Answer:
The correct answer would be plasma membrane or cell membrane.
Plasma membrane is phospholipid bilayer structure which separates the intra-cellular components from extra-cellular environment.
One of the most important characteristics of the plasma membrane is that it is selectively permeable in nature.
It allows some substances to move freely in and out of the cell while restricts the movement of other substances. It is similar to function of security guard who decides whom may enter and whom may not.
Small molecules and uncharged particles can travel across the plasma membrane easily by simple diffusion. For example, exchange or diffusion of gases (carbon dioxide and oxygen) across the cell. The movement of such substance depends upon its concentration gradient across the membrane.
Charged particles and large sized substances require protein channels to travel across the cell. Such substances are transported either with the help of facilitated diffusion or active transport.
Answer: A kid or a billy
The correct macthing of the organs with their organ systems is as follows.
1. Digestive system - intestines.
2. Central nervous system - brain.
3. Respiratory system - tracheal system.
4. Excretory system - bladder.
Digestive system is made up of the alimentary canal consisting of the digestive organs and the glands. Among the digestive organs, the intestines play a major role in the process of digestion. The small intestine is the site of complete digestion which is associated with the pancreas and liver. The large intestine is involved the absorption of water from the digested food and remaining waste material is stored and thrown out of the body during defecation.
The central nervous system is made up of the brain and the spinal cord. The brain makes the largest part and the functional of the central nervous system. It controls most of the activities of the body. It is made up of three parts called the cerebrum, cerebellum and medualla oblongata and is protected by the skull.
The respiratory system is divided into the upper respiratory tract consisting of the nasal cavity, pharynx and larynx, and the lower respiratory tract consisting of the trachea, bronchi, bronchioles and the alveoli. The trachea or the wind pipe is a cylindrical tube infront of the oesophagus, supported by 16-20 C-shaped hyaline cartilage. It serves as a passage for air to move in and out of the lungs.
The excretory system is made up of a pair of kidneys, a pair of ureters, an urinary bladder and an urethra. The urine produced by the kidney flows through the ureters and is collected in the urinary bladder. A spinchter (a ring of muscle) guards the opening of the bladder into the urethra and relaxes only at the time of urination under the impulse from the brain.
B. animal cell
C. cell membrane
D. DNA molecule
The study of the DNA molecule was instrumental in the formulation of the modern cell theory.
The contemporary cell theory, a key idea in biology, asserts that all living things are made up of one or more cells, that cells are the essential building blocks of life, and that all cells develop from already-existing cells. This notion was developed in large part as a result of research into the DNA molecule.
Significant insights into the mechanisms underpinning cellular operations and heredity have been gained through understanding DNA's structure, function, and involvement in genetic inheritance. The notion that cells are the basic unit of life and carry the genetic information essential for an organism's growth, development, and survival was further cemented by findings linked to DNA replication, gene expression, and mutations.
As a result, the comprehensive and widely embraced contemporary cell theory was made possible by research into the DNA molecule.
To know more about DNA here brainly.com/question/16099437
#SPJ2
A cell wall was instrumental. Hope I helped!
producers
b.
omnivores
c.
herbivores
d.
consumers
All animals are considered consumers because they eat producers, in the tropic level there are several layers that are primary, secondary, and tertiary consumers, hence option D is correct.
Consumers are defined as an organism, they do not synthesize their own food and depends on the consumers, in the ecosystem plants are considered producers, that are eaten by animals (consumers).
Plants are producers, they are able to synthesize organic material with the help of photosynthesis and this provides energy to the other organism that consumes these plants.
In every topic level in the energy pyramid, each organism depends on another tropic level for energy needs, the consumer depends on their energy need to producers.
Therefore, it is suggested that all animals are consumers.
Learn more about consumers, here:
#SPJ2