B.

While lipids and proteins can flip -flop

singer and Nicolson (1972) suggested the widely accepted fluid mosaic model of biological membranes. According to this model, the plasma membrane contains a bimolecular lipid layer, both surface of which are interrupted by protein molecules. Some proteins are attached to the polar surface of the lipid (ie, called extrinsic protein) while, other (called intrinsic proteins) either partially entirely to stick but on both sides (called transmembrane proteins). The Movement of lipid molecules from one lipid monolayer to another monolayer is called flip-flop movement. Flip-flop movement is rarely found in lipid molecules whereas it remain absent in protein molecules.

D.

they have more chloroplasts

Chloroplasts in bundle sheath cells are larger and always contain grana whereas chloroplasts in mesophyll cells are smaller. The C₄ - plants are photosynthetically more efficient than c₃ -plants because they more chloroplasts.

D.

Total lung capacity minus residual volume

Vital capacity is the sum of inspiratory reserve volume, tidal volume and expiratory reserve volume. It is about 4800 mL.
Total lung capacity is the sum of vital capacity and residual volume, ie, vital capacity minus residual volume.
Tidal volume is the amount of air, which normally passes into and out of the lungs during each cycle of quite breathing. It is about 800 mL in an adult person.
Inspiratory reserve volume is the extra volume of air that can be inhaled into lungs during deepest possible inspiration.

A.

Pteris

In Pteris (also Dryopteris) the spore germinates to produce the prothallus. The prothallus is small, green, flat, surface loving, thallus - like object. It is monoecious and bears sex organs on the ventral side. The antheridia (male sex organs) arise among the rhizoids towards the posterior side of the prothallus and are emergent. The archegonia develop in central cushion behind the apical notch. In these plants, male and female gametophytes do not have free living independent existence. 
All species of polytrichum are dioecious. The antheridia and archegonia are borne on different gametophore. The plant body is an erect leafy shoot but is not the entire gametophyte. The leafy shoot arises from protonema (the juvenile stage).
The leafy gametophore of Funaria reproduces sexually by the formation of antheridia and archegonia. The antheridia are formed at the summit of relatively small, thin leafy shoot which develops first. The female branch arises later as a lateral outgrowth from the base of parent male shoot. 

B.

leaf abscission

Senescence can be defined as ' the sum of deteriorative processes, which naturally terminate the functional life of an organism'. Senescence is not confined only to the whole plant, it may be limited to a particular plant organ such as leaf and flower or cells such as phloem and xylem. Abscission is the natural shedding of leaves, foliage branches, fruits, floral parts etc. According to Leopold (1967) abscission is a Senescence phenomenon. Senescence as an active development cellular process in growth and functioning of a flowering plant is indicted in leaf abscission.
Whole plant senescence also known as overall senescence occur in annulas (eg, rice, wheat, gramme, mustard) biennials (eg, henbane or perennials.)