Backcross, the mating of a hybrid organism, offspring of genetically unlike parents,with one of its parents or with an organism genetically similar to the parent.
The correct answer is letter A: the circulatory system removes waste from the tissues by converting carbon dioxide-rich blood into oxygen-rich blood that can be circulated throughout the body to support its several functions. Without the lungs the human body will not be able to process converting blood cells into oxygen-rich cells in the body.
It is false cause the embryo develops the baby into whatever mammal offspring is being born
The subcellular structures of neuron that forms the basis for transmission of nerve impulses are the synaptic vesicles.
What are the steps in impulse transmission between neurons?
- The action potential or nerve impulse reaches the <u>axon</u> of neuron and depolarises the membrane.
- Voltage gated Calcium channels open .
- Arrival of action potential causes the synaptic vesicle to attach to presynaptic membrane.
- Calcium influx triggers release of neurotransmitter.
- This neurotransmitters bind to postsynaptic membrane and new impulses are created.
Synaptic vesicle under resting condition:
- The neurotransmitter molecules are stored in synaptic vesicles.
- If the neurotransmitter leak from the vesicles, they are destroyed by enzymes.
- During resting condition, they are placed randomly.
- When an impulse reaches the axon, vesicles are arranged in the presynaptic membrane.
Thus from the above we can conclude that, synaptic vesicles are the subcellular structures in transmission of nerve impulses and , under resting condition they are placed randomly.
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Answer:
Directional selection
Explanation:
Directional selection is a type of natural selection that favors one extreme phenotype of a genetic trait due to its survival and reproductive advantage to the individuals over another extreme phenotype and the intermediate phenotype.
In the given example, the thick-leaved plants are better adapted to a drier climate due to reduced water loss. Directional selection favored the plants with thick leaves which in turn produced more progeny. Over the generations, the population evolved into the one having more number of thick-leaved plants.
