1.5 The origin of cells [91 marks]
1. Which cell component arose first during the formation of the earliest [1 mark]
cells?
A. Chloroplast
B. Plasma membrane
C. Mitochondria
D. Cell wall
2. In the chimpanzee (Pan troglodytes), the haploid number of chromosomes[1 mark]
is 24. How many sister chromatids are present in the G2 phase of a
somatic cell, such as a cell in the bone marrow of the chimpanzee?
A. 12
B. 24
C. 48
D. 96
,3. Pasteur used swan-necked flasks and a nutrient broth to demonstrate [1 mark]
that spontaneous generation of organisms does not occur on Earth. Some
students performed a similar experiment using two swan-necked flasks, one
containing broth which had been previously boiled and another containing broth
which had not been boiled.
The flasks were left in the school laboratory and observed after one week. What is
the evidence against the spontaneous generation theory?
A. Microorganisms died in flask F due to high temperatures.
B. No microorganisms grew in either flask.
C. Microorganisms grew in flask G.
D. No microorganisms grew in flask F but many grew in flask G.
4. How do both mitochondria and chloroplasts provide evidence for the [1 mark]
endosymbiotic theory?
A. They have double membranes.
B. They have 80S ribosomes similar to prokaryotes.
C. They contain the same DNA as the nucleus of the cell.
D. They exist together in eukaryote cells for their mutual benefit.
, Organisms have evolved a great diversity of cell types.
5a. Describe the endosymbiotic theory. [4 marks]
1. Which cell component arose first during the formation of the earliest [1 mark]
cells?
A. Chloroplast
B. Plasma membrane
C. Mitochondria
D. Cell wall
2. In the chimpanzee (Pan troglodytes), the haploid number of chromosomes[1 mark]
is 24. How many sister chromatids are present in the G2 phase of a
somatic cell, such as a cell in the bone marrow of the chimpanzee?
A. 12
B. 24
C. 48
D. 96
,3. Pasteur used swan-necked flasks and a nutrient broth to demonstrate [1 mark]
that spontaneous generation of organisms does not occur on Earth. Some
students performed a similar experiment using two swan-necked flasks, one
containing broth which had been previously boiled and another containing broth
which had not been boiled.
The flasks were left in the school laboratory and observed after one week. What is
the evidence against the spontaneous generation theory?
A. Microorganisms died in flask F due to high temperatures.
B. No microorganisms grew in either flask.
C. Microorganisms grew in flask G.
D. No microorganisms grew in flask F but many grew in flask G.
4. How do both mitochondria and chloroplasts provide evidence for the [1 mark]
endosymbiotic theory?
A. They have double membranes.
B. They have 80S ribosomes similar to prokaryotes.
C. They contain the same DNA as the nucleus of the cell.
D. They exist together in eukaryote cells for their mutual benefit.
, Organisms have evolved a great diversity of cell types.
5a. Describe the endosymbiotic theory. [4 marks]
