Answer: Option B
Explanation: The first line of defense acts a barrier and does not allows the foreign materials to enter inside the body. It includes chemical and physical barriers that are always ready to protect the body from infection.
Example: Skin and mucous membrane.
Skin is largest organ and it acts as a barrier between pathogens and human body. It acts a waterproof material and the pathogens cannot get inside through skin unless the skin is broken.
Mucous membranes also acts as first line of defense and breaks the cell wall of many bacteria entering through the openings of the body.
So, skin and mucous membrane are the first line of defense.
Answer:
A. anther
B. receptacle
C. sepal
D. petal
F. filament
H.
J.
K. pollen tube
L.Ovary
O. Ovule
P. Style
* I'm confused with H and J
Models can be used to predict or explain events is the statements accurately describe models in science.
Explanation:
- Scientific modeling is also known as a scientific activity. The aim of the modeling can understand easier, define, quantify, visualize. Scientific knowledge gives a common knowledge to everyone.
- Normally, Science is a subject which cannot clearly explain moreover it is to be interpreted.
- There are different types of models present some of them are mathematical models, graphical models, operational models, etc.
- Scientific models are increasing in the fields of science education and Philosophy of education.
<span>it decomposes dead organisms, fixes nitrogen, and can break down some petroleum. and it can infect something and decrease its chance of survival.
Bacteria plays an important role in the environment. It decomposes dead organisms, fixes nitrogen, and </span>can break down some petroleum. It can also infect 'something' and decrease its chance of survival.
