Question

1.why do the animal cells not have a cell wall?
2.why is blood considered a connective tissue?
3.what is serum?
4.which type of tissue is most abundant in animals?
5.what is division of labor?

Answer 1

animal cell do not have a cell wall because they require to change thier shape and the function of cell wall is to provide shape.
blood is considered as a connective tissue because it connect all the body parts to the heart and vice versa.
connective tissue is most abundant in animals
division of labour is the division which tells cell its work.

Answer 2

1.Plants have cell walls made up of cellulose which function in the support and protection of the cell.

Animals have only cell membranes made up of phospholipid bilayer and protein which protects and hold together the cell and its parts, it does not need to provide the support that plant cell was provide because animals have other forms of support ( i.e. exoskeletons and endoskeletons) and the lack of the cell wall allows for increased flexibility and advanced cell/tissue specialization, which plants cannot achieve.

Bacterial cell walls are made up of peptidoglycan and provide support for the cells much like plant cell walls.
2.Blood is considered a connective tissue for two basic reasons: (1) embryologically, it has the same origin (mesodermal) as do the otherconnective tissue types and (2) blood connects the body systems together bringing the needed oxygen, nutrients, hormones and other signaling molecules, and removing the wastes.
3.an amber-coloured, protein-rich liquid which separates out when blood coagulates.
4.connective tissue
5.division of labor is the assignment of different parts of a manufacturing process or task to different people in order to improve efficiency.