Answer:
Option-D
Explanation:
In the given question the genotype of parental allele is- AbaB X AbaB. The alleles formed will be- AB, Ab,aB, ab in which the crossover allele will be AB and ab.
1. Unlinked genes
Now of these alleles are unlinked then the alleles will assort independently of each other therefore performing the punnett square we will get dihybrid ratio as 9:3:3:1 in which
1. A_B_ are 9
2. aaB_ are 3
3. A_bb are-3
4. aabb- 1
Since the crossover allele are AB and ab therefore A_B_ are 9 and aabb- 1 represent recombinant genotype.
2. Linked genes
When the genes will be linked then chances of crossing over will be reduced as a result of which only two type of allele will be formed which are- Ab and aB and the recombinant frequency will become less.
Crossing these allele will form Aabb
, AaBb
, AaBb and aaBB genotypes.
The recombinant ratio will decrease as A_B_ is 2 and aabb is not present.
Thus, option-4 which states that the unlinked ration is 9:3:3:1 and linked ratio is <9: >3: >3: <1 is correct.
The both have 8 arms, the squid has an extra 2 tentacles though.
Answer: Why?
Explanation: I hope you are okay.
Answer:
A neuron that has only one axon but several dendrites is classified as:
a. multipolar neuron.
Explanation:
- The neurons are the fundamental unit of the nervous system.
- The nervous system consist of only two types of cell; neurons and neuroglia.
- Neurons are specialized to respond to physical and chemical stimuli, conduct nerve impulse and release neurotransmitter , while the neuroglia supports , nourish and protect the neuron.
- Most neurons have three parts: a cell body, dendrites and axon.
- Neurons show a great diversity in size and shape, and are classified on the basis of structure and function.
On the Basis of structure the neurons are classified as: unipolar, bipolar and multipolar. (Multidendritic neurons are studied in <em>Drosophilla </em>and are reported to be a result of misexpressed<em> gene</em>)..
- Multipolar neurons are the most common type of neurons in the brain and spinal cord and have several dendritic processes and one axon.
- Bipolar neurons are found in retina of the eye, in the inner ear and in the olfactory area of the brain and are characterized by one dendrite and one axon.
- Uni-polar neurons have single processes extending from the cell body which divide into two branches.
On the basis of function neurons are classified as; sensory, motor and association neurons.
