When parallel rays of light pass through a convex lens the refracted rays converge at one point called the principal focus. The distance between the principal focus and the centre of the lens is called the focal length.

4 0

4 years ago

Only a

ElenaW [278]

Specialists are adapted to fill a very narrow niche in a habitat, and when humans or other wildlife cause their one food to change, then the specialist becomes threatened.

4 0

2 years ago

In the garden pea, tall vine (D) is dominant over dwarf (d), green pod (Y) is dominant over yellow (y) and round seed (W) is dom

siniylev [52]

Answer:

3/8 tall, green, round

3/8 dwarf, green, round

Explanation:

The progeny which are in highest ratio represent parental plants.

Here in the given question, 3 out of 8 progeny are tall, green, round and 3 out of 8 progeny are dwarf, green, round which are the highest in number so they represent parental plants. The reason behind this is that during crossing over only two non-sister chromatids undergo crossing over while two other parental chromosomes remain intact. Out of the 4 chromosome types, 2 remain the same which will result in the same type of genotype of off-springs as of parents. So even if there is 100% chance of crossing over between non sister chromatids still only 50% will be recombinants rest of the 50% will represent parental type.

Another case may be when two genes are very near to each other then it is quite possible that the genes may not undergo crossing over at all in that case there will be no recombinants at all.

So, it simply means that parentals > recombinants or the progeny which are highest in number represent parentals.

In case of unlinked genes, parentals = recombinants. But, recombinants can never be greater than parentals.

6 0

3 years ago

Genetic drift will have a progressively larger impact on allele frequencies in a population as ____.

Tcecarenko [31]

Answer:

population size decreases

Explanation:

3 0

3 years ago