Answer:
Sexual reproduction
Explanation:
In asexual reproduction, the same genes are transferred to the next generation because there is no combination of genes takes place so the rate of variation is very less in asexual reproduction and in sexual reproduction combination of different genes from two different parents occurs which give rise to genetic variation.
So when the plant is put in an environment where harmful bacteria are present then it will prefer sexual reproduction to bring variation in its genome so that it can get the ability to fight against these pathogenic bacteria.
The plants that reproduced asexually will be eradicated by pathogens because they can not get the new genes to fight against the pathogen due to lack of appropriate variation in their gene.
Answer:
organism take food to get different types of nutrition which gives energy to the them and also it helps for growth and nourishment of cell
Plants:
1. Most plants respond to the environment by growing towards the light.
2. Plants respond to daily and seasonal cycles and diseases.
Flatworms:
1. Flatworms respond to changes in light.
2. Flatworms adapt to marine life by using diffusion to breathe and to distribute nutrients to other parts of the body.
Humans:
1. The nervous system allows an organism to respond quickly to changes in the internal or external environment.
2. Some humans modify the environment (positively or negatively), such as cutting forests, building dams, and expanding urban areas, etc.
Answer: C. It provides information about what is already known about a particular research question.
Background research is a research which is done before designing a new research plan. This involves a review of complete history and nature of research problem with respect to the existing literature. Therefore, background research provides already known information about a particular research.
Some Lampreys are anadromous from their lake and they migrate up rivers to spawn.
Explanation:
If the adult fish live in the sea and migrate into fresh water to spawn is known as anadromous and if the adult fish live in fresh water and migrate into salt water to spawn is known as catadromous.
An anadromous fish like salmon, smelt,shad spends most of their life in the sea and returns to fresh water to spawn. A catadromous fish like eels lives in fresh water and enters salt water to spawn.
Sea lamprey brings nutrients into fresh water and provide a source of food for various birds, fish, mammals and people. The newly transformed lamprey can live only for few months in fresh water .
The females deposit a large number of eggs in nest made by males in the streams with strong current. Spawning is done by death of the adults
