Population Interactions Questions in English

(C) Brood parasitism is a phenomenon in which a parasitic bird lays its eggs in the nest of a host bird and lets the host incubate them. This is a classic example of parasitism observed in birds $(Aves)$. $A$ well-known example is the cuckoo ($Cuculus$ $canorus$) laying its eggs in the nest of a crow.

(D) Parasitism is a type of population interaction where one organism,known as the parasite,derives nutrition and shelter from another organism,known as the host. In this interaction,the parasite is benefited $(+)$ while the host is harmed $(-)$. Therefore,it is a $(+, -)$ interaction.

(B) . Calotropis is a plant that produces highly poisonous cardiac glycosides,which protect it from herbivores. Thus,$A-iv$.
$B$. Pisaster is a starfish that acts as a predator in rocky intertidal communities of the American Pacific Coast,feeding on invertebrates. Thus,$B-i$.
$C$. The Monarch butterfly is highly distasteful to its predator (birds) because of a special chemical acquired during its caterpillar stage. Thus,$C-ii$.
$D$. Frogs are often cryptically coloured (camouflaged) to escape detection by predators. Thus,$D-iii$.
Therefore,the correct matching is $A-iv, B-i, C-ii, D-iii$.

(C) The correct statement is $III$.
Explanation of incorrect statements:
$I$. $Cuscuta$ is a parasitic plant that lacks chlorophyll and cannot perform photosynthesis; it is not a chlorophyllous endoparasite.
$II$. The human liverfluke ($Fasciola$ $hepatica$) requires two intermediate hosts (a snail and a fish) to complete its life cycle.
$IV$. In brood parasitism,the parasitic bird's eggs have evolved to resemble the host's eggs in size and color to avoid detection by the host,not the other way around.
$III$. Endoparasites exhibit extreme specialization,which makes their life cycles more complex as they must adapt to the host's internal environment and often require multiple hosts.

(C) The correct option is $C$.
Population interactions are defined by the effect on the two interacting species:
$1$. $+,+$ (Mutualism): Both interacting species benefit.
$2$. $-,-$ (Competition): Both interacting species are harmed.
$3$. $+,o$ (Commensalism): One species benefits,while the other is neither benefited nor harmed.
In contrast:
- Parasitism $(+,-)$ and Predation $(+,-)$ involve one species benefiting at the expense of the other.
- Amensalism $(-,o)$ involves one species being harmed while the other remains unaffected.

(B) The correct answer is $B$.
$Statement-I$ is true: The Monarch butterfly feeds on poisonous weeds during its caterpillar stage, which allows it to acquire toxic chemicals.
$Statement-II$ is true: These chemicals make the butterfly highly distasteful to its predators (birds).
Since the accumulation of toxins from the weeds is the direct reason why the butterfly becomes distasteful, $Statement-II$ is the correct explanation of $Statement-I$.

$(C)$ brood parasitism.
In brood parasitism, the parasitic bird lays its eggs in the nest of its host, and the host incubates them.
During the course of evolution, the eggs of the parasitic bird have evolved to resemble the host's eggs in size and color to reduce the chances of the host bird detecting the foreign eggs and ejecting them from the nest.

(B) The correct answer is $B$.
Mac Arthur observed that $5$ closely related species of warblers living on the same tree were able to avoid competition and co-exist due to behavioral differences in their foraging activities.
This phenomenon is known as resource partitioning,where species sharing the same habitat divide resources to minimize competition and allow for coexistence.

(D) $Mutualism$ is a biological interaction where both interacting species benefit from the relationship.
In $Lichens$,algae and fungi live in a mutually beneficial association.
In $Mycorrhiza$,fungi and roots of higher plants show a mutualistic relationship.
Pollination involves a mutualistic interaction between plants and animals,where plants get pollinated and animals get food (nectar/pollen).
However,the association between cattle egrets and grazing cattle is an example of $Commensalism$,not $Mutualism$. In this interaction,the egret benefits by finding insects disturbed by the cattle,while the cattle are neither benefited nor harmed.

(D) Competition.
In competitive interactions,members of the species strive to obtain the same limited resources,that is,they compete for resources.
In this type of interaction,both the interacting organisms do not necessarily need to live in close proximity to each other,as they may be competing for resources that are available in the same environment or habitat.

(B) . Competition.
It was observed that in the deeper zones,$Balanus$ barnacles could always outcompete $Chthamalus$ barnacles.
$Balanus$ barnacles used the resources of the deeper zone more efficiently than $Chthamalus$ organisms,even though $Chthamalus$ barnacles are able to survive there in the absence of their competitor.

(C) Population interactions are classified based on the effect on the two interacting species ($A$ and $B$):
$(1)$ Mutualism $(+, +)$
$(2)$ Competition $(-, -)$
$(3)$ Predation $(+, -)$
$(4)$ Parasitism $(+, -)$
$(5)$ Commensalism $(+, 0)$
$(6)$ Amensalism $(-, 0)$
In amensalism,one species is harmed (negatively affected) while the other remains unaffected $(0)$.

(D) Joseph Connell performed elegant field experiments on the rocky sea coasts of Scotland.
He demonstrated that the larger and competitively superior barnacle,$Balanus$,dominates the intertidal area and excludes the smaller barnacle,$Chthamalus$,from that zone.

(C) The correct statements are $B, D$,and $E$.
- $B$: Mutualism $(+,+)$: Both species benefit.
- $D$: Parasitism $(+,-)$: One species benefits and the other is harmed.
- $E$: Amensalism $(-,0)$: One species is harmed and the other is unaffected.
Statement $A$ is incorrect because in commensalism $(+,0)$,one species benefits and the other is unaffected.

(B) Sexual deceit is a pollination strategy where a plant mimics the female of a specific insect species to attract the male of that species for pollination. The orchid 'Ophrys' employs this mechanism by mimicking the female bumblebee in both morphology and scent,thus deceiving the male bumblebee during its attempted copulation.