NSC Life Sciences DNA: The Code of Life: 1.1
Various options are provided

Question

1.1
Various options are provided as possible answers to the following questions. Choose the correct answer and write only the letter (A to D) next to the question number, for example (1.1.1 to 1.1.10 in the ANSWER BOOK).

1.1.1 Which ONE of the following combinations results in genetic variation in organisms?
A Mitosis; asexual reproduction; mutations
B Mitosis; sexual reproduction; mutations
C Mitosis; meiosis; sexual reproduction
D Meiosis; sexual reproduction; mutations

1.1.2 The inheritance of one trait does not depend on the inheritance of another trait. This represents...
A Mendel's law of dominance.
B The law of codominance.
C The principle of variation.
D The principle of independent assortment.

1.1.3 In bees, females are diploid and males are haploid. Females and males produce haploid gametes. This means that...
A females produce gametes by mitosis.
B females produce gametes by meiosis.
C males produce gametes by mitosis.
D males produce gametes by meiosis.

1.1.4 In mice, the genotype for producing grey fur and Yy produces yellow fur. The genotype YY results in death during the early development. A yellow mouse is mated with a yellow mouse. Which combination of the above mice can produce offspring that can be born alive?
A 1 : 1
B 2 : 1
C 3 : 1
D None

1.1.5 The diagram below shows crossing over.

Which ONE of the combinations of alleles would be present in chromatid C after crossing over occurred at point P?
A aAbB
B abBB
C aBrt
D ABrt

1.1.6 The diagram below shows the blood types of two parents.

The only possible blood type(s) of the offspring of the first generation (F1) is/are...
A AB and O.
B A only.
C B only.
D A and B.

1.1.7 The structure of DNA was determined by using X-ray pictures produced by...
A Watson and Crick.
B Franklin and Wilkins.
C Mendel and Darwin.
D Hershey and Chase.

1.1.8 Brown eye colour in humans is dominant over blue eye colour. A man with brown eyes marries a woman with blue eyes. They have a son with brown eyes and a daughter with blue eyes.

We can conclude that...
A the man is the father of the children.
B the man is heterozygous for eye colour.
C the colour gene is sex-linked.
D both parents are heterozygous.

1.1.9 A possible explanation for an observation that can be tested is known as a...
A fact.
B law.
C theory.
D hypothesis.

1.1.10 Common structural characteristics between groups of dinosaurs were used to construct the phylogenetic tree below.

The two groups of dinosaurs with the most characteristics in common are...
A Triceratops and Ptychophalosaurus.
B Parasaurolophus and Triceratops.
C Stegosaurus and Parasaurolophus.
D Plateosaurus and Stegosaurus.

1.2 Give the correct biological term for each of the following descriptions. Write only the term next to the question number (1.2.1 to 1.2.10) in the ANSWER BOOK.

1.2.1 The type of inheritance where the dominant allele has the expression of the recessive allele in the heterozygous condition.

1.2.2 The process by which genetically identical organisms are formed using biotechnology.

1.2.3 A group of organisms of the same species in a specific habitat.

1.2.4 The type of vision shared by apes and humans that allows for depth perception.

1.2.5 A group that includes the genera Homo and Pan.

1.2.6 A human disorder caused by non-disjunction of chromosome 21.

1.2.7 The site of protein synthesis during which mRNA forms from DNA.

1.2.8 Structures in different organisms that have a similar basic plan which suggests that they share a common ancestor.

1.2.9 The position of a gene on a chromosome.

1.2.10 The type of variation in a population with no intermediate phenotypes.

1.3 Indicate whether each of the statements in COLUMN I applies to A ONLY, B ONLY, BOTH A AND B, or NONE. Write only the letter next to the statement number (1.3.1 to 1.3.3).

1.3.1 The size and colour of fruit in a plant species is genetically controlled. The allele for fruit (B) is recessive to the allele for bright fruit (B). The allele for yellow fruit (b) is recessive to the allele for green fruit (G).

1.4.1 State:

(a) The phenotype of the plant with the genotype BbGg
(b) ALL possible genotypes of the gametes produced by the plant mentioned in QUESTION 1.4(a).

1.4.2 In a cross between two plants with genotypes BBGG and bbgG, what percentage of the offspring will be homozygous for both traits?

1.5 The diagrams below show different phases in meiosis.

1.5.1 Label structures W and X.

1.5.2 How many chromosomes are present in each cell in:

(a) Phase A
(b) Phase C

1.5.3 Give only the LETTER of the diagram that represents anaphase II.

1.5.4 State the function of structure Y and structure Z.

1.5.5 Identify phase C.

1.1 Various options are provided as possible answers to the following questions - NSC Life Sciences - Question 1 - 2016 - Paper 2

Worked Solution & Example Answer:1.1 Various options are provided as possible answers to the following questions - NSC Life Sciences - Question 1 - 2016 - Paper 2

1.1.1 Which ONE of the following combinations results in genetic variation in organisms?

1.1.2 The inheritance of one trait does not depend on the inheritance of another trait. This represents...

1.1.3 In bees, females are diploid and males are haploid. Females and males produce haploid gametes. This means that...

1.1.4 In mice, the genotype for producing grey fur and Yy produces yellow fur. The genotype YY results in death during the early development. A yellow mouse is mated with a yellow mouse. Which combination of the above mice can produce offspring that can be born alive?

1.1.5 The diagram below shows crossing over. Which ONE of the combinations of alleles would be present in chromatid C after crossing over occurred at point P?

1.1.6 The diagram below shows the blood types of two parents. The only possible blood type(s) of the offspring of the first generation (F1) is/are...

1.1.7 The structure of DNA was determined by using X-ray pictures produced by...

1.1.8 Brown eye colour in humans is dominant over blue eye colour. A man with brown eyes marries a woman with blue eyes. They have a son with brown eyes and a daughter with blue eyes. We can conclude that...

1.1.9 A possible explanation for an observation that can be tested is known as a...

1.1.10 Common structural characteristics between groups of dinosaurs were used to construct the phylogenetic tree below. The two groups of dinosaurs with the most characteristics in common are...