Question

1) Describe how chromosomes and genes are related. (3 points)


2) What is the difference between a haploid species and a diploid species? (3 points)


3. a) What is the difference between a genotype and a phenotype? (3 points)



b) Give one reason why it is difficult to exactly predict someone’s traits, even if you know their genotype. (3 points)



4) Name two ways that mitosis and meiosis are similar. (8 points)



5) Name two ways asexual reproduction can be an advantage for a species, over sexual reproduction. (6 points)



6) Mendel performed his experiments with thousands of pea plants. How did this make his probability calculations more reliable? (4 points)



7) In humans, having wet earwax is a dominant trait. Having dry earwax is recessive.



a) A man has two recessive alleles. What is his phenotype? (2 points)


b) A woman has two recessive alleles. What is her phenotype? (2 points)



c) If this man and woman have a child, is it possible for their child to have wet earwax? Explain. (4 points)


8. Having dimples is a dominant trait. Having no dimples is recessive.


a) A father has the genotype Dd and a mother has the genotype dd. Fill in the Punnett square below to show their possible offspring. (6 points)


b) Describe the genotype ratio for their offspring. (2 points)


c) Describe the phenotype ratio for their offspring. (2 points)


d) If they have a child, what is the probability of their chi

Answer 1

1.) Genes are made up of chromosomes and chromosomes are built from genes. Both direct the construction of DNA.
2.) A haploid species is comprised members with one complete set (half the amount) of chromosomes. A diploid species is comprised of members with 2 complete sets of chromosomes(have a full set of chromosomes.).
3a.) A genotype is the makeup of the DNA of a living organism. A phenotype is the set of characteristics (traits) of a living organism. 3b.) Because that person's traits depend on the way they are expressed and on their environment.
4.) Mitosis and Meiosis both are a kind of cellular division and are both used in a type of reproduction( one process is used in either one of two types of reproduction.)

5.) Little to no harmful genetic mutations are produced (offspring is identical to parents). 2) Helpful traits are passed on to offspring.
6.) The pea plants produce many offspring, can fertilize themselves and have varieties in genotype and phenotype ( different DNA structures and different traits.).
7a.) Homozygous recessive is the phenotype of the man with 2 recessive alleles. 7b.) Homozygous recessive is the woman's phenotype. 7c.) If these two people were to have a child it would be impossible for their child to have wet earwax. Both parents have 2 RECESSIVE alleles which represent having dry earwax, so each parent has 50% of the dry earwax trait. If the child were to have wet earwax, its parents would have 2 dominant alleles representing the trait of wet earwax. But if the parents didn't care about what texture of earwax their child had, they would both need to have 1 dominant and 1 recessive allele ( Dominant alleles represent wet earwax.) (Recessive alleles represent dry earwax.)
8a.) First Column( Dd)
d∫  Dd
d∫  Dd

Second Column( D d/ horizontal) ( d d /vertical)

Top Right: d d
Bottom Right: d d

8b.) Mother/Father offspring Genotype Ratio: 1:1 (0.5 both parents)
Top Left:Dd
Bottom Left: Dd

Top Right: dd
Bottom Right: dd

KEY: D= FATHER
d=MOTHER

8c.) Phenotype ratio for their offspring is 1:1 ( there is a possibility that the offspring would have one of these traits. Might or might not have dimples. Phenotype is not definite.

8d.) The probability of their child having dimples is 50% chance.

Ratios: 1:1 means Dimples: No Dimples.