STAAR Prep Part 3

STAAR Prep Part 3

Gene Expression, Mutations, Meiosis, Genetics, and Punnett Squares

​Mock STAAR Questions

Questions:
41, 5, 19, 10, 26

Know that genes code for proteins that make up the inherited characteristics of an organism.

​I Will...

Identify the characteristics and components of our DNA as it relates to gene expression.

We Will...

Win for the Day!

​

The process by which a gene gets turned on in a cell to make RNA and proteins. 

Environmental Factors that Affect:

• Temperature

  • Himalayan Rabbits: temperature affects fur pigment

• pH

• nutrition

Gene Expression

Drag and Drop

Each gene along a strand of DNA has the information to tell the cell to produce a specific ​

Placeholder

. A gene is made up of a particular ​

Placeholder

of DNA bases. This sequence acts as a ​

Placeholder

for a protein.

Drag these tiles and drop them in the correct blank above

protein

sequence

code

Multiple Choice

A particular mouse found in northern Canada has a light gray coat in the colder winter months but in the summer months has a dark brown coat. What can you say about this change?

• This is an example of natural selection

• The dominant gene switches generations.

• The gene's expression is controlled by temperature

• The gene's expression is controlled by light exposure

Multiple Choice

Q 41: The temperature at which American alligator eggs are incubated will affect the gender of the offspring. Eggs kept at 30°C tend to hatch mostly female, while eggs kept at 33°C tend to hatch mostly male.

Which statement explains why the temperature affects the gender of alligator hatchlings?

• Gene repair occurs differently at different temperatures

• Gene Expression is different at different temperatures

• Different parts of the embryo's DNA are deleted at different temperatures

• Different parts of the embryo's DNA are duplicated at different temperatures

Know the different types of gene mutations and be able to identify them in a gene sequence.

​I Will...

Identify and illustrate changes in DNA and evaluate the significance of these changes.

​We Will...

WIN OF THE DAY...

​insertion

​Less harmful

​More harmful

​

​

​Point Mutation: one nucleotide is substituted for another

• could create a change or no change at all - (change could code for the same amino acid)

• 3 types: nonsense, missense, and silent

​

​insertion

​Frameshift Mutation: insertion or deletion of a nucleotide in the DNA sequence

shift the entire sequence

​Point Mutation Example:

THE CAT ATE THE RAT - each 3 letter word represents a codon

THE CAT ATE THE MAT - substituting letter "R" with "M", did not affect the sequence of sentence.

Frameshift Mutation Example:

THE CAT ATE THE RAT - each 3 letter word represents a codon

THE ATA TET HER AT - deleting letter "C" from the sentence made

entire sentence incoherent.

Multiple Choice

Any change in the sequence of DNA nucleotides is called a —

• transgenic shift

• monohybrid trait

• single genotype

• mutation

Multiple Choice

A mutation that inserts or deletes a nucleotide is called a _____________

• Frameshift mutation

• Point Mutation

Multiple Choice

A mutation that substitutes a nucleotide for another is called a _____________

• Frameshift mutation

• Point Mutation

Multiple Choice

Following is an example of what type of mutation?

• Frameshift mutation

• Point mutaiton

Multiple Choice

Following is an example of what type of mutation?

• Frameshift mutation

• Point mutaiton

Q19

Which mutation would have the most significant impact on the gene product?

Why would the impact be so significant?

​Mutations in somatic cells - affect only the organism

Mutations in germ cells - passed on to offspring

occurs when a chromosome breaks and the (typically two) fragmented pieces re-attach to different chromosomes

​

Translocation Mutation

Multiple Choice

Q5: The diagram shows a type of chromosomal mutation.

What type of mutation is shown?

• Deletion

• Insertion

• Duplication

• Translocation

Multiple Choice

Which statements explain how a mutation in a somatic cell is different from a mutation that occurs in gametes?

• Somatic cell mutations occur in cells that give rise to gametes.

  Gamete mutations occur in cells that result in apoptosis.

• Somatic cell mutations are maintained in the gene pool.

  Gamete mutations are expelled from the gene pool.

• Somatic cell mutations are generally not passed to offspring.

  Gamete mutations are usually passed to offspring

• Somatic cell mutations will not be expressed by the individual that contains the mutation.

  Gamete mutations will be expressed by the individual.

Know the important events of Meiosis, their significance and the key differences between Meiosis I and Meiosis II

I Will...

Review the process of Meiosis and its significance to sexual reproduction

We Will...

Win for the Day!

​Homologous pairs - 2 chromosomes (one from mom, one from dad) that have the same length and general appearance

Diploid (2n) - cell has TWO copies of each chromosome (1 from each parent)

46 chomosomes

Haploid (n) - has ONE copy of each chromosome

22 autosomes and 1 sex chromosome

sperm (x or y)

egg (always x)

​Diploid (2n)

​Haploid (n)

​(through DNA replication)

​homologous chromosomes = 2 sister chromatids

1 sister chromatid = duplicated chromosomes

​Haploid (n)

​Haploid (n

​chromatid

​0

​

​Sister Chromatids

Multiple Choice

During which stage does the process of Crossing-over occur?

• During the completion of Meiosis II

• Prophase of Meiosis I

  (Prophase I)

• During the start of Meiosis II

• Prophase of Meiosis II

  (Prophase II)

Multiple Choice

A diploid cell contains __ chromosomes, while a haploid cell contains __ chromosomes.

• 46 ; 46

• 46 ; 23

• 23 ; 46

• 23 ; 23

Multiple Choice

Q26: A cell undergoing a biological process is shown.

Which process occurs between Step 2 and Step 3 and creates more genetic diversity in the resulting cells?

• Chromosome nondisjuction

• genome replication

• crossing over

• chromosomal deletion

Know how to complete a punnet square, and calculate the probabilities and ratios of the genotypes.

I Will...

Learn how to use punnet squares to calculate possible outcomes of genotypes

​We Will...

Win for the Day...

Drag and Drop

A person's ​

Placeholder

is their unique sequence of DNA. ​

Placeholder

is the detectable expression of this genotype – a patient's clinical presentation

Drag these tiles and drop them in the correct blank above

Genotype

Phenotype

Match

Match the following vocabulary terms

• dominant

• recessive

• genotype

• phenotype

always seen

masked by dominant

organism's collection of genes

organism's observable traits

• always seen

• masked by dominant

• organism's collection of genes

• organism's observable traits

Match

Match the following vocabulary terms

• homozygous

• heterozygous

• alleles

• meiosis

2 of the same alleles

2 different alleles

genes in alternate forms

cell division to create gametes

• 2 of the same alleles

• 2 different alleles

• genes in alternate forms

• cell division to create gametes

Match

Match the following Genotypes with their examples

• Homozygous Dominant

• Homozygous Recessive

• Heterozygous

BB

bb

Bb

• BB

• bb

• Bb