i'm a little unsure about my answers for these questions. Can someone please check them for me?, thanks.:

15. All of the following are major interactions between species EXCEPT
a. competition and mutualism
b. predation and parasitism
c. commensalism and competition
d. adaption and dispersion

D

21. Which of the following is one of the main properties used to describe a population?
a. number of individuals
b. variations in hybrids
c. number of species
d. kind of adaptions

A

____

10. Each of the following is an example of a parasite EXCEPT
a. a roundowrm in a human's intestine
b. a cow in a pasture
c. a tick on a cat
d. mistletoe on a tree

D

Thank you once again

I agree with your first two answers.

But rethink the meaning of parasite for your last answer. You may also want to look up mistletoe.

Certainly! Here's an explanation for each of the questions:

15. The question asks for the option that does NOT represent a major interaction between species. To determine the correct answer, let's analyze the provided options:

a. Competition and mutualism: Competition refers to the struggle for resources among individuals of the same or different species, while mutualism refers to a mutually beneficial interaction between different species. Both of these are major interactions between species.

b. Predation and parasitism: Predation is when one organism (predator) kills and consumes another organism (prey), while parasitism is a type of symbiotic relationship in which one organism (parasite) benefits at the expense of the other organism (host). Both of these are major interactions between species.

c. Commensalism and competition: Commensalism is a type of symbiotic relationship in which one organism benefits while the other is neither harmed nor benefited, whereas competition, as mentioned before, is the struggle for resources. Both of these are major interactions between species.

d. Adaptation and dispersion: Adaptation refers to the process by which organisms change or develop certain traits to better survive in their environment, while dispersion refers to the distribution or spread of individuals across an area. Neither of these represents an interaction between species.

Therefore, based on the above analysis, the correct answer is option D: Adaptation and dispersion.

21. The question asks for one of the main properties used to describe a population. Let's examine the given options:

a. Number of individuals: This is indeed one of the main properties used to describe a population. It refers to the total count of individuals within a specific area.

b. Variations in hybrids: Although variations in hybrids can occur within a population, they are not one of the main properties used to describe a population.

c. Number of species: The number of species refers to species richness, which describes the number of different species in a community rather than a population.

d. Kind of adaptations: While adaptations are important for individual organisms, they are not a main property used to describe a population.

Therefore, the correct answer is option A: Number of individuals.

10. The question asks for the option that does NOT represent an example of a parasite. Let's evaluate the provided options:

a. A roundworm in a human's intestine: Roundworms that inhabit a human's intestine can be considered parasites, as they derive nutrients and benefits from the host while potentially causing harm.

b. A cow in a pasture: Cows grazing in a pasture are not parasites but rather a herbivorous species that obtains food from plants.

c. A tick on a cat: Ticks are parasites that live on the external surface of animals, such as cats, feeding on their blood.

d. Mistletoe on a tree: Mistletoe is a parasitic plant that attaches itself to a host tree and obtains nutrients from it. Therefore, mistletoe represents an example of a parasite.

Based on the above analysis, the correct answer is option B: A cow in a pasture.

I hope the explanations helped! Let me know if you have any more questions.