Chapter 1 Heredity Prepared by: GOAD s Team
IMPORTANT VOCABULARY WORDS Traits Character Genes Allele Genotype homozygote heterozygote Dominant recessive phenotype
WHAT IS HEREDITY?
HEREDITY - is a passing of traits from parents to offspring. Parents offspring
CHARACTER TRAITS Height Tall? Short?
CHARACTER TRAITS Eye color Brown? Black? Blue?
CHARACTER TRAITS Skin color Brown? White? Dark?
CHARACTER TRAITS Hair Curly? Straight?
SMART CHECK: Which of the following examples is a character that can pass from parents to offspring? A. Guitar skill B. Blue eyes C. AB blood type
SMART CHECK: Which of the following examples is a character that can pass from parents to offspring? A. Guitar skill B. Blue eyes C. AB blood type Traits
Understanding Genes, DNA and Chromosomes
MIND-MAPPING Nucleus Chromosomes DNA De-oxy-ribo-nucleic acid Genes
Nucleus Chromosomes DNA Genes
Inside a nucleus are The Chromosomes
What is a Chromosome? A thread-like structure that contains DNA.
What is the job of chromosome? - Wrap the DNA - Guard the DNA
How many chromosomes do humans have? 46 Chromosomes Sperm = 23 chromosomes + Egg cell = 23 chromosomes 22 chromosomes are called autosomes 1 chromosome is called sex chromosomes Male = X and Y chromosome Female = XX chromosome
Look at the picture!
SMART CHECK: If a person has X and Y chromosomes, what will be the gender? A. Male or boy B. Female or girl
SMART CHECK: If a person has X and Y chromosomes, what will be the gender? A. Male or boy B. Female or girl
CHECK YOUR UNDERSTANDING: If no chromosomes, DNA would be very long and cannot fit inside the cell, That s why the job of the chromosome is to wrap the DNA.
Now let s talk about DNA
Nucleus Chromosomes DNA Genes
Inside a chromosome is. The DNA (de-oxy-ribo-nucleic acid)
What is a DNA? - a long protein molecule that makes up genes.
What is the function (job) of DNA? - It has life information and instructions. - It tells every cell what to do.
4 nucleotides of the DNA Adenine (A) Thymine (T) Cytosine (C) Guanine (G) They are pairs They are pairs
What are the jobs of 4 nucleotides? Adenine (A) Thymine (T) Cytosine (C) Guanine (G) They are the bank of DNA Save all codes and information
Now let s talk about Genes
Nucleus Chromosomes DNA Genes
Inside the DNA are. The Genes
WHAT IS A GENE?
GENE - is a unit of heredity - is made up of DNA
What is the function (job) of Genes? - It carries information to every cell. - It determines your physical appearance (what you look like).
Chromosomes DNA Genes They tell the cell what to do to make human
COMPARISON TO A BOOK The DNA nucleotides The ink and pen The letters genes The sentence chromosomes The chapter
SMART CHECK: What is the main job of our genes? A. Carries DNA B. Carries information C. Carries blood
SMART CHECK: What is the main job of our genes? A. Carries DNA B. Carries information C. Carries blood
Genes and Alleles DNA genes alleles - Alleles come from genes
Genes and Alleles Genes Alleles Alleles Alleles Genes DNA Genes Alleles Alleles Alleles Genes
2 Types of Allele: 1. Dominant 2. Recessive
2 Types of Allele: 1. Dominant - Stronger allele. It can be observed easily. Brown eye has a stronger allele.
2 Types of Allele: 2. Recessive - weaker allele and cannot be observed easily
Formula Dominant + Dominant = DD (Dominant dominant) Dominant + recessive = Dr (Dominant recessive) recessive + recessive = rr (recessive recessive)
SMART CHECK: How can you observe recessive trait? A. With dominant allele B. With recessive allele
SMART CHECK: How can you observe recessive trait? A. With dominant allele B. With recessive allele
Understanding Genotype and Phenotype
Genotype Phenotype meaning Information in genes and alleles A trait that you can see and observe example Code and information to make blue eyes hair color, eye color, height and weight Job Prepare and tell the code to phenotype Do the code to be seen
2 Types of Genotype: 1. homozygous 2. heterozygous
- Same alleles Homozygous
Heterozygous - Different alleles Blue has small a and Sky blue has big A
SMART CHECK: The form of the gene that is weaker and you cannot see? A. Dominant B. Recessive C. Phenotype
SMART CHECK: The form of the gene that is weaker and you cannot see? A. Dominant Can be seen B. Recessive C. Phenotype Can be seen
SMART CHECK: rr would result in a genotype. A. Homozygous B. heterozygous
SMART CHECK: rr would result in a genotype. A. Homozygous B. heterozygous
SMART CHECK: If the gene can be seen, it is called A. genotype B. phenotype
SMART CHECK: If the gene can be seen, it is called A. genotype B. phenotype
SMART CHECK: In the picture. Who has a dominant trait? A. Father B. Mother
SMART CHECK: In the picture. Who has a dominant trait? A. Father B. Mother
How does heredity (passing of traits) work? Can you explain how it works?
MAP SUMMARY heredity parents Passing of traits offspring cell Chromosomes DNA recessive alleles dominant genotype phenotype genes homozygous heterozygous