<u>Answer:</u>
Approximately, the oldest stromatolites are 3.6 billion years old on earth.
<u>Explanation:</u>
- Stromatolites is not only oldest earths fossil but conspiracy in that they are singular visual portal in deep time on earth.
- It is defined as laminated accumulation structure that is they stick up above sea floor .
- Stromatolite buildings includes oldest fossils which are 3.5 billions old when the earth were too unfriendly to support life.
- The study of fossil age, evolutionary, method of formation are known as paleontology.
- These specimens are considered as old fossils which are around 3.4 to 4.1 billions years old.
Answer:
The correct answer is "grey; central canal".
Explanation:
Grey matter refers to an area of the brain, brainstem and cerebellum comprised of unmyelinated neurons and other cells that has given its name for having a pinkish-grey color in the living brain. Grey matter is also present in the spinal cord in an are of three grey columns that are H-shaped and it is located around the central canal filled with cerebrospinal fluid
Answer: Alveoli
Explanation: Alveoli of lungs are surrounded by extensive blood capillaries. The partial pressure of oxygen in the alveoli is higher than the blood entering the pulmonary capillaries, hence oxygen moves into the blood. Carbon dioxide in the lungs simultaneously diffuse out of the blood into the alveolar space.
Your answer is "Hydropower uses the kinetic energy of water to generate electricity"
Answer:
A. 3
B. 4
C. 5
D. 6
E. 2
F. 1
Explanation:
1. Integumentary system.
This is an organ system that consists of hair, skin, nails and exocrine glands with receptors that senses the outer stimulus and environmental conditions, through homeostasis maintain stability of the internal environment.
2. Nervous system.
It receives sensory information and signals, convert them to nerve impulses that are transmitted to the body and brain via the spinal cord using nuerons and axons. It also intergrates, retains and analyses information in the brain.
3.Endocrine system.
Secretes hormones and chemicals in response to stimulus from the nervous system to maintain balance using feedback loops i.e, negative and positive.
4. Lymphatic system.
Part of the immune system that consist of vessels that carries lymph, cleaning the blood by filtering lymph with foreign particles into the lymph node.
5. Urinary system.
Used to eliminate waste from the body, regulates blood pressure, volume and pH. It also used to retain electrolytes and metabolites.
6. Respiratory system.
Used for gaseous exchange using the blood, heart and lungs. Air enters the lungs, transported by blood and is pumped by the heart to all body parts where oxygen is dropped, carbon dioxide is collected by the veins to the lungs and released to the atmosphere.
