Various options are provided as possible answers to the following questions - NSC Life Sciences - Question 1 - 2022 - Paper 2
Question 1
Various options are provided as possible answers to the following questions. Choose the answer and write only the letter (A to D) next to the question number in the ... show full transcript
Worked Solution & Example Answer:Various options are provided as possible answers to the following questions - NSC Life Sciences - Question 1 - 2022 - Paper 2
Step 1
1.1.1 The components of a DNA molecule that provide the code for protein synthesis are the ...
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 components of a DNA molecule that provide the code for protein synthesis are the D. nitrogenous bases. These bases, which include adenine (A), thymine (T), cytosine (C), and guanine (G), pair specifically to encode the genetic information necessary for protein synthesis.
Step 2
1.1.2 During which stage of meiosis do spindle fibres begin to form?
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
Spindle fibres begin to form during A. Prophase of meiosis. During this stage, chromatin condenses into visible chromosomes and spindle fibres emerge from the centrosomes.
Step 3
1.1.3 An individual has Down syndrome, in the karyotype there is an abnormal number of chromosomes at chromosome pair ...
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
An individual with Down syndrome has an abnormal number of chromosomes at chromosome pair C. 21. This condition is caused by trisomy 21, where there are three copies of chromosome 21.
Step 4
1.1.4 An individual that has received an identical allele from each parent is described as being ...
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
An individual that has received an identical allele from each parent is described as being A. homozygous. This means that both alleles at a particular gene locus are the same.
Step 5
1.1.5 A plant species has a diploid chromosome number of 12. Which ONE of the following is the haploid chromosome number?
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
For a plant species with a diploid chromosome number of 12, the haploid chromosome number is C. 6. This is calculated by dividing the diploid number by two (12/2 = 6).
Step 6
1.1.6 Inheritance by multiple alleles in genetics refers to ...
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
Inheritance by multiple alleles refers to D. traits that influence two or more characteristics. In this type of inheritance, more than two alleles exist for a gene within a population, affecting the traits expressed.
Step 7
1.1.7 Which ONE of the following is a reproductive isolation mechanism?
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
A reproductive isolation mechanism is A. Breeding at the same time of the year. This mechanism prevents different species from mating by timing their reproductive cycles.
Step 8
1.1.8 Normal humans over have ...
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
Normal humans have B. 23 autosomes and an X chromosome in females or C. 22 autosomes and a Y chromosome in males. Each human cell typically contains 22 pairs of autosomes plus two sex chromosomes.
Step 9
1.1.9 Which ONE of the following occurs in mitosis but NOT in meiosis?
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
In mitosis, A. Two cells are formed at the end of the division. This is distinct from meiosis, which results in four genetically different cells.
Step 10
1.1.10 The graph below shows the percentage similarity between human (Hu) DNA and the DNA of some species of African apes.
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
To determine the best phylogenetic tree, one must analyze the similarity percentages. Based on the graph, the tree that best represents the information is likely C. [Tree C], as it follows the similarity trends as shown.
