B2 Flashcards
1
Q
- what is the role of the nucleolus
A
manufactures ribosomal RNA (rRNA)
2
Q
- what organelle is found in plant and algae cells but not animal cells
A
- cell wall
- vacuole
- chloroplasts
3
Q
- what organelle is used by phagocytes to digest pathogens
A
lysosomes
4
Q
- what organelle carries out protein synthesis
A
ribosomes
5
Q
- what does the RER do
A
synthesises proteins
6
Q
- what does the SER do
A
synthesises lipids
7
Q
- what does the golgi body do
A
- modifies proteins and lipids
- forms vesicles (to transport modified proteins to cell membrane)
- forms lysosomes
8
Q
- what is the function of a cell wall in plants
A
provides mechanical strength
prevents lysis when water enters
9
Q
- what CANT be seen in an OPTICAL microscope but CAN be seen in an electron microscope
A
ribosomes
10
Q
- what CAN be observed using an optical microscope that CANT be observed using an electron microscope
A
living specimen
specimen in colour
11
Q
- why does an electron microscope have better resolution than an optical microscope
A
electrons have shorter wavelength than light
12
Q
- what are the 3 stages of the cell cycle
A
interphase
nuclear division (mitosis/meiosis)
cytokineses
13
Q
- what stage of the cell cycle does DNA replication happen in?
A
interphase
14
Q
- what is replicated in interphase
A
DNA
organelles
15
Q
- what are homologous chromosomes
A
not identical but have the same gene loci
16
Q
- what can differ on the homologous chromosomes
A
the alleles
17
Q
- where do the homologous chromosomes come from
A
paternal
maternal
18
Q
- what do you call a cell that has homologous chromosomes arranged in pairs
A
diploid
19
Q
- what do you call a cell that contains one of each homologous pair
A
haploid
20
Q
- what are the components of chromatin
A
DNA and histone
21
Q
- what are sister chromatids
A
genetic copies of a chromosome
attached by a centromere
22
Q
- name the stages of mitosis
A
prophase
metaphase
anaphase
telophase
23
Q
- how can you tell if a cell is undergoing mitosis when observing under a microscope
A
chromosomes are condensed and therefore visible
double the amount of DNA
24
Q
- during which phase do chromosomes line up along the equator of the cell
A
metaphase
25
81. during what stage are sister chromatids separated
anaphase
26
82. what part of the cell is needed for anaphase to happen
mitochondria - to provide energy
27
83. describe what happens in prophase
chromosomes condense and become visible
nuclear envelope disintegrates
nucleolus disappears
28
84. describe cytokineses
cytoplasm and cell membrane divides
forming 2 genetically identical cells
29
85. describe the behaviour of chromosomes during mitosis and explain how this results in the production of two genetically identical cells
1. chromosomes shorten/thicken/supercoiling
2. chromosomes (each) two identical chromatids (due to replication)
3. chromatids move to equator
4. attach to individual spindle fibres
5. spindle fibres contract/centromeres divide
30