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...