2.1 In rabbits, black fur is produced by the allele (B) and white fur by the allele (b) - NSC Life Sciences - Question 2 - 2016 - Paper 2
Question 2
2.1 In rabbits, black fur is produced by the allele (B) and white fur by the allele (b).
The table below shows the genotypes of some rabbits.
| RABBIT | GENOTYPE |... show full transcript
Worked Solution & Example Answer:2.1 In rabbits, black fur is produced by the allele (B) and white fur by the allele (b) - NSC Life Sciences - Question 2 - 2016 - Paper 2
Step 1
2.1.1 What is the phenotype:
(a) Produced by the recessive allele
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The phenotype produced by the recessive allele (b) is white fur.
Step 2
2.1.1 What is the phenotype:
(b) of rabbit 2
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The phenotype of rabbit 2, which has the genotype Bb, is black fur.
Step 3
2.1.2 Give the NUMBER only (1, 2 or 3) of the rabbit(s) that is/are:
(a) Pure-bred
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The NUMBER of pure-bred rabbit(s) is 1.
Step 4
2.1.2 Give the NUMBER only (1, 2 or 3) of the rabbit(s) that is/are:
(b) Homozygous dominant
98%
120 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The NUMBER of homozygous dominant rabbit(s) is 1.
Step 5
2.1.3 Use a genetic cross to show the percentage chance of rabbits 1 and 3 having offspring with white fur.
97%
117 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
To determine the percentage chance of rabbits 1 (BB) and 3 (bb) having offspring with white fur, we can represent the genetic cross as follows:
P1:Phenotype: Black×White\text{Gametes:}
B \, B \
b \, b \Offspring genotype:BbBbBbBb
All offspring will have the genotype Bb, which results in a phenotype of black fur. Thus, percentage chance of white fur offspring is 0%.
Step 6
2.2.1 Give ONE conclusion the scientists came to after the investigation.
97%
121 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The two types of shrimp, type A and type B, did not belong to the same species.
Step 7
2.2.2 Explain your answer to QUESTION 2.2.1.
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Individuals that belong to the same species can interbreed, whereas the two types of shrimp were unable to interbreed, indicating they are different species.
Step 8
2.2.3 Why did the scientists repeat the investigation?
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The scientists repeated the investigation to ensure the results would be reliable and consistent across multiple trials.
Step 9
2.3 Describe how speciation occurs through geographic isolation.
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Speciation through geographic isolation occurs when an original population is separated into two populations by a geographic barrier. This separation results in no gene flow or interbreeding between the populations. Each population evolves independently due to different environmental conditions, allowing natural selection to act on them over time. Eventually, these populations may become so genetically distinct that even if they were to come in contact again, they would be unable to reproduce with each other.
Step 10
2.4.1 How could the validity of this investigation be increased?
98%
120 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The validity of the investigation could be increased by ensuring ponds 1 and 2 have identical environmental conditions and by including equal numbers of predatory fish in both ponds.
Step 11
2.4.2 Identify the:
(a) independent variable
97%
117 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The independent variable is the type of predator introduced.
Step 12
2.4.2 Identify the:
(b) dependent variable
97%
121 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The dependent variable is the number of spots on the guppies.
Step 13
2.4.3 Explain why the scientist included pond 2 in this investigation.
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Pond 2 was included as a control to compare the results with pond 1, ensuring that any changes observed were due to the presence of the predator as an independent variable.
Step 14
2.5.1 What is this type of diagram called?
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
This type of diagram is called a phylogenetic tree.
Step 15
2.5.2 How many genera are shown in the diagram above?
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
There are 4 genera shown in the diagram above.
Step 16
2.5.3 According to this diagram, which:
(a) Genus is most recently evolved
98%
120 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The genus most recently evolved is Homo.
Step 17
2.5.3 According to this diagram, which:
(b) Genus is the oldest
97%
117 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The genus that is the oldest is Ardipithecus.
Step 18
2.5.3 According to this diagram, which:
(c) Hominid share a common ancestor with Australopithecus africanus
97%
121 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The hominid that shares a common ancestor with Australopithecus africanus is Paranthropus species.
Step 19
2.5.4 Give ONE example of an Australopithecus africanus fossil found in South Africa.
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
One example of an Australopithecus africanus fossil found in South Africa is Mrs. Ples.
Step 20
2.5.5 Name TWO Homo species, besides Homo sapiens, that were found in Africa.
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Two Homo species found in Africa, besides Homo sapiens, are Homo habilis and Homo erectus.
