Answer: gastrula, archenteron, blastospore
Explanation:
a) Gastrulation is a dramatic reorganization of the hollow blastula into a two-layered or three-layered embryo called a gastrula.
b) Invagination of cells into the blastocoel forms a tube called the archenteron.
c) The open end of the archenteron is called the blastospore..
Answer:
A cell is the smallest unit of a living thing. A living thing, whether made of one cell (like bacteria) or many cells (like a human), is called an organism. Thus, cells are the basic building blocks of all organisms.
Explanation:
Answer:
What was the question of it
Answer:
e. All of the above are correct.
Explanation:
Active transport is a type of transport in living systems in which molecules/ions/substances are moved or transported against their concentration gradient i.e. from a region where the substance is LOW to a region which it is HIGH, across a membrane. Since molecules are transported across a memembrane against their concentration gradient, an energy input in form of ATP is needed to do so.
Active transport is used in living systems to transport out secretory products and waste material against concentration gradients, take up nutrients from the environment against concentrations gradients etc. Since ions are substance moved by active transport from a low region to high region, there is an imbalance in the intracellular concentration of ions, such as Na, K etc.
Since there is no equilibrium in the concentration of ions on opposite sides of the membrane, an electric potential is formed across the membrane i.e. one part of the membrane will be more positively charged than the other.
They can distinguish whether the entity is living or non living by checking whether they have all the seven characteristics of living things.
These 7 characteristics include:
Movement
Respiration
Sensitivity
Growth
Reproduction
Excretion
Nutrition.
If the entity does show all these seven characteristics, it should be a living organism.
In the past, scientists by using these 7 characteristics, they sorted living things in 5 kingdoms(plus virus), each with their own other characteristics.
