Vertebrates have a back bone. They have living endoskeleton, pharnyx and efficient respiration, advanced nervous system, and paried limbs.
I think your answer should be B. an organism. Hope this helps. =^-^=
Answer:
Homology refers to the similarities between the group of species that share the common ancestor. The homology individuals arise from a common ancestor. They shows divergent evolution. The basic structure in homology is similar. The organs perform different function. They occur due to the evolutionary process.
Homoplasy refers to the shared characters of the group of species that do not share the common ancestor. The homoplasy do not involve the common ancestor. They shows convergent evolution. The basic structure in homoplasy is different. The organs perform the similar function. They occur due to the adaptation in different habitats.
The fossil records of primitive plants show a variety of seed dispersal mechanisms that has been adopted by plants at various stages and how they have evolved. The most primitive of this seed dispersal mechanism is the Anemochory
Anemochory is the dispersal of seed through the wind. The seeds have wing like structures and are lightweight to be able to fly away with the wind. They are dull colored and are pale that will prevent the seed from being visible.
Hydrochory is the next order of evolution of the seed dispersal mechanism which became majorly adopted by plants that tend to grow near water sources and those whose seeds are too heavy to fly in the air. One of the best examples is the coconut that falls off on the sea water in the coastal areas and floats to other lands and sprouts to a new plant.
Barochory is the dispersal of the seed through gravity. This is the mechanism where the fruit falls off to the ground due to gravity and grows into a new plant.
Endozochory is the dispersal of the seed through animals. In this case the seed is usually covered with a fleshy edible part which is consumed by the animals and in this process the seed goes into the digestive system of the animal and is excreted in a different place from where the seed can sprout into a new plant.
Ballochory is the dispersal of the seed due to the forceful ejection of the seed by explosive dehiscence of the seed. This lets the plant to place its seeds in a distant area. One of the best examples is the Hura Crepitans which is also called the dynamite tree, named after its exploding fruits.
Answer:
The correct answer is- Immune system
Explanation:
There are physical, chemical and immunological barriers present in our body which helps us to protect from the foreign antigen. They all assist each other and helps in pathogen removal from our body.
The physical barrier includes skin, gastrointestinal tract, respiratory tract, etc which do not allow the microbe to enter the body. Chemical barriers include tear, saliva, acid in the stomach which kills microbes on the body surface.
Immune cells like macrophages, B cells kills microbes when it gets in the body. Lymphatic system also contain immune cells and helps in microbe removal.
So the immune system is assisted by physical barrier, chemical barrier, and lymphatic system.
