- (d) : Fishes consume oxygen irrespective of whether they
are at resting or in active state. The solubility of oxygen in
water decreases with the rise in temperature, so oxygen
consumption rate will also increase in both resting as well
as active fishes as depicted in graph (d). - (c) : From the given experiment, it can be concluded
that both the interacting species are being benefitted
(mutualism). This is because while the crabs help in the
survival of the corals by preventing the outgrowth of
seaweeds (algae), the corals support the survival of the
crabs by protecting them from predation. Oculina arbuscula
can survive in the absence of Mithrax forceps (as shown in
coral growth graph). So presence of Mithrax forceps is not
obligatory for survival of coral Oculina arbuscula. - (c) : Crustaceans belong to the Phylum Arthropoda in which
sexes are separate (dioecious) and sexual dimorphism is
observed in them. In oligochaetes and flatworms, sexes are
separate, while gastropods are hermaphrodites, some have
separate sexes. - (b) : The number of gametes formed by an individual can
be calculated by applying the formula of 2n where n is the
number of heterozygous gametes present in an individual. In
the given question, the individual in option (b) will produce
16 gametes as the number of heterozygous gametes present
is 4. Therefore, by applying the formula of 2n, we can
conclude that 2^4 = 6, i.e., 16 gametes will be produced. - (c) : Tapeworm belongs to Phylum Platyhelminthes that
lack metameric segmentation while nereid worm belongs
to Phylum Annelida and centipede belonging to Phylum
Arthropoda are characterised by metameric segmentation. - (d) : F-type ATPases are one of the transmembrane ATPases
found in mitochondria, chloroplast and bacterial plasma
membranes where they are prime producers of ATP. In
plasma membrane of fungi, P-type ATPases are found. - (d) : In ectomycorrhiza, the fungal hyphae lies in
intercellular spaces of the cortex and does not penetrate
the cortical cells. The root cells secrete sugars and other
food ingredients into the intercellular spaces for feeding the
fungal hyphae. - (b) : Bog is a wet, muddy and spongy ground that is
rich in dead and decaying plant material. Hence, it is a
perfect habitat for microbes due to high moisture content,
anaerobic conditions and organic matter. - (c)
- The figures depict representative illustrations of three
categories of animals with segmented bodies.
A : Tapeworm B : Nereid worm C : CentipedeWhich of these animal/s show metameric segmentation?
(a) B only (b) A and B
(c) B and C (d) A and C (INBO 2015)
- There are various types of ATPase pumps found in different
types of cells. Of these, F-type ATPases, also known as ATP
synthases, drive ATP synthesis. They are found in all of the
following except
(a) inner membrane of mitochondria
(b) thylakoid membrane of chloroplasts
(c) plasma membrane of prokaryotes
(d) plasma membrane of fungi. (INBO 2014) - Ectomycorrhiza – a symbiotic association between plant
roots and fungi is important in obtaining phosphorus and
other nutrients for the plant. Which of the following points
characterise the relationship?- Penetration of host cell by fungal hyphae
- Creation of a vast network of hyphae to absorb nutrients
- Change in soil pH
- Movement of organic carbon to fungi
(a) 1, 2, 3 and 4 (b) Only 1, 2 and 3
(c) Only 2 and 3 (d) Only 2, 3 and 4(INBO 2014)
- Denitrification is a process carried out by microbes in which
nitrates are reduced to molecular nitrogen. This process is
predominant in
(a) desert (b) bog
(c) leached soil (d) tilled farm. (NSEB 2013-14) - Arrange the following processes sequentially to explain the
translocation of food through sieve tubes.
i. Unloading of sugar in sink cells (or cells of root)
ii. Uptake of water from xylem vessels
iii. Transfer of water from sieve cells to xylem vessels
iv. Sugars loaded from leaf cells to sieve cells
(a) ii → iv → iii → i (b) iv → iii → ii → i
(c) iv → ii → i → iii (d) i → iii → iv → ii
(INBO 2013)
SOLUTIONS- (b) : Stabilising selection eliminates extremes from the
population, reducing variations and hence rates of evolution
are typically slow. The plants growing on high-zinc-soil are
able to grow due to directional selection as it is a change
towards one particular direction, i.e., favours only one plant
species and eliminates rest of them.