Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Alevel Biology year 1 > Cell division, Cell diversity and Cellular organisation > Flashcards

Cell division, Cell diversity and Cellular organisation Flashcards

(61 cards)

Start Studying
1
Q

3 phases of cell cycle

A

interphase, mitotic phase, G0 phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

interphase

A

time of growth and preparation for cellular division
DNA replicated and checked for errors
protein synthesis in cytoplasm
chloroplast and mitochondria grow in number

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

stages of interphase

A

g1- growth phase(organelles produced and replicate
S- DNA replication
g2- second growth phase continued growth in size and DNA checked for error

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

miotic phase

A

mitosis- nucleus divides
cytokinesis - cytoplasm divides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

G0

A

cell leaves cycle temporarily or permamently
differentiation- cell specialised to carry out a function can no longer divide
DNA might be damaged so it enters arrrest apoptosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

how do chromosomes act in mitosis

A

DNA molecules converted into two identical DNA molecules called chromatid joined together by the centromere
important to be kept together to be precisely manoeuvred/ segregated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is the importance of mitosis

A

ensures both daughter cells are genetically identical to the parent cells, they will have the exact copy of DNA in present cells and the same number of chromosomes
growth, repair, asexual reproduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

how is the cell cycle controlled

A

checkpoints are done to ensure the cell is process of each phase has been accurately completed
G1check point- end of g1 phase makes sure cell has met requirements
G2check point- at the end of the G2 phase(checks DNA has been replicated properly and cell begins mitosis
spindle checkpoint- makes sure all of the chromosomes are correctly attached to the spindles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what are the stages of mitosis

A

prophase, metaphase, anaphase and telophase
they are all interlinked and work between themselves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Prophase

A

chromatin condenses and becomes visible and nuclear membrane breaks down
microtubules form spindle shaped structures linking poles of the cell
centrioles migrate to the poles of cell to help the formation of the spindle fibres
the spindle fibres attach to parts of the chromosomes and move to metaphase plate
at the end nuclear envelope has disappeared

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

metaphase

A

chromosomes moved by the spindle fibres to the metaphase plate and lined upheld in position

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Anaphase

A

The spindle fibres attach to the centromeres of the chromosome on both sides and splits it in two, fibres contract and pull the chromatids to each side of the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

telophase

A

Once the chromatids reach the poles they are called chromosomes, new sets of chromosomes assemble at the poles and the nuclear envelope forms around them, chromosomes uncoil and nucleolus forms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

cytokinesis

A

actual splitting of the membrane into two different cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

animal cytokinesis

A

cleavage furrow forms around middle of the cell membrane pulled inwards until it can fuse with itself and pinch of into two

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

plant cell cytokinesis

A

cell wall stops cleavage furrow, so vesicles from the Golgi apparatus assemble at the metaphase plant all using together until the cell is split into two and new cell walls form around the membranes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what type of chromosomes are made in mitosis

A

diploid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what type of chromosomes are made in meosis

A

haploid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what are homolgus chromosomes

A

chromosomes from each parent that have the same matching genes(pair) for each characteristic)
same genes in the same posititns

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Allele?

A

different versions of the same gene eg the gene for eye colour varies blue/ brown eyes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what are the stages of meiosis

A

meiosis 1- reduction division when the pairs of chromosomes are separated in two cells
meiosis 2- second division pair of chromosomes are separated forming 2 more cells 4 haploid daughter cells in total

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Meiosis 1(p1)

A

-chromosomes condense nuclear envelope/ nucleolus disappears
-spindle fibres begin to form
-homologous chromosomes pair up (bivalents)
-chromosomes are large molecules and as they move around in cytoplasm they get entangled and DNA crosses over

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Meiosis1(m1)

A

homologous pairs of chromosomes assemble on the metaphase plate
assembly of the homologous chromosomes on the metaphase plate is random maternal/ paternal chromosomes can end up facing either pole(independent assortment)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Meiosis1(anaphase 1)

A

homologous chromosomes pulled apart but the chromatid stay together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
crossing over
When entangled chromatids are pulled apart they break off and exchange DNA points at which they break/join (chiasmata) when re-joined they form recombinant chromosomes genes shared (different alleles for genetic variation
18
meiosis1(T1)
same as mitosis chromosomes assemble they uncoil membrane reforms and cytokinesis divides the two cells haploid cells
19
meiosis2(p2)
chromosomes consist of 2 chromatid condense and become visible nuclear envelope breaks down spindle fibres form
20
meiosis2(m2)
individual chromosomes line up at metaphase plate chromatids aren't identical so there is independent assortment and more genetic variation
21
meiosis2(a2)
chromatids of individual chromosomes pulled to opposite poles after centromere division
22
meiosis2(t2)
assemble at the poles uncoil into chromatin nuclear envelope and nucleolus appear cytokinesis causes the cells to be 4 daughter haploid cells which are genetically varied
23
levels of organism?
specialised cells- tissues-organs-organ systems- whole organism
24
Specialised cells
differentiated, meaning they are specialised for their function
25
erythrocytes specialisations
flattened biconcave for large SA:VOL ratio for o2 transport have no nucleus more space for haemoglobin flexible to squeeze through capillaries
26
neutrophils(wbc) specialisations
multi loved nucleus to squeeze though small gaps for infections granular cytoplasm with many lysosomes that contain enzymes to attack pathogens
27
Sperm cells specialisations
deliver genetic information tail/flagellum to move plentiful mitochondria to supply the energy needed to swim acrosome that contain digestive enzymes to penetrate the egg
28
Palisade cells
Large amounts of chloroplasts for light absorption. Thin cell walls which increases rate of diffusion for Co2 ,choloroplast can move in the cytoplasm
29
root hair cells
Large surface rea for maximum water uptake from the soil
30
Guard cells
form opening of stomata, change shape to prevent water loss. cell wall thicker on one side shape symmetrically as the volume changes
31
categories of tissues
nervous tissue; adapted to support transmission of electrical impulses epithelial tissue; adapted to cover body surfaces (internal/external) muscle tissue; adapted to contract connective tissue; to hold other tissues together or a transport medium
32
squamous epithelium
flat cells and thin(one cell thick) for fast diffusion of gaseous material in lung lining for rapid diffusion of o2 into the blood
33
ciliated epithelium
line with cilia that beat to move mucus/ trapped particles out of trachea they have goblet cells that secrete mucus to trap any pathogens
34
cartilage
connective tissue contains fibres of elastin and collagen. firm tissue that prevents ends of bones from rubbing together
35
muscle
can shorten and contract which moves the body skeletal muscles fibres( attached to bone) contains myofibrils and contractile proteins
36
epidermis
closely pack cells on plant surface which is covered by a waxy cuticle to reduce water loss stomata are present in the epidermis
37
xylem tissue
transport of water/ minerals throughout plants composed of vessel elements which are elongated dead cells strengthened by lining water proof and provides strength
38
phloem tissue
transports of assimilates(sucrose mainly) from leaves to where it is needed, column of sieve tube elements separated by sieve plates
39
organ systems
digestive system, cardiovascular system, gaseous exchange system
40
what is a stem cell
an undifferentiated cell that can differentiate into any cell, can keep dividing and be a source for cells necessary for growth, development and repair. Once specialised they can no longer divide too slow division leads to aging to fast division leads to cancer
41
what is stem cell potency
ability for a cell to differentiate (potency)
42
totipotent-
can differentiate into any type of cell, fertilised egg, zygote are totipotent cells meaning they can produce a whole organism
43
pluripotent
can form all tissue but not whole organisms, mainly in early embryos origin of different tissues in a cell
44
multipotent
wide range of cells within a certain tissue(haemopoietic can give rise to different types of blood types in the bone marrow )
45
differentiation
when cells change shape for certain functions or a specific roles all RBC come from stem cells in the bone marrow
46
replacement of red and white blood cells
they lack organelles and have a short life span(120) need to be replaced constantly stem cell colonies produce 3 billion erythrocytes per kg of body mass every day neutrophils live about 6 hours so stem cell colonies in bone marrow produce about 1.6 billion per kg per hour of WBC which increases during infection
47
what are the sources of stem cells
embryonic stem cells- early stage of development they are totipotent, after 7 days they become blastocyst and the cells are now pluripotent adult stem cells- throughout a persons life time, found in bone marrow they are multipotent but can be triggered to become pluripotent
48
whys are embryonic cells preferred
plenty umbilical cords to use and there is no need for an invade process to remove the stem cells
49
what is the source of stems cells in plants
meristematic tissue which is found where growth occurs in plants(root/shoot) also found between the phloem and xylem (vascular cambium) which differentiate into xylem or phloem cells
50
Use of stem cells
51
heart disease
muscle tissue damaged from heat attack
52
embryo creation
embryos created intentionally to take the cells away from them and kill the cells controversy as to if the cell has rights or not
53

Alevel Biology year 1 (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions