolism.

In adults, it can cause a lack of energy and unintentional weight gain.

What does the pancreas do?

The pancreas is a gland organ in the digestive system and endocrine system. It is both an endocrine gland and digestive organ.

It produces hormones like insulin, glucagon, somatostatin and pancreatic polypeptide.

It also secretes pancreatic juice and enzymes that help with the absorption of nutrients in the small intestine.

Why do cells divide? When cells get to be a

certain size they will divide because:

New cells are needed for growth.

If the cell gets too big, it cannot transport nutrients properly.

The DNA cannot be copied quickly enough for cells that are too large.

Cells that do not respond to checkpoints can become cancer cells.

What is the difference between bacteria and viruses?

Bacteria reproduce asexually. (binary fission)

Viruses reproduce through a host cell.

Bacteria can be killed with antibiotics.

Viruses cannot be killed with antibiotics.

Both are considered to be pathogens because they cause disease.

Killed or weakened pathogens are used to make vaccines.

What is haploid, diploid and homologous?

Haploid cells have only one set of unpaired chromosomes. These are the sex cells and pass on hereditary traits.

Diploid cells have two haploid sets of chromosomes

Homologous chromosomes contain pairs of chromosomes that contain genes that code for the same traits.

One of the cell organelles has its own DNA, which one is it?

The Mighty Mitochondria!

Hint: It is the Powerhouse of the Cell!

What is recombinant DNA?

A strand of DNA formed by combining DNA from two different species.

RNA is used to join the DNA molecules.

What is it called when genes from one organism is added to another organism?

Genetic engineering.

By adding Bacillus thuringiensis to certain plants, they are able to resist insects.

Who is Dolly?

Dolly was the first cloned sheep and important because sheep had never responded to gene technology procedures before.

Cloning is a process by which science can eliminate undesirable traits in new individuals.

Professor Ian Wilmut and Dolly 1997