Answer:
C. 444 Ma
Explanation:
The first plants that managed to colonize the land appeared around 470 million years ago, while the first arthropods on land appear i the fossil records around 450 million years ago, so we can say that around the period of 444 million years ago they were well established on land. The first arthropods that started to have terrestrial life were almost identical to those in water, with only minor changes that enabled them to breathe and move more easily. The first plants on land were non-vascular plants. They were small as they initially didn't had deep and well established roots.
Answer:
D
Explanation:
Biomes are large divisions on earth based on climatic patterns, soil types, and the animals and plants that inhabit an area. Examples are aquatic and desert biomes
Ecosystems are interactions between communities (biotic elements) and abiotic elements in their environment.
A population is made up of individuals of the same species
Answer:
Bone marrow transplantation
Explanation:
Stem cells are special cells generated in bone marrow. This can changed into different types of cells. They are red blood cells It carries oxygen to the body cells
.White blood cells Resisting agents from infections
. Platelets it performs clotting of blood
Stem cell transplant involves in removing of damaged cells instead placed stem places from blood or bone marrow
Answer:
246
Explanation:
Increased amount / current population = 972
Amount released = 108
time(t) = 2years
Using the exponential growth function :
f(t) = A*g^t
Where g = growth rate
To obtain the growth rate = g
972 = 108 * g^2
g^2 = 972 / 108
g^2 = 9
g = 3
To determine population after 9 months :
9 months to years = (9/12) = 0.75
t = 0.75
f(0.75) = 108*(3^0.75)
f(0.75) = 108 * 2.2795070
f(0.75) = 246.18676
= 246
Answer:
According to the “hygiene hypothesis,” the problem with extremely clean environments is that they fail to provide the necessary exposure to germs required to “educate” the immune system so it can learn to launch its defense responses to infectious organisms. Instead, its defense responses end up being so inadequate that they actually contribute to the development of asthma.
Explanation:
