Crowdly

Image failed to load: cell cycle1

This image illustrates stages of the cell cycle.

Which statement is CORRECT?

M phase is completed in about 1 – 2 days

The cycle typically lasts for 24 days

Checkpoints occur only in M or G1 phase

Metaphase occurs during S phase

G0 is a resting phase and occurs during G1

Image failed to load: cell cycle2

Choose the CORRECT statement.

In G1 phase of the cell cycle:

Production of proteins that inhibit entry into S-phase increases

The cell doubles in size due to the presence of extra proteins and organelles

Chromosome condensation occurs

Cells spend the shortest period of time

Normal cell function halts

Checkpoints in the Cell Cycle rely upon the actions of:

Cyclin proteins and enzymes called kinases

Synthesis of DNA with duplication of chromosomes

Cyclic fluctuations of estrogens and androgens

Cyclic rise and fall of cytokinesis

Assembly or disassembly of microtubules

Which of the following statements are true:

Uterine muscle contractions are critical in getting the sperm into the oviduct

Fertilisation occurs primarily in the cervical epithelium of the female reproductive tract

Sperm capacitation holds sperm up in the cumulus matrix preventing them from reaching the egg

All of the above are correct

Sperm become hyperactive prior to their release into the vagina

Which statement is not related to the acrosome reaction:

Digestion of the egg’s zona pellucida occurs via proteases released from the acrosome

Sperm undergo the acrosome reaction only after having resided in the female reproductive tract for some time

Capacitation of sperm and penetration through the cumulus of the egg occurs only after the acrosome reaction

Fusion occurs between the acrosomal vesicle and the sperm membrane

Exocytosis results in the release of various proteolytic enzymes

Which of the following statements relating to gastrulation is CORRECT?

Choose the CORRECT option below:

Cells that migrate through the primitive streak to displace the hypoblast become ectoderm

Cells that move through the primitive streak to the mid-layer form mesoderm

Cells that undergo gastrulation form the germ cell lineage

Cells that remain in the epiblast layer become endoderm

Which are the two key factors secreted by the node to set up left-right asymmetry in development?

Choose the CORRECT option below:

SRY and Ey

BMP4 and Shh

Nodal and lefty

Shh and FGF8

At which phase of the cell cycle can you perform a karyotype analysis?

Choose the CORRECT option below:

Prophase

Telophase

Metaphase

Anaphase

At which stage of sperm maturation does capacitation take place?

Following exposure to enzymes secreted by the uterine wall

During transit through the epididymis

During spermatogenesi

During colonisation of the gonad

Following exposure to the seminal fluid produced by the prostate