Presentation on theme: "Genetics: The Science of Heredity"— Presentation transcript:
1 Genetics: The Science of Heredity Coach JulienTeam 7-2
2 StandardS7L3 Students will recognize how biological traits are passed on to successive generations.a.. Explain the role of genes and chromosomes in the process of inheriting a specific trait.c. Recognize that selective breeding can produce plants or animals with desired traits
3 VocabularyHeredity- the passing of physical characteristics from parents to offspringTrait- a characteristic that an organism can pass on to its offspring through its genesGenetics-t he study of heredityFertilization-the joining of sperm and eggPurebred- organism is the offspring of many generations that have the same trait
4 Gene- factor that controls a trait Alleles- different forms of a geneDominant allele- trait always shows up in the organism when the allele is presentRecessive allele- is hidden whenever the dominant allele is presentHybrid- organism that has two different alleles for a traitProbability- a number that describes how likely it is that an event will occur.
5 Punnett Square- chart that shows all the possible combinations of alleles that can result from a genetic cross.Phenotype- is the physical appearance of an organismsGenotype- an organism’s genetic makeup or allele combinationHomozygous- an organism that has two identical alleles for the same traitHeterozygous- an organism with two different alleles for the same trait
6 Codominancce-the alleles are neither dominant nor recessive: both alleles are expressed in the offspring.Meiosis-the process by which the number of chromosomes is reduced by half to form sex cells (sperm & eggs).Messenger RNA-copies the coded message from the DNA in the nucleus, and carries the message to the ribosome in the cytoplasm
7 Transfer RNA-carries amino acids to the ribosome and adds them to the growing protein Mutation-any change in a gene or chromosome
8 Chromosomes are made up of Many genes joined together
9 A heterozygous organism has Two different alleles for a trait
10 Which nitrogen base in RNA is NOT part of DNA Uracil
12 Where does protein synthesis take place? On the ribosomes in the cytoplasm of the cell
13 The different forms of a gene are called alleles
14 Which term refers to physical characteristics that are studied in genetics? phenotype
15 A mutation is harmful to an organism if it Reduces the organism’s chances for survival and reproduction
16 What is a mutation?Any change in a gene or chromosome
17 What do transfer RNA molecules do during protein synthesis? Carry amino acids and add them to the growing protein
18 What does messenger RNA do during protein synthesis? Copies the coded message from the DNA and carries it into the cytoplasm
19 The order of the bases along a gene determines the order in which Amino acids are put together to form a protein
20 What determines the genetic code? The order of nitrogen bases along a gene
21 When sex cells combine to produce offspring, each sex will contribute Half the number of chromosomes in body cells.
22 What happens during meiosis? Chromosomes pairs separate and are distributed into new sex cells.
23 Walter Sutton discovered that the sex cells of grasshoppers have Half the number of chromosomes found in the body cells.
24 What is the chromosome theory of inheritance? Genes are carried from parents to offspring on chromosomes.
25 Purebred chicken with white feathers is crossed with a purebred chicken that has black feathers. Each of their offspring has both black and white feathers. Why does this happen?The alleles for feather color are neither dominant nor recessive.
26 An organism’s physical appearance is its phenotype
27 If a homozygous black guinea pig (BB) is crossed with a homozygous white guinea pig (bb) ,what is the probability that an offspring will have black fur?75%
28 What does a Punnett square show? All the possible outcomes of a genetic cross
29 What is the probability of producing a tall pea plant from genetic cross between two hybrid tall pea plants?Three in four
30 What is probability?A number that describes how likely it is that an event will occur
31 What does the notation Tt mean to geneticists? One dominant allele and one recessive allele
32 What does the notation TT mean to geneticists? Two dominant alleles
33 Scientists call an organism that has two different alleles for a trait a hybrid