Chapter 4 Flashcards
What is the name of the factors that control traits that Mendel discovered
Gene
In Mendels experiments, what proportion of the plants in the F2 generation had the trait that had been missing in generation F1
3/4 were tall 1/4 were short
What do the following notations mean to genetics: TT, Tt, tt
TT – Dominant Tt – dominant tt- recessive
What was the dominant trait in Mendels experiments (tall or short)?
Tall
What are the possible genotypes for a tall pea plant
TT, Tt
What does a punnet square show
It shows all possible combinations of alleles in a genetic cross
What is a genotype? What do you write down when I ask for a genotype?
The genotype is its genetic makeup. You write down the alleles. Ex. TT, Tt
What is a phenotype? What do you write down when I ask for a phenotype?
The phenotype is its physical appearance. You write down the dominant or recessive trait. Ex. Tall stem or short stem
What is the definition of codominance? Give an example of a trait that follows that pattern of inheritance
The alleles are neither dominant or recessive. Ex. FB FW
What is the definition of incomplete dominance? Give an example of a trait that follows the pattern of inheritance.
With incomplete dominance, a cross between organisms with two different phenotypes produces offspring with a third phenotype that is a blending of the parental traits. Ex. Red x white–> pink
What is the chromosome theory of inheritance? Who developed it?
Genes are carried from parents to their offspring on chromosomes. Walter Sutton
What fraction of the chromosomes does each sex Cell contribute when they combine to produce offspring
1/2
What determines the genetic code
The order of the nitrogen bases along a gene
What does the genetic code tell the cell
Specifies what type of protein will be produced
What does messenger RNA do during protein synthesis
Copies the coded message from the DNA in the nucleus, and carries it to the ribosomes in the cytoplasm
What does transfer RNA do during protein synthesis
Carries amino acid and adds them to the growing protein
What are the two major differences between DNA and RNA
DNA has two strands RNA has one strand
What is the definition of a mutation
Any change in a gene or chromosome
What are the three types of mutations? Define them and give an example of each.
One base pair is removed, one base pair is added, one base pair is substituted for another. Look at your packet
What are the different forms of a gene called
Allele
What does homozygous mean
If the alleles are the same or purebred
What does heterozygous mean
If the alleles are different or hybrid
What does purebred mean
The two alleles are the same or homozygous
What does hybrid mean
The two alleles are different or heterozygous
What are chromosomes made of
Genes
Mutations can happen in two types of cells. Name the cells.
Sex cells and body cells
A mutation that happens in which type of cell can be passed to offspring?
Sex cell
How many times does the cell divide during meiosis
2
What are produced by meiosis
4 Sex cells with half the number of chromosomes as the original
What does a set of three bases represent
One specific amino acid
What are the four basic steps of protein synthesis
- Messenger RNA production
- Messenger RNA attaches to a ribosome and carries message to cytoplasm
- Transfer RNA attaches to messenger RNA and reads message
- Protein production continues until a stop code is reached
