Snow Days - Everyone Stay Warm!

Snow Days - Everyone Stay Warm

See if you can get a 100% on the questions scattered through this assignment.

Take as many attempts as you need.

When you get a question right or wrong, ask yourself: why is this the right answer? Or why was it the wrong answer?

Multiple Choice

Let's start by seeing what you remember.

Genetic evidence suggests which of the following is true?

• The world is a few thousand years old.

• All species on Earth share much of the same DNA and share a common ancestry.

• Different species have no DNA in common.

• Human beings evolved from chimpanzees.

Multiple Choice

What is a species?

• The process whereby organisms better adapted to their environment tend to survive and reproduce.

• The ability of an organism to survive, reproduce, and pass on its genes to its offspring.

• A distinct group of organisms that can reproduce only with each other.

• Any change in an organism's DNA.

Multiple Choice

The ability of an organism to survive, reproduce, and pass on its genes to its offspring is:

• Physical Fitness

• Evolution

• Natural Selection

• Biological Fitness

Multiple Choice

The period from 250 to 65 million years ago was known as the Age of the Dinosaurs.

What happened to the dinosaurs?

• They all went extinct and none survive today.

• They evolved to live in the ocean.

• They evolved to live in the trees.

• Most of them went extinct, but some survived and evolved to become birds.

Multiple Choice

Dinosaurs were doing very well on Earth until a huge, completely random disaster struck and killed almost all of them.

Which mechanism of evolution does that represent?

• Natural Selection

• Genetic Drift - Bottleneck Effect

• Gene Flow

• Artificial Selection

Take a Closer Look

If you had to compare the dinosaurs in this image to any creatures living today, what would you compare them to?

Look at the feet.

Look at the feathers.

If you said 'birds', give yourself a pat on the back.

Scientists believe modern birds are descended from dinosaurs.

What happened to the dinosaurs?

Scientists believe a meteor struck the Earth about 65 million years ago and killed most of the dinosaurs.

The meteor's impact drastically altered Earth's climate for many years. Only smaller animals, including many mammals and some small dinosaurs, survived this new climate.

Fossil Records

Scientists who study dinosaur fossils often find large numbers of these fossils all in the same area.

Whenever many fossils are found together in one area, a sudden change in the environment is the most likely cause.

Comparing Ancient and Modern DNA

DNA tends to decompose even when fossilized. The oldest intact DNA scientists have found is about 1 million years old.

However, dinosaurs lived at least 65 million years ago. This is why scientists have not been able to find intact dinosaur DNA.

Comparing Ancient and Modern DNA

However, scientists do know that ALL SPECIES that have EVER LIVED share some of the same DNA.

Scientists also know that all DNA shares a common basic structure.

Comparing Ancient and Modern DNA

This means that at least some human DNA is the same as dinosaur DNA.

It also means we know what the basic structure of dinosaur DNA would be, because it would have the same basic structure as our DNA.

Structure of DNA

DNA makes up the genetic code; the code of life.

Every living thing has its own unique sequence of DNA.

However, all DNA is made up only a few basic parts.

Structure of DNA

Look at the model of DNA to the right.

It shows that DNA is made up of a sugar phosphate backbone and base pairs.

All DNA has this basic structure.

Write this DOWN!!!

DNA always consists of:

1. A Phosphate

2. Deoxyribose Sugar

3. Nitrogenous Bases

Write this DOWN!!!

There are four types of nitrogenous bases:

1. Adenine

2. Thymine

3. Guanine

4. Cytosine

Study this image carefully

What do you think each letter in this image stands for?

Go back to previous slides if you need to refresh your memory.

Which letters seem to go together?

Multiple Choice

What do you think the letter 'D' stands for in this image?

• DNA

• Don't know, don't care

• Deoxyribose Sugar

• Dinosaur

Multiple Choice

What do the letters A, T, G, and C stand for?

• The four types of life: animal, terrestrial, garden, and celestial.

• The four nitrogenous bases: adenine, thymine, guanine, and cytosine.

Multiple Choice

Which two letters always seem to be paired together?

• D is always paired with C.

• G is always paired with T.

• P is always paired with A.

• C is always paired with G.

The four nitrogenous bases always pair up!

Adenine always pairs with Thymine.

A with T, and T with A.

Guanine always pairs with Cytosine.

G with C, and C with G.

Write that down!!!

Can DNA be used to bring back extinct species?

Scientists cannot find intact dinosaur DNA because it would be at least 65 million years old, and DNA rarely lasts more than a million years.

However, the wooly mammoth only went extinct several thousand years ago. Could scientists bring the wooly mammoth back?

Open Ended

What are the main obstacles preventing scientists from bringing dinosaurs back from extinction?

Could scientists bring other species back from extinction?

Multiple Select

If you compared dinosaur DNA to human DNA, what would you find?

Select all that apply.

• They would have nothing in common because humans and dinosaurs are so different.

• They would have completely different structures because DNA structure changes from one species to another.

• They would be different, but they would also have some DNA in common because ALL species share a common ancestry.

• They would have the same basic structure because ALL DNA has the same basic structure, regardless of species.

Multiple Choice

Which choice accurately describes the structure of DNA?

• A phosphate, deoxyribose sugar, and nitrogenous bases.

• A phosphate, ribose sugar, and nitrogenous bases.

• A phosphorous, cellulose, and amino acids.

• Photosynthesis and cell respiration.

Multiple Choice

The four nitrogenous bases found in DNA are:

• Phosphate and deoxyribose sugar

• Nitrogen, Oxygen, Hydrogen, and Flourine

• Adenine, Thymine, Guanine, and Cytosine

• Adenine, Thymine, Guanine, and Uracil

Multiple Choice

You are a paleontologist (someone who studies dinosaur fossils).

You find a large number of fossils together in one area.

What does this tell you?

• These dinosaurs must have lived in herds.

• Humans must have set a trap for the dinosaurs in this area.

• The meteor that killed the dinosaurs must have struck here.

• There was likely a sudden environmental shift that caused so many of them to die in one area.

Multiple Select

Which nitrogenous bases always pair together?

Select all that apply.

• Adenine with Cytosine.

• Cytosine with Guanine.

• Thymine with Adenine.

• Adenine with Thymine.

• Guanine with Adenine.

Multiple Select

If you compared plant DNA, insect DNA, and human DNA, what would you find?

Select all that apply.

• They would have the same basic structure because ALL DNA has the same basic structure, regardless of species.

• They would have completely different structures because DNA structure changes from one species to another.

• They would be different, but they would also have some DNA in common because ALL species share a common ancestry.

• They would have nothing in common because plants, insects, and humans are so different.