BIOLOGY AS LEVEL OCR QUESTIONS WITH
VALIDATED ANSWERS.
It states that the cell is the fundamental structure of all living matter, and
that cells can only develop from other existing cells. - CORRECT ANSWER -
What is cell theory? (2 points)
When the product of a reaction acts as an inhibitor for the enzyme that
produces it. - CORRECT ANSWER -What is end-product inhibition?
Mitosis is the division of the nucleus. Cytokinesis is the division of the
cytoplasm where the two cells are produced. - CORRECT ANSWER -What is the
difference between mitosis and cytokinesis?
The period where cells are not actively dividing. It is in this phase that the
cell is replicating DNA and checking for errors, where mitochondria grow
and divide, and where some of the metabolic processes occur. - CORRECT
ANSWER -What is interphase?
G1 - the first growth phase where the cell increases in size as organelles are
made.
S - Synthesis phase, where DNA is replicated in the nucleus.
G2 - the second growth phase where the cell continues to increase in size as
the energy stores increase and the duplicated DNA is checked. - CORRECT
ANSWER -Main stages of interphase?
This is the phase where the cell leaves the cycle, either temporarily or
permanently. - CORRECT ANSWER -What is G0?
,It differentiates - specialised cells are no longer able to divide.
The DNA becomes damaged - if DNA becomes damaged, the cell enters a
stage of permanent cell arrest. - CORRECT ANSWER -A cell will enter G0
permanently if...
It is a lymphocyte, as these leave the cell cycle and can be stimulated to
reenter in an immune response. - CORRECT ANSWER -A cell will enter G0
temporarily if...
Checkpoints - CORRECT ANSWER -What is the name given to the positions in
the cell cycle at which different checks are made before a cell enters another
stage?
- Chromatin fibres coil and condense to form chromosomes.
- The nuclear envelope disintegrates.
- Spindle fibres form at either pole of the cell. - CORRECT ANSWER -What
happens during Prophase in mitosis?
- Chromosomes are moved by spindle fibres to form a plane along the
equator of the cell. This is known as the metaphase plate. - CORRECT ANSWER
-What happens during Metaphase in mitosis?
- Centromeres divide, separating the chromatids as the spindle fibres
shorten. - CORRECT ANSWER -What happens during Anaphase in mitosis?
- The chromatids have reached the poles and the nuclear envelope reforms
around the two new sets of chromosomes. - CORRECT ANSWER -What happens
during Telophase in mitosis?
,- A cleavage furrow forms around the middle of the cell and the
cytoskeleton pulls the membrane inwards.
- In plants, a cleavage furrow cannot form as they have a cell wall. Instead,
vesicles align on the metaphase plate, and fuse to the cell surface
membrane, dividing the cell into two. - CORRECT ANSWER -What happens
during Cytokinesis?
Two genetically identical, diploid daughter cells. - CORRECT ANSWER -Mitosis
produces...
Four genetically different haploid daughter cells. - CORRECT ANSWER -Meiosis
produces...
The first one. - CORRECT ANSWER -Which division in mitosis is classed as the
reduction division?
- The chromosomes condense.
- The nuclear envelope disintegrates.
- Spindle formation begins.
- The homologous chromosomes pair up, forming bivalents. - CORRECT
ANSWER -What happens during Prophase 1 in Meiosis 1?
- Homologous pairs of chromosomes pair up along the metaphase plate
All living organisms are composed of cells, and since most cells are too
small to see without a microscope, we cannot observe the functions of cells
and their organelles without one. - CORRECT ANSWER -Outline the importance
of microscopes in the study of living organisms.
, Before then, microscope magnification was not as powerful, and so
scientists were unable to see and identify single cells or cell components. -
CORRECT ANSWER -Why was cell theory not fully developed before the mid-
19th century?
1. Place the stage micrometer on the stage and align it with the eyepiece
graticule.
2. Remember that each division on the stage micrometer is 10 micrometres.
3. Each eyepiece division is calculated by dividing the number of eyepiece
divisions by the number of micrometres.
4. Replace the stage micrometer with a specimen to measure. - CORRECT
ANSWER -Describe the process of calibrating a microscope.
How many times larger the image is than the actual size of the object. -
CORRECT ANSWER -Define magnification.
It has two lenses - the objective lens near the specimen, and the eyepiece
lens, through which the specimen is viewed. - CORRECT ANSWER -How does a
compound light microscope work?
A mount used to observe solid specimens, where the specimen is sectioned
and a cover slip is placed over the top. - CORRECT ANSWER -What is a dry
mount?
A mount used to observe specimens suspended in water or immersion oil. -
CORRECT ANSWER -What is a wet mount?
VALIDATED ANSWERS.
It states that the cell is the fundamental structure of all living matter, and
that cells can only develop from other existing cells. - CORRECT ANSWER -
What is cell theory? (2 points)
When the product of a reaction acts as an inhibitor for the enzyme that
produces it. - CORRECT ANSWER -What is end-product inhibition?
Mitosis is the division of the nucleus. Cytokinesis is the division of the
cytoplasm where the two cells are produced. - CORRECT ANSWER -What is the
difference between mitosis and cytokinesis?
The period where cells are not actively dividing. It is in this phase that the
cell is replicating DNA and checking for errors, where mitochondria grow
and divide, and where some of the metabolic processes occur. - CORRECT
ANSWER -What is interphase?
G1 - the first growth phase where the cell increases in size as organelles are
made.
S - Synthesis phase, where DNA is replicated in the nucleus.
G2 - the second growth phase where the cell continues to increase in size as
the energy stores increase and the duplicated DNA is checked. - CORRECT
ANSWER -Main stages of interphase?
This is the phase where the cell leaves the cycle, either temporarily or
permanently. - CORRECT ANSWER -What is G0?
,It differentiates - specialised cells are no longer able to divide.
The DNA becomes damaged - if DNA becomes damaged, the cell enters a
stage of permanent cell arrest. - CORRECT ANSWER -A cell will enter G0
permanently if...
It is a lymphocyte, as these leave the cell cycle and can be stimulated to
reenter in an immune response. - CORRECT ANSWER -A cell will enter G0
temporarily if...
Checkpoints - CORRECT ANSWER -What is the name given to the positions in
the cell cycle at which different checks are made before a cell enters another
stage?
- Chromatin fibres coil and condense to form chromosomes.
- The nuclear envelope disintegrates.
- Spindle fibres form at either pole of the cell. - CORRECT ANSWER -What
happens during Prophase in mitosis?
- Chromosomes are moved by spindle fibres to form a plane along the
equator of the cell. This is known as the metaphase plate. - CORRECT ANSWER
-What happens during Metaphase in mitosis?
- Centromeres divide, separating the chromatids as the spindle fibres
shorten. - CORRECT ANSWER -What happens during Anaphase in mitosis?
- The chromatids have reached the poles and the nuclear envelope reforms
around the two new sets of chromosomes. - CORRECT ANSWER -What happens
during Telophase in mitosis?
,- A cleavage furrow forms around the middle of the cell and the
cytoskeleton pulls the membrane inwards.
- In plants, a cleavage furrow cannot form as they have a cell wall. Instead,
vesicles align on the metaphase plate, and fuse to the cell surface
membrane, dividing the cell into two. - CORRECT ANSWER -What happens
during Cytokinesis?
Two genetically identical, diploid daughter cells. - CORRECT ANSWER -Mitosis
produces...
Four genetically different haploid daughter cells. - CORRECT ANSWER -Meiosis
produces...
The first one. - CORRECT ANSWER -Which division in mitosis is classed as the
reduction division?
- The chromosomes condense.
- The nuclear envelope disintegrates.
- Spindle formation begins.
- The homologous chromosomes pair up, forming bivalents. - CORRECT
ANSWER -What happens during Prophase 1 in Meiosis 1?
- Homologous pairs of chromosomes pair up along the metaphase plate
All living organisms are composed of cells, and since most cells are too
small to see without a microscope, we cannot observe the functions of cells
and their organelles without one. - CORRECT ANSWER -Outline the importance
of microscopes in the study of living organisms.
, Before then, microscope magnification was not as powerful, and so
scientists were unable to see and identify single cells or cell components. -
CORRECT ANSWER -Why was cell theory not fully developed before the mid-
19th century?
1. Place the stage micrometer on the stage and align it with the eyepiece
graticule.
2. Remember that each division on the stage micrometer is 10 micrometres.
3. Each eyepiece division is calculated by dividing the number of eyepiece
divisions by the number of micrometres.
4. Replace the stage micrometer with a specimen to measure. - CORRECT
ANSWER -Describe the process of calibrating a microscope.
How many times larger the image is than the actual size of the object. -
CORRECT ANSWER -Define magnification.
It has two lenses - the objective lens near the specimen, and the eyepiece
lens, through which the specimen is viewed. - CORRECT ANSWER -How does a
compound light microscope work?
A mount used to observe solid specimens, where the specimen is sectioned
and a cover slip is placed over the top. - CORRECT ANSWER -What is a dry
mount?
A mount used to observe specimens suspended in water or immersion oil. -
CORRECT ANSWER -What is a wet mount?
