Mutations
What is a mutation?
A change in the genetic code.
The physical trait, how something looks is called
Phenotype
What are the phenotypic percentages of a cross of two parents that are homozygous recessive (gg).
G- green
g- yellow
100% yellow
Two kittens are raised with similar environmental conditions (same amount of food, water, and space). How do they look different?
Different genetic factors
What is an advantage of sexual reproduction?
Genetic variation
How does a change in the genetic code change the phenotype?
The two allele "code"
Genotype
What are the phenotypic ratios of offspring black fur to white fur between a homozygous recessive white fur parent to a heterozygous black fur parent.
B- black fur
b- white fur
2:2
After watching a video of animals running, a class becomes especially interested in how racehorses can sprint so fast. They interview a racehorse owner who says a baby racehorse might become a champion sprinter one day.
The students collect data on one of the baby racehorse’s parents as it goes from resting to sprinting. They collect data in a table to show how different physiological factors change during the horse’s rest, start, and sprint phases.
How did the horse owner know that the baby horse was likely to become a successful racehorse?
The baby horse has parents that were very fast and inherited traits from both, making it likely to be fast too.
A person notices that a loaf of bread in the kitchen is covered in mold. The bread didn't have any visible mold the previous morning. The person knows that mold can reproduce either sexually or asexually.
Which reason best describes the mold that quickly covered the bread overnight?
The mold most likely reproduced asexually and the offspring are genetically identical.
Sickle cell anemia is a mutation in which the red blood cells change to a sickle (banana) shape instead of the round shape. Sometimes this can cause blood clots. What type of mutation is this?
Harmful
What do genes on a chromosome code for?
Protein
If Jessica has light eyes (bb) and both of her parents have dark eyes (Bb) how is this possible?
Jessica received the recessive allele from both parents.
A mutation in a type of butterfly causes some individuals to have a spotted wing pattern. A butterfly with this mutation resting on the trunk of a tree blends in. How is this mutation beneficial to the butterfly?
The mutation provides the butterfly with camouflage that increases its survival rate.
Why does a Punnett Square not work for asexual reproducing organisms?
The offspring are genetically identical.
If two mutations were to occur in two locations of a lizard (1) the skin cells to make the skin blue and (2) the eggs to make the tail shorter. Which mutation(s) would be passed to the offspring and why?
The tail mutation found in the gametes.
Fill in the blanks:
Chromosomes- ______- Protein- ______- Phenotype
Genes, protein function
What are the genotypic ratios of a cross between two heterozygous tall (Tt) parents?
TT- 1/4
Tt- 2/4
tt- 1/4
Chickens release ammonia in their waste. If the waste is not managed in houses used in chicken farming, the chickens can be affected. The table shows how increased ammonia levels affect the body weight of chickens.
Ammonia Level Body Weight
0 6.74
25 6.55
50 6.24
75 6.03
Based on the data, how would the body weight of chickens change if the ammonia level reaches 100 ppm?
It would decrease; an increase in ammonia levels harms chickens.
The genome of a goldfish has 96 chromosomes. How many chromosomes are given by one parent?
48, half
A particular allele is lethal in homozygotes. However, heterozygotes develop normally. Why does this allele remain in the population?
The recessive allele is masked in heterozygotes.
How does an organism "get" its physical trait?
Chromosomes given through parents' gametes have genes that code for a protein that performs a function as seen as the phenotype.
In fruit flies, the allele for red eyes (R) is dominant and the allele for sepia eyes (r) is recessive. A female fly has red eyes. How can you determine the female's genotype?
Mate the female with a male with sepia eyes. If any of their offspring have sepia eyes, she is heterozygous Rr.
Amanda is preparing her garden for the summer. Which factors can affect the growth of her vegetables?
genetics or environment (sunlight, water, air circulation, bugs, etc)
In Ireland people relied on the main crop of potatoes. How is it possible that all potatoes in the country were affected by blight (a fungus) that lead to the Irish potato famine?
Potatoes are asexual and genetically identical and all are affected.