Download Tic Tac Toe 1 - Northwest ISD Moodle

Tic Tac Toe 1
1. Going from a 2n cell to cells with ‘n’ is called?
ANSWER: Meiosis, going from a diploid cell (2 of each chromosome) to sex cells (one of each
chromosome)
2. If a boy is colorblind, which parent did he inherit it from? Explain your answer. And remember
colorblindness is X-linked and recessive
ANSWER: Mother, because the son has to inherit their X chromosome from their mom and
colorblindness is X-linked.
3. A typical gene has how many alleles?
ANSWER: 2
4. Two identical alleles for the same trait are called?
ANSWER: Homozygous
5. What are karyotypes used for?
ANSWER: (Karyotypes are pictures of chromosomes) Used to count chromosomes and make sure
they are shaped correctly
6. How does crossing over cause genetic variation?
ANSWER: It mixes up a person’s genes on their homologous chromosomes, so babies from the same
people can get a variety of different allele combinations.
7. How does Co-Dominance inheritance work?
ANSWER: Both alleles are dominant and expressed equally in the phenotype (like a black and white
feathered chicken)
8. If a heterozygous A blood genotype is crossed with a heterozygous B genotype, what is the
genotypic ratio of the offspring?
ANSWER: 1:1:1:1 (one AB, one heterozygous A, one heterozygous B, and one O)
9. What is fertilization?
ANSWER: When two sex cells unite
10. What is it called when chromosomes don’t separate properly during meiosis (during Anaphase)?
ANSWER: Non-disjunction
11. If you see a prime next to an allele (R’), what type of inheritance is in play?
ANSWER: Incomplete dominance
12. Can O positive blood give to AB negative? Explain.
ANSWER: No, a positive blood cell has a special molecule on the outside only recognized by other
positive bloods. O negative, AB negative, A negative, and B negative can give blood to AB negative.
13. What is the purpose of Meiosis?
ANSWER: to create sex cells
14. Why is it easier for a male to inherit an X-linked recessive disorder?
ANSWER: Because males only have one X chromosome, so they only have to inherit one recessive
allele and they have the recessive phenotype.
15. Patterned spiders are dominant. A plain spider is crossed with a homozygous dominant patterned
spider. What percentage of offspring is expected to be patterned? Why?
ANSWER: 100%, because each spider offspring will have a dominant allele from the patterned
parent…making them heterozygous and showing the dominant phenotype (Pp)
Tic Tac Toe 2
1. What are alleles?
ANSWER: Alternate forms (variations) of a gene, Example: Brown eyes, Green eyes, Blue eyes
2. Two rabbits are crossed. Tan fur is dominant over white fur. 50% of the are tan and 50% are white.
What are the genotypes of the parents?
ANSWER: Tt and tt
3. If you cross someone with O blood with someone with AB blood, what is the phenotypic ratio?
ANSWER: 2:2 (Two A blood, Two B blood)
4. Hemophilia is X-linked and Recessive. How does a female inherit hemophilia?
ANSWER: She has to inherit a recessive allele from both her mom and her dad
5. What is crossing over?
ANSWER: When the homologous chromosome pairs exchange genes before sex cells are made (sperm or
eggs). This ‘mixes up’ what you can pass down to your offspring.
6. If two heterozygous tall plants are crossed, what is the phenotypic ratio of their offspring?
ANSWER: 3:1 (Three are tall and one in short)
7. If a trait is ‘autosomal’, what does that mean?
ANSWER: that it is inherited on chromosomes 1-22 (not on a sex chromosome)
8. If a child has type B blood and the Mom has type A, what are the father’s genotype possibilities?
ANSWER: AB, BB, or BO
9. What are three human traits that are polygenic?
ANSWER: height, hair color, eye color, skin color
10. A couple has 8 girls…what is the probability that their next kid will be a girl?
ANSWER: 50%, every time you have a child it is a 50/50 chance of having a boy or girl
11. Can someone with O negative blood give to someone with O positive? Explain.
ANSWER: Yes, O negative is the universal donor because it does not have any indicator molecules on the
outside of the blood cells at all and therefore can give to anyone
12. Define the Law of Segregation.
ANSWER: When gametes are made, the alleles for a gene are separated into different sex cells. For
instance, a person with genotype Aa…some sex cells will have A and some sex cells will have a.
13. Which types of cells have at least one sex chromosome?
ANSWER: All cells…diploids will have two sex chromosomes and haploids only have one sex
chromosome
14. What does meiosis begin and end with? BE SPECIFIC
ANSWER: It begins with 1 diploid cell and ends with 4 genetically different haploid cells
15. In fruit flies, the gene for eye color is located on the X chromosome. The red eye allele (R) is
dominant to the white eye allele (r). A heterozygous female fly is mated with a red-eyed male fly. What is
their expected offspring percentages?
ANSWER: 25% homozygous dom female, 25% heterozygous female, 25% Red eyed male, 25% white
eyed male