Describe four types of point mutations: transitions, transversions, deletions, and additions.

Biology

1 answer:

IgorLugansk [536]4 years ago

8 0

Explanation:

Mutation - any sudden and hereditary change in the genetic set of an organism, which is not explained by the recombination of pre existing genetic variation. Point mutation - Changes in the nucleotide sequence, which alter the amino acid sequence in the polypeptide chain encoded by the gene, leading to a phenotypic change.

When a purine base is replaced by another purine base (A by G or vice versa) or a pyrimidine base is replaced by another pyrimidine base (T by C or vice versa) it is called a transition. In contrast to the transitions we have the so-called transversions, which are mutations where a purine base is replaced by another pyrimidine, or vice versa, that is, a pair C-G is replaced by another A-T or vice versa. It may be a simple substitution of a base pair, which may be by deletion or addition of one or a few bases. Deletion: is the loss of a portion of the chromosome, resulting in the lack of one or more genes

You might be interested in

Sequence the events that take place when a motor neuron's action potential triggers a muscle contraction.

Serhud [2]

Answer:

A,C,F,E,D,B

Explanation:

The is the sequence of action potential transmission at at the neuromuscular junction. Generally the arrival of action potential from the presynptic neuron caused influx of ca+ which causes migration and the release of the the acetycholine to the synaptic cleft.

The acetycholine binds with the receptors on the saccolemma to causes opening of Na+ , its influx to causes depolarizarion of the sacolemma. The depolarization of the latter spreads along the transverse tubules, This depolarization causes increases in the permeability of the sacorplasmic reticulum, with opening of ca+ channels and diffusion of Ca+ out of the S. reticulum.

The Ca+ binds to troponin,and tropomyosin exposed the myosin-binding sites on actin filament . The myosin head forms the cross bridges with the filament, and therefore the sacomere shortens leading causing muscle contraction.

3 0

4 years ago

Read 2 more answers

Which is not a property of a mineral?

bekas [8.4K]

<span>From the given options B. Reflection is not a property of the mineral. These properties of the minerals collectively help the researchers determine the identity of the minerals at a primary level. further analysis is done through how the mineral is reacting to the other minerals and at several temperatures.</span>

6 0

3 years ago

Long-distance runners often run 20 kilometers or more at a time. What body systems do you think would be most involved in the en

artcher [175]

I think the most involved would be your circular system because since your running fast you need to pump blood. Your muscular system because your moving a lot and your respiratory system because you need more oxygen

3 0

3 years ago

Two scientists in British Columbia are counting trout spawning grounds (called redds) along 5 km of a stream. The presence of

Eva8 [605]

The most likely reason for the scientists to count different numbers of redd is the observer’s efficiency.

Explanation:

In a field survey based on visual counting for visual stock assessment, the scientists may count a different number of redds each time in the same area due to the observer’s or the scientist’s efficiency.

The same place may first appear as redd and then later may not and accordingly the scientist's count also varies.

This error happens due observer’s inexperience in surveying, misidentification of redd species, changes or variations each time in the redd habitat, survey life, characteristics, spawning shifts etc., and poor temporal and spatial coverage.

8 0

3 years ago

Which of these best explains how Earth's surface features are formed by moving tectonic plates?

Ksju [112]

Answer:Earth's crust is separated into individual plates that float on top of molten material, which causes them to slowly move. Convection currents occur in the atmosphere and oceans.

Explanation:

7 0

3 years ago