Ans.
Sex-linked genes are those genes that found on sex-chromosomes (X and Y chromosomes) and their phenotypic expression for a trait depends on the gender of the offspring.
Most of the sex-linked genes are present on X chromosomes as X chromosomes have more number of genes as they are made up of more DNA as compared to Y chromosome.
However, male individuals are more likely to exhibit the sex-linked traits. It is because most of the sex-linked traits are recessive and males have only one copy of X chromosome, while females have two copies of X chromosome. One mutated copy in male can exhibit the trait, while in females, both of the mutated copies are required to exhibit that trait.
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Answer:</h2>
Following are the examples of the given associations:
- Mutualism- Oxpecker and rhinoceros.
- Commensalism- Birds and tree.
- Parasitism- Sashimi and round worm.
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Explanation:</h2>
- <u>Mutualism</u>- It is a the interaction of two organisms of two different species in which each of them gets benefited from each other. For example- Oxpecker eats the ticks, pests and other parasites present on the body of Rhinoceros and hence both of them get benefited as the oxpecker gets food and in return rhinoceros gets pest control.
- <u>Commensalism</u>- it is a association in which two organisms get interacted in which one get benefited and the other is neither benefited nor harmed. For example birds living on trees generally do not harm tree in any case but in return gets food and shelter from the tree.
- <u>Parasitism</u> in aquatic environment- it is defined as the interaction of two organisms in which a organism lives in or on other organism of another species (its host) and benefits by deriving nutrients from the host at the host's expense. For example round worm or tapeworm obtain food and even complete their life cycle inside fishes like Sashimi and harms them.
Result: The above are the examples of the given associations.
They look for facts to confirm their hypothesis then they look for patterns in the data .
