7th science sub plan 1

7th science sub plan 1

by Mrs. McKinney

​Today we are learning Classic Genetics

​ Summarize why some traits cannot be inherited and how inherited traits are passed from one

generation to the next by genes.

• Explain why sexual reproduction produces more genetic variation than asexual reproduction.

• Identify basic patterns of inheritance.

• Use Punnett squares and pedigree diagrams to predict the probabilities of certain genotypes and phenotypes.

• Describe the relationships among genes, chromosomes, and DNA and their functions in cells and living things.

• Describe the structure of DNA and its role in the building and functioning of organisms.

• Construct an explanation for how changes in DNA can affect organisms.

• ​

• ​These are from lessons 5.1 and 5.2 , but don't worry if you are not there yet

​First, listen to this song

​

​on youtube, search for

​

​Science Rap Academy DNA

Multiple Choice

DNA stands for deoxyribonucleic acid. What cell organelle would hold this main nucleic acid?

• the nucleus

• the cytoplasm

• the cell membrane

• the DNA is never inside the cells

​reproduction

​there are 2 types of reproduction

​

​sexual reproduction

​ takes 2 parents

​ the offspring (kids)

​ are each different

​

​asexual reproduction

​ only takes a mom

​ the offspring is

an exact copy of mom

​Mutations

​DNA is made up of A, T, C, and G

​

​sometimes, typos are made

​ these are called mutations

​

​one type is called a

substitution mutation

​substitute means replace one with another

​

​in the pic, notice the C changed to a T. nothing else changed

​Insertion mutation

​

​Look at the top DNA chain

​

​DNA is read three letters

​ at a time

​

​When a mutation type occurs

​ and inserts an extra nucleotide letter

​

​all of the 3-letter words after that mutation are messed up (no more cats )

​Deletion mutation

​This time, a letter is deleted

​ and all the words are shifted

​

​this shifting is called a

​ Frameshift mutation

​it is a type of mutation that

​occurs when everything

afterwards is messed up

​

​insertion and deletion are both types of frameshift mutations

​mutations

​

mutations can be caused by

​ random typos (copying mistakes)

​ environment (mutagens)

​ also called carcinogens

​

​they can be

​ helpful

​ harmful

​ deadly (fatal)

Multiple Choice

The only cells that are used to make babies in sexual reproduction are the egg and sperm.  Therefore, for a mutation to pass on to the baby, the mutation must be in the

• egg or sperm

• skin or bone cells

• brain

• big toe of the right foot

​another song!

​now, search on youtube for

​

​

​

​science rap academy phenotype

​

​listen and take notes

Multiple Choice

The environment can affect your genetic output, or phenotype.

Ahmed had genes to get very tall, but he becomes very sick during the years he is supposed to

grow. This is an example of an ______________ factor.

• environmental

• genotypical

• nucleic acid

• He would still be very tall

Multiple Choice

Too much sunlight causes changes in DNA called ________.

• genotype

• environment

• mutations

• RNA

​Mendel and his peas

​Gregor Mendel was a monk that grew peas and figured out some classic genetic stuff.

​

He controlled who was the mom and the dad of these plants to do experiments.​

​

​for example,

​The height of the plants and the color of the peas did not affect each other.

​

​Dominant and recessive

​

​If you have 2 different forms of a gene,

​ they have to decide which one will show

​

​in most cases, there is a

​ Dominant gene that we represent with a capital letter

​ and a

​ recessive gene that we represent with an lower case letter

​

Multiple Choice

In the gene combination Gg, which letter stands for a recessive gene?

• G

• g

• Gg

• There is no way to tell without experiments

​Homozygous and heterozygous

​homo-

​ means the same

​

​hetero-

​ means different

​

​if both are dominant

​or both are recessive,

​ it is homozygous

Multiple Choice

If you have one dominant gene and one recessive gene, that organism is...

• heterozygous

• homozygous

• goofy

• fighting to see which gene will win

​Punnett squares

​To start a Punnett square,

​ draw a 4-paned window

​ put the genotype of the dad at the top

​ and the genotype of mom on the side

​ one letter per pane

​

​Each of the 4 panes represents a 25% chance the offspring will have the resulting genes

​to solve

​each of the top letters goes down

​

​each of the left letters goes across

​

​you should end up with two letters in each box

​

​on youtube, watch

​Mahalo Punnett

Multiple Choice

The four panes would have

• Bb , bb , Bb , bb

• BB, Bb , Bb , bb

• Bb , Bb , Bb , Bb

• BB , bb , bb , bb

Multiple Choice

These offspring would be

• tt, tt, tt, tt

• TT , TT , tt , tt

• TT , Tt , Tt , tt

• They are all T's , what is the difference?

​other genetic inheritances

​Punnett squares work with dominant

and recessive genes of traits controlled

with one gene

​

​incomplete dominance is where

red and white really would make pink, or show the average trait

​

codominant is where both traits would show, such as a flower having red and white stripes

​

​then, there are other traits that are controlled by more than one gene!

​pedigree

​

a family tree that shows a genetic trait

​

​females are circles

​males are squares

​

​light colored shapes do not have that trait

​dark colored shapes do have the trait

Multiple Choice

On the bottom row, 8 is a 

• male with the trait

• female with the trait

• female that does not have the trait

• there is no way to tell

Multiple Choice

Punnett squares work to predict every genetic trait

• oh, yes!

• no, because there are actually many different ways genetics can work

• no, because all punnett squares are wrong

• That Mendel dude, well... he just didn't get out much and was confused.