1. Genetics
Heredity
Genes
DNA
Chapter Introduction

2. 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

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

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

5. 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

6. DNA
Gene
Lesson 3

7. DNA
Gene
Lesson 3

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

9. 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

10. 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

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

12. 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

13. Making Proteins
The central dogma of genetics say:
Lesson 3

14. 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

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

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

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

18. 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

19. Mutations include insertion, deletion and substitution.
Lesson 3

20. 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

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

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

23. RNA carries the codes for making proteins.
Lesson 3

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

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

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

27. 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

28. 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

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

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

31. 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

32. 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

33. 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

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

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

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

37. 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

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

39. 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

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

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

42. 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

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

45. 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.