Genetics Heredity Genes DNA Chapter Introduction

using only four letters? ! ! How to create all living things and make them exist for billions of years on earth… using only four letters? ! ! Chapter Introduction

DNA and Genetics What is DNA? How does DNA control a cell? How do changes in DNA affect traits? Lesson 3 Reading Guide

Lesson 3 Reading Guide - Vocab DNA and Genetics DNA nucleotide replication RNA transcription translation mutation Lesson 3 Reading Guide - Vocab

The Structure of DNA DNA (deoxyribonucleic acid) is a very long molecule that stores genetic information. A gene is a segment of DNA that controls a trait. DNA is shaped like a twisted ladder called a double helix. It is packaged with histones to make chromosomes. DNA Gene Double helix Lesson 3

DNA Gene Lesson 3

DNA Gene Lesson 3

The Structure of DNA (cont.) What is DNA? Lesson 3

The Structure of DNA (cont.) Each rung of the DNA ladder is made up of nucleotide pairs. DNA uses four kinds of nucleotides: Adenine Thymine Cytosine Guanine This long “zipper” structure is important to DNA’s function. Nucleotide Adenine Cytosine Guanine Thymine Lesson 3

The Structure of DNA (cont.) Each rung of the DNA ladder is made up of nucleotide pairs: A-T and C-G. A-T C-G Lesson 3

Replication is the process of copying one DNA strand to make two DNA strands. Lesson 3

Making Proteins The central dogma of genetics says: DNA makes RNA (also more DNA) RNA makes proteins DNA controls a cell by making proteins, these proteins make other molecules or control reactions. DNA RNA RNA proteins Lesson 3

Making Proteins The central dogma of genetics say: Lesson 3

Making Proteins (cont.) DNA RNA Name Deoxyribonucleic acid Ribonucleic acid Structure Double helix Single helix Purpose Store instructions Translate instruction to proteins Components nucleotides Bases ACGT ACGU (U is Uracil) Lesson 3

Transcription is the process of making RNA from DNA—is the first step in making a protein. Lesson 3

Making Proteins (cont.) What is the role of RNA in protein production? Lesson 3

Translation is the process of making a protein from RNA. Lesson 3

Mutations A change in the nucleotide sequence of DNA is called a mutation. Mutations can be caused by replication errors, infection and exposure to strong radiation or chemicals. Mutation Replication errors Infection Radiation Chemicals Lesson 3

Mutations include insertion, deletion and substitution. Lesson 3

Mutations (cont.) Some mutations cause cancer, genetic disorders, or create new pathogens. Some mutations produce beneficial traits that help with adaptation. Some mutations do not produce observable effects. Lesson 3

Mutations (cont.) How do changes in the sequence of DNA affect traits? Lesson 3

DNA is a complex molecule that contains the code for an organism’s genetic material. Lesson 3

RNA carries the codes for making proteins. Lesson 3

An organism’s nucleotide sequence can change through the deletion, insertion, or substitution of nitrogen bases. Lesson 3

What is created through transcription? A. DNA B. mutations C. mRNA D. protein Lesson 3

In DNA, which of the following is paired with guanine? A. adenine B. cytosine C. thymine D. uracil Lesson 3

Which of the following describes the mutation that occurs when three base pairs are added? A. insertion B. substitution C. transgression D. deletion Lesson 3

5. Any condition present at birth is genetic. Do you agree or disagree? 5. Any condition present at birth is genetic. 6. A change in the sequence of an organism’s DNA always changes the organism’s traits. Lesson 3

Interactive Concept Map Chapter Review Standardized Test Practice Key Concept Summary Interactive Concept Map Chapter Review Standardized Test Practice Chapter Review Menu

Inherited genes are the basis of an organism’s traits. The BIG Idea

Lesson 1: Mendel and His Peas Mendel performed cross-pollination experiments to track which traits were produced by specific parental crosses. Mendel found that two factors—one from a sperm cell and one from an egg cell—control each trait. Dominant traits block the expression of recessive traits. Recessive traits are expressed only when two recessive factors are present. Key Concepts 1

Lesson 2: Understanding Inheritance Phenotype describes how a trait appears. Genotype describes alleles that control a trait. Punnett squares and pedigrees are tools to model patterns of inheritance. Many patterns of inheritance, such as codominance and polygenic inheritance, are more complex than Mendel described. Key Concepts 2

Lesson 3: DNA and Genetics DNA contains an organism’s genetic information. RNA carries the codes for making proteins from the nucleus to the cytoplasm. RNA also forms part of ribosomes. A change in the sequence of DNA, called a mutation, can change the traits of an organism. Key Concepts 3

According to Mendel, how many factors controlled each trait? B. 2 C. 3 D. 4 Chapter Review

Which of the following describes alleles that control a trait? A. phenotype B. codominance C. genotype D. polygenic inheritance Chapter Review

Which of the following describes an error made during the copying of DNA? A. transcription B. replication C. translation D. mutation Chapter Review

If parents have the genotypes RR and Rr, what percentage of offspring will have a Rr genotype? B. 50% C. 75% D. 100% Chapter Review

Which of the following describes the process of making a protein from RNA? A. translation B. transcription C. replication D. mutation Chapter Review

In fruit flies, the allele for red eyes (R) is dominant over the allele for white eyes (r). If parents have the genotypes Rr and Rr, what percentage of offspring will have red eyes? A. 25 percent C. 75 percent B. 50 percent D. 100 percent Chapter Review

Heredity is associated with which of the following? A. chromosomes B. genes C. genotype D. all of the above Chapter Review

Which occurs when multiple genes determine the phenotype of a trait? A. polygenic inheritance B. mutation C. environmental influence D. codominance Chapter Review

In DNA, which of the following is true? A. adenine bonds with guanine B. cytosine bonds with adenine C. thymine bonds with adenine D. none of the above Chapter Review

What is the product of replication? A. DNA B. RNA C. mRNA D. proteins Chapter Review

Cut out the four items below, fill in the “key” with words, fill in the letters in the empty shapes. Assemble the DNA like an zipper that is being opened.