EduNinja• State that chromosomes are made of DNA, which contains genetic information in the form of genes
A gene is responsible for the production of lycopene in fruits. Geneticists have recently produced genetically modified pink pineapples using the gene associated with the production of lycopene.
Genes are found at specific locations on an important biological molecule.
State the name of this biological molecule.
A scientist investigated sexual reproduction in flowering plants.
Fig. 2.1 shows the procedure for crossing two plants of the same species.
The scientist collected the seeds and germinated them. The leaves and flowers of the offspring plants showed phenotypic variation as they were not all identical to the parent plants.
The scientist then investigated the chromosomes of all the offspring plants and found that they had exactly the same number of chromosomes as the parent plants.
Define the term chromosome.
Apple scab is a disease that infects apple trees.
Fig. 3.1 shows apples from uninfected and infected apple trees.
Fig. 3.1
There is a gene that determines whether or not apple trees are resistant to apple scab disease.
There are two alleles for this gene:
- disease-resistant, R
- not disease-resistant, r
Complete the sentence.
Genes and alleles are made of
Fig. 5.1 shows the stages involved in protein synthesis.
Fig. 5.1
State the names of the parts labelled X, Y and Z in Fig. 5.1.
X
Y
Z
What is defined as 'a thread-like structure of DNA, carrying genetic information in the form of genes'?
allele
chromosome
protein
zygote
Fig. 5.1 shows some of the stages in the reproduction of the bacterium Escherichia coli.
Fig. 5.1
Complete the sentences about the cells in Fig. 5.1.
The DNA is in the form of a double The DNA is copied so that the number of loops of DNA after cell division is in each daughter cell. The daughter cells are genetically to the original cell.