General

Question 1

Define genetic sex

Answer 1

Determined by presence/absence of a Y chromosome

Question 2

Primary sex characteristics

Answer 2

Development of the gonad
Sperm/egg development
Usually dependent on genotype (genetic sex)

Question 3

Secondary sex characteristics

Answer 3

Sex-specific structures of the urogenital system
External genitalia
Dependent on hormone signalling/signals from the environment

Question 4

What are pseudo-autosomal regions?

Answer 4

Regions on the X and Y chromosome responsible for pairing during meiosis

Question 5

Gene responsible for sex determination on Y chromosome

Answer 5

SRY gene

Question 6

How can have an XX male?

Answer 6

SRY gene is on the X chromosome

Question 7

How can have an XY female?

Answer 7

Absence of SRY gene on Y chromosome OR

Has a mutation which makes the person immune to testosterone.

Question 8

What does the SRY gene do?

Usually located on short arm of Y chromosome

Answer 8

Is responsible for sex determination

Encodes testis determining factor (TDF)

Question 9

TDF

Answer 9

Testis determining factor

From SRY gene

Question 10

Karyotype XO

Answer 10

Turner Syndrome
Phenotype: female
Fertility: no

Question 11

Karyotype: XXY

Answer 11

Kleinfelter Syndrome
Phenotype: male
Fertility: no

Question 12

Karyotype: XYY

Answer 12

XYY syndrome
Phenotype: male
Fertility: yes

Question 13

Karyotype: XXX

Answer 13

XXX syndrome
Phenotype: female
Fertility: reduced

Question 14

Karyotype: XXXY

Answer 14

Triple X Y syndrome
Phenotype: male
Fertility: no

Question 15

Karyotype: XXXX

Answer 15

Tetra X syndrome
Phenotype: female
Fertility: ?

Question 16

Karyotype: XXXXY

Answer 16

Tetra X Y syndrome
Phenotype: male
Fertility: no

Question 17

Main adhesion factors

Answer 17

Cadherins
Integrins
IgCAMs
Selectins

Question 18

Cadherins mediate…

Answer 18

Attachment cell-to-cell

Question 19

Integrins mediate…

Answer 19

Attachment cell-to-matrix

Question 20

During development, cadherins…

Answer 20

Mediate cell sorting

Question 21

Role of HSP90

Answer 21

Chaperone, refolding proteins
Works downstream to HSP70
Refolds kinases, receptors and cytoskeletal proteins; has role in cell cycle and chromosome maintenance

Question 22

Define phagocytosis

Answer 22

Cell consumes large molecules and whole cells

Question 23

Define pinocytosis

Answer 23

Cell consumes fluids and small molecules

Question 24

6 points at which proteins expression is controlled

Answer 24

1. Transcriptional control
2. RNA processing control
3. RNA transport and localising
4. Translational control
5. mRNA degradation control
6. Protein activity control

Question 25

What is the transcriptional control of protein expression?

Answer 25

Whether and how much a gene is transcribed affects the protein expression

Question 26

What is the RNA processing control of protein expression?

Answer 26

Different splicing and completing the mRNA affects protein expression

Question 27

How does control of RNA transport and localising (Step 3) affect protein expression?

Answer 27

The final location of the mRNA is part of determining the final outcome & hence the protein expression

Question 28

How does translational control affect protein expression?

Answer 28

Whether the mRNA is translated into protein affects protein expression

Question 29

Explain how mRNA degradation control affects protein expression

Answer 29

If the mRNA is degraded more before it is translated, there is less protein expressed. If it is degraded less, there is more protein expressed.

Question 30

Outline the mechanism by which phosphorylation (by CAK) allows the activation of cyclin-Cdk

Answer 30

Phosphorylation alters conformation of protein loop, allowing ATPase activity to drive kinase reaction.

Question 31

Alpha actin found in...

Answer 31

Muscle cells

Question 32

Beta and gamma actin found in...

Answer 32

Non-muscle cells

Question 33

The 4 types of cell adhesion molecule

Answer 33

Cadherins Integrins Selectins IgCAMs

Question 34

Common feature of IgCAMs

Answer 34

Ig-domain, a beta-sheet stabilised by di-sulfide bonding

Question 35

What are selectins?

Answer 35

Cell adhesion molecule in the bloodstream.

Question 36

3 types of selectin

Answer 36

E - epithelia L - leukocytes (most) P - platelets (secretory granules of)

Question 37

Weak adhesion and rolling mediated by...

Answer 37

Selectins

Question 38

What are integrins?

Answer 38

Cell adhesion molecules | Responsible for cell-matrix adhesion

Question 39

What are cadherins?

Answer 39

Cell adhesion molecules | Responsible for cell-cell adhesion

Question 40

What is the most common cell adhesion molecule in vertebrates?

Answer 40

N-CAM

Question 41

Which type of cell junctions are actin filaments anchored to?

Answer 41

``` Adherens junctions (cell-cell) Actin-linked cell-matrix adhesions ```

Question 42

What type of cell junctions are intermediate filaments anchored to?

Answer 42

Desmosomes (cell-cell) | Hemidesmosomes (cell-matrix)

Question 43

What are the cadherins in desmosomes?

Answer 43

Desmocollin | Desmoglein

Question 44

What are the intracellular anchoring proteins associated with desmosomes?

Answer 44

Plakophilin Plakoglobin Desmoplakin

Question 45

Homophilic binding

Answer 45

CAMs only bind to their own kind (cadherins to cadherins, etc.)

Question 46

Heterophilic binding

Answer 46

CAMs binding to molecules outside their class

Question 47

The plant equivalent of a gap junction

Answer 47

Plasmodesmata

Question 48

What are the classical cadherins?

Answer 48

N - CNS E - embryonic, epithelia P - placenta and epidermis VE - endothelia

Question 49

Why are cadherins Ca++ dependent?

Answer 49

Ca++ binds between the subunits, making them rigid by preventing them from flexing. Without Ca++, the molecule is limp and can't bind.

Question 50

What are the intracellular anchoring proteins associated with cadherin junctions?

Answer 50

alpha, beta and gamma catenins