Review 2

Review 2

Cell Cycle & Genetics

Asexual Reproduction

• A single parent produces one or more offspring by dividing into two cells.

• Mitosis is asexual reproduction.

• Offspring are clones of the parents.

• Mitosis includes PMAT, which is prophase, metaphase, anaphase, telophase

Cell Cycle

• Before a cell goes through mitosis, it must complete interphase

• Interphase includes, G1, S, and G2

• During G1, the cell grows in size

• During S, the DNA is replicated

• During G2, the cell grows in size

• After completing interphase, the cell will move into MITOSIS or M phase. This is when PMAT occurs.

PMAT

Prophase: nuclear envelope dissolves; DNA condenses into chromosomes

Metaphase: chromosomes line up in the middle of the cell

Anaphase: chromosomes are pulled by the spindle fibers to opposite ends of the cell

Telophase: chromosomes are on opposite sides of the cell; the cell begins to divide into two cells

Multiple Choice

In mitosis, the two resulting cells are

• different from the starting cell and identical to each other.
• different from the starting cell and different from each other.
• identical to the starting cell and different from each other.
• identical to the starting cell and identical to each other.

Multiple Choice

The phase in mitosis where chromosomes move away and are pulled apart by spindles to opposite sides of the cell.

• prophase
• anaphase
• metaphase
• telephase

Multiple Choice

Chromosomes condense from long stands into rod like structures. 

• Prophase
• Interphase

Multiple Choice

Which is Metaphase?

• A
• E
• C
• F

Multiple Choice

• Cytokinesis
• Anaphase
• Telophase
• Prophase

Multiple Choice

• Anaphase
• Cytonkinesis
• Interphase
• Prophase

Multiple Choice

• Cytokinesis
• Interphase
• Anaphase
• Metaphase

Multiple Choice

• Anaphase
• Cytokinesis
• Telophase
• Metaphase

Sexual Reproduction

• The fusion of gametes to create a genetically unique cell.

• Gametes are formed from MEIOSIS.

• Meiosis creates genetic variation.

• Meiosis requires PMAT twice.

• 4 unique daughter cells are produced.

Multiple Choice

What is one of the advantages, of reproducing sexually versus asexually?

• survival of the fittest
• overproduction
• genetic variation
• cloning

Multiple Choice

How many daughter cells are produced at the end of meiosis?

• 1
• 2
• 3
• 4

Multiple Choice

How many daughter cells are produced at the end of mitosis?

• 1
• 2
• 3
• 4

Multiple Choice

Asexual reproduction and mitosis occur in...

• Body Cells
• Sex Cells or Gametes

Multiple Choice

Compared to the number of chromosomes contained in a body cell, how many chromosomes would normally be contained in a gamete?

• The same number
• One-fourth as many
• Twice as many
• Half as many

Multiple Choice

A male shark has 40 chromosomes in each of its sex cells. How many would be present in its body cells?

• 20
• 40
• 80
• 160

Multiple Choice

MITOSIS

• INCREASES GENETIC VARIATION

• ALLOWS TRAITS TO BE PASSED ON TO OFFSPRING

• PRODUCES 2 IDENTICAL DAUGHTER CELLS

• ALL ARE TRUE

Genetics Review

Genotypes & Phenotypes

• Genotypes are the alleles inherited from each parent. We represent them with letters.

• Phenotypes are the physical representation of the alleles you inherit from your parents. We can see your phenotype.

• Heterozygous means one uppercase letter and one lowercase letter

• Homozygous dominant means two uppercase letters.

• Homozygous recessive means two lowercase letters.

Multiple Choice

Which of the following genotypes is heterozygous?

• Bb
• BB
• bb
• B

Multiple Choice

What does heterozygous mean?

• An organism that has the same genes for a trait (TT or tt)
• An organism that has different genes for a trait (Tt)
• When neither gene is fully dominant; offspring is a mixture of both
• the different forms of a trait (hair color--> brown, blonde, red

Multiple Choice

Which of the following is a phenotype?

• Aa
• black hair
• heterozygous genes
• mutated DNA

Multiple Choice

In the punnett square shown, what must the genotype of the missing parent be?

• BB
• Bb
• bb
• Tt

Multiple Choice

B = brown fur  b = white fur
In the punnett square, what is the probability for white fur? 

• 0%
• 25%
• 50%
• 75%

Multiple Choice

T - tall and t = short
In the punnett square below, what belongs in the missing square

• tt
• Tt
• Bb
• TT

Multiple Choice

In a heterozygous genotype, the ___________ allele takes over in the phenotype.

• recessive
• dominant
• lower case letter
• both 

Multiple Choice

Heterozygous is when...

• the alleles are the same
• the alleles are different
• the alleles are absent
• the alleles are present

Multiple Choice

Homozygous is when...

• the alleles are the same
• the alleles are different
• the alleles are absent
• the alleles are present

Incomplete Dominance

• The dominant allele is not fully dominant over the recessive allele. This means, when an organism inherits one of each (1 dominant & 1 recessive) the phenotype is a mixture of the two.

  
  

  Example: Red petals are incompletely dominant over white flowers. This means if a flower inherits one of each, the petals will be pink. 

Codominance

• Two dominant alleles are equally strong. They both will take over the recessive allele, but if they are inherited together, one is not stronger than the other is. This means, if an organism inherits both dominant alleles, they will express both traits equally.

  
  

• Blood type is codominant. Type A and Type B are codominant to each other. O is recessive.

Sex-Linked Inheritance

• Sex-linked or X-linked genes are only inherited on the X chromosome.

  Male = XY  Female = XX

  Because X-linked genes are only inherited from the X chromosome, we only write the superscript on the X.

  Example:

  X^HY Normal Man

  X^hY Man with Hemophilia

  X^HX^h Carrier Female; no disease

  X^HX^H Normal Female

  X^hX^h Female with Hemophilia

Multiple Choice

Look at this cross: X^BX^b x X^BY

What proportion of the male children are colorblind?

• 100%

• 75%

• 50%

• 25%

Multiple Choice

Look at this cross: X^B X^B x X^b Y

What proportion/percent of the male children are colorblind?

• 100%

• 75%

• 25%

• 0%

Multiple Choice

In fruit flies, eye color is a sex linked trait. Red (R) is dominant to white (r). What is the sex and eye color of flies with the following genotype: X ^R Y ?

• male with white eyes

• female with white eyes

• male with red eyes

• female with red eyes

Multiple Choice

In fruit flies, eye color is a sex linked trait. Red (R) is dominant to white (r). What is the sex and eye color of flies with the following genotype: X ^R X ^r ?

• male with white eyes

• female with red eyes

• male with red eyes

• female with white eyes

Multiple Choice

In mice coat color is incompletely dominant. Black and white are homozygous. Brown mice are heterozygous.

What is the genotype for a brown mouse?

• BB

• Bb

• bb

Multiple Choice

Some flowers are controlled by codominance. Red flowers (RR), blue flowers (BB) and Speckled flowers (RB).

Cross a red flower with a blue flower.

• 1 red, 2 speckled, 1 blue

• 2 red, 2 blue

• 4 speckled

• 1 red, 1 speckled, 2 blue

Multiple Choice

Some flowers are controlled by codominance. Red flowers (RR), blue flowers (BB) and Speckled flowers (RB).

Cross two speckled flowers.

• 1 red, 2 speckled, 1 blue

• 2 red, 2 blue

• 2 blue, 2 speckled

• 1 red, 1 speckled, 2 blue

Multiple Choice

Some flowers are controlled by codominance. Red flowers (RR), blue flowers (BB) and Speckled flowers (RB).

Cross a red flower with a speckled flower. What is the phenotypic ratio?

• 2 red, 2 speckled

• 2 red, 2 blue

• 2 blue, 2 speckled

Multiple Choice

When one allele is not dominant over the other, resulting in both traits expressed in a heterozygous individual.....

• Incomplete Dominance

• Codominance

Multiple Choice

When one allele is not dominant over another, resulting in a blended phenotype for heterozygous offspring is considered....

• Incomplete Dominance

• Codominance