Newton's First Law states that an object will remain at rest or in uniform motion in a straight line unless acted upon by an external force. It may be seen as a statement about inertia, that objects will remain in their state of motion unless a force acts to change the motion.
Answer:
Both facilitated diffusion and active transport are selective processes. Only selective molecules are allowed to cross the membrane. They utilize carrier proteins to move across the membrane.
Explanation:
Diffusion is the process by which molecules move across a membrane respective of the concentration gradient. The plasma membrane is a <em>selectively permeable membrane</em> which allows specific molecules to move across the concentration gradient.
Molecules migrate from a region of higher concentration to a lower concentration in case of diffusion. It can be classified into simple diffusion and facilitated diffusion. These are examples of <em>passive transport</em>.
In facilitated diffusion molecules move across the concentration gradient with the help of <em>carrier proteins or channel proteins</em>. The carrier proteins bind to the molecule which has to be transported and change conformation to allow it to cross the membrane. For example glucose molecule is carried across through <em>GLUT transporter</em>. <em>Channel proteins</em> open a channel inside the membrane and molecules get transported across the gradient.
Active transport carries molecules against the concentration gradient with the assist of energy. ATP hydrolysis is utilized to generate energy. As a result of active transport, the molecules are aggregated on one side of the membrane.
Answer:Characteristics of Protists.
Explanation: Like all other eukaryotes, protists have a nucleus containing their DNA. They also have other membrane-bound organelles, such as mitochondria and the endoplasmic reticulum. Most protists are single-celled.
Humans have approximately 20 000 genes, while they have only 46 Chromosomes - so we see there are a lot more genes than chromosomes and there must be multiple genes per chromosome - <span>B. Every chromosome is made up of many genes.
In fact, we know quite a lot about our chromosomes, but we don't even know how many genes exactly we have!</span>
