Name: Date: Period: Genetics and Heredity S8.B2.2 What is DNA? Cells use a chemical code called

Size: px

Start display at page:

Download "Name: Date: Period: Genetics and Heredity S8.B2.2 What is DNA? Cells use a chemical code called"

Felicity Ramsey
5 years ago
Views:

to form DNA is passed from DNA s Discovery In 1953, James and Francis discovered the The work of Rosalind lead to Franklin said

1 Name: Date: Period: Genetics and Heredity S8.B2.2 What is DNA? Cells use a chemical code called or DNA carries all of the DNA is located in the During cell division it wraps around proteins to form DNA is passed from DNA s Discovery In 1953, James and Francis discovered the The work of Rosalind lead to Franklin said DNA is The Structure of DNA DNA is called a because it looks like a The are made of alternating ( ) and molecules The are made up of a pair of There are 4 types of nitrogen bases ( ) ( ) ( ) ( ) 1

2 DNA Pairing The nitrogen bases have a (A) pairs with (T) (G) pairs with (C) This pairing pattern occurs because the amount of equals the amount of ; the amount of equals the amount of The pairs are held together by You Try. Write the matching nitrogen bases next to the strand of DNA C C G A T T A Genes Every living thing carries a A is a structure found of the cell. Each contains. A is a part of that contains the You have different for each of the different that you inherit. Genes Each contains except for sex cells ( ) which contain. Therefore, you receive of your chromosomes from your mother ( ) and from your father ( ) for a total of. Remember genes are located on your chromosomes. 2

3 Genetics In the 1800s, Gregor Mendel was interested in learning how characteristics are. To study this he bred pea plants because they were. Genetics The field of biology that investigates is called. Mendel s work with pea plants formed the basis of genetics. His results lead to heredity. is the transmission of. Pea Plant Characteristics Mendel studied the seven characteristics of pea plants. Each characteristic occurred as one of two traits. Pea Plant Characteristics Plant Height Pod Color Pod Appearance Seed texture Seed color Flower position on stem Flower color Inflated or Constricted Axial (along stem) or Terminal (on top of stem) Mendel s Work Mendel collected seeds from pea plants and studied them. He then how the plants. He eliminated any possibility that birds, insects, or wind would carry the pollen. He then bred plants that were. 3

4 only produced the, for example, tall plants only produced tall plants Mendel s Crosses Mendel then crossed or bred pure pea plants by transferring pollen from one type of plant to another. Mendel s Crosses Tall stem x short stem Inflated pod x constricted pod Yellow seed x green seed Axial flower x terminal flower Mendel s Observations All of the plants in the crosses listed are known as. Mendel labeled parental plants. The of the P 1 Generation are known as the Generation. Mendel noticed that all of the plants in the displayed from the P 1 generation. A is a, or of an organism. 4

Mendel s Observations Mendel s Explanation Mendel concluded that or the other trait. For example, Mendel called purple flowers a, the characteristic that prevails.

5 Mendel s Observations Mendel s Explanation Mendel concluded that or the other trait. For example, Mendel called purple flowers a, the characteristic that prevails. Mendel called the trait that in F 1 the, or the trait overridden by the dominant trait Think of recessive traits as being In the flower example the white flower would be recessive. Dominant vs Recessive If one parent has for a and the other parent has material for a, the offspring will be. An offspring can if. traits are shown with a traits are shown with a Dominant or Recessive Which trait will the offspring have? Dominant or Recessive? T = t = TT = Tt = tt = 5

6 Punnett Square A Punnett Square is a diagram used to find the possible traits of offspring. Example: Presence of freckles F = freckles f = no freckles How many children will have freckles? How many will not have freckles? Practice T = tall t = short How many offspring will be tall? How many offspring will be short? 6

Practice A purple flower (PP) is crossed with a white flower (pp), what will be offspring be? Pedigree Chart A pedigree chart is a It is like a family tree that shows.

7 Practice A purple flower (PP) is crossed with a white flower (pp), what will be offspring be? Pedigree Chart A pedigree chart is a It is like a family tree that shows. Pedigree Chart Each row in the chart shows a different generation of family members. Squares = Circles = A circle and square A vertical line and bracket connects. Shaded circle or square Pedigree How many males have trait? 7

8 How many females have trait? How many men are there? How many women are there? 8

Name Date Class. This section describes how Gregor Mendel identified the method by which characteristics are passed from parents to their offspring.

Name Date Class. This section describes how Gregor Mendel identified the method by which characteristics are passed from parents to their offspring. Mendel s Work This section describes how Gregor Mendel identified the method by which characteristics are passed from parents to their offspring. Introduction 1. Gregor Mendel experimented with hundreds