Cytokinesis in animal cells involves: a) alignment of the spindle along the equatorial plane. b) formation of a cleavage furrow. c) pinching in the original cell wall to produce a new cell wall between daughter cells. d) contraction of a ring of actin microfilaments. e) development of a cell plate that grows out until it reaches the plasma membrane.

The correct answer will be options-B and D

Explanation:

Cytokinesis is the process of cell division which divides the cellular components along with the nuclear component. The cytokinesis takes place after the completion of M-phase which differs in both animal and plant cell.

In an animal cell, the cytokinesis begins by the formation of furrow which eventually pinches off to two cells.

The formation of the furrow is a complex process and requires the microtubules like an actin-myosin ring which gets established in which the actin filaments from the ring. The myosin filaments pull the actin filaments and then forms the ring.

Thus, options-B and D are the correct answer.

relative dating involves things like higher layers are most recent than rocks lower in the sequence. this can be extended to the known sequence of fossils. rocks containing rabbit fossils are later than those containing dinosaur fossils.  

absolute dating methods mainly use radioactive elements that have known rates of decay and produce recognizable products. for example potassium 40 decays to produce argon. once a rock has solidified the argon is trapped. by measuring the argon and potassium0 you can get an accurate number for the age.  

some other methods are good for archaeological ages. dendrochronology involves recognizing the sequence of tree rings. the orientation of magnetized particles in baked clay can be used to date a fire.

hope this .. .