Genes and DNA

Unit 8, Quiz 2

DNA and Genes

😎 Instructions

• This is a blended lesson and quiz.

• In other words: We will review concepts and count the questions as a grade for the quiz grade due today (Friday).

• Read every slide carefully.

• Repeat as many times as you like for the perfect score!

Ready?

First, let's do some warm up questions.

Multiple Choice

Which of the following statements best describes DNA?

• Has the shape of a single helix, short molecule.

• Only has instructions for making bone cells.

• In humans, it contains 46 chromosomes total.

Multiple Choice

Which of the following statements best describes DNA?

• It has genes inherited from both parents.

• Has only about 2,000 base pairs in its code.

• Only carries one version of every gene.

So, what do you know about the structure of DNA?

+ Double helix

+ Has 4 nucleotides

+ They make 2 base pairs

+ It's a code!

+ Base pairs are A+T and G+C

Multiple Choice

How many base pairs of nucleotides are in DNA?

• 4 base pairs

• 2 base pairs

• 0 base pairs

Multiple Choice

In DNA, the base pairs A and T are always put together. Which base pair is supposed to always go to gether with C?

• T

• N

• G

So, about genes...

+ Humans have about 25,000 genes

+ They're written like sentences:

--- Each base pair is a letter

--- Three letters make a codon

--- Codons are like words

--- Many codons make a gene

But wait, there's more!

More about genes...

+ One copy from each parent

+ Each copy is called an allele

+ Only one copy is read at a time

--- This is the "dominant" copy

--- The other one is "recessive"

--- Unless there's TWO recessives

+ Dominant alleles always show

--- Examples: dark hair/eyes

Multiple Choice

Marie got a copy of the same gene for hair color from each parent. Her mom gave a dominant brown hair allele and her dad gave a recessive red hair allele. What color is Marie's hair most likely going to be?

• Red hair

• Brown hair

• Blonde hair

• Black hair

Here's a bonus question... Ready?

Yes, you can get extra credit if you answer it correctly!

But it's challenging...

Fill in the Blanks

If one strand of DNA reads "TAACGTTACCGA" then the other half says "

" (remember, it's the matching base pairs)!