Biology Answers

Explain what is meant by the term ‘linked genes’ with respect to homologous recombination.

Question 5: Which organ and cell type are primarily affected by the mutation? Is this consistent with the symptoms observed in SCA1 patients?

Mice are generally a good model for human diseases, if you wish, you can read more about the benefits of the mouse model on The Jackson Laboratory website  <span style="color:#E90167">Advantages of the mouse as a model organism</span>.

Mouse models of SCA1 have been developed and helped researchers to understand this disease and to experiment with new treatments.

Mr A., 65 years old male, was gardening at home when he suddenly experienced 

slurred speech, weakness of left upper and lower limbs. He was found to have 

decreased power of the left upper and lower limbs and a high blood pressure. 

Discuss the condition he might be suffering from, the blood vessels involved, and 

the cortical areas involved and the prognosis. 

Describe the hypothesized steps for the evolution of eukaryotic cells via endosymbiosis. How is evidence used to support this theory? Explain your position.

1.Why do humans get rabies vaccine after exposure and infection? Why getting this vaccine isn't like getting the other vaccines like covid vaccine?(because we know that we get other vaccines before infection) 2. Why don't humans get rabies vaccine in multiple doses and routinely like animals?

The Ras protein functions as a molecular switch that is set to its “on” state by other proteins that cause it to release its bound GDP and bind GTP. A GTPase-activating protein helps reset the switch to the “off” state by inducing Ras to hydrolyze its bound GTP to GDP much more rapidly than it would without this encouragement. Thus, Ras Works like a light switch that one person turns on and another turns off. You are studying a mutant cell that lacks the GTPase-activating protein. What abnormalities would you expect to find in the way in which Ras activity responds to extracellular signals?

Assume a three point cross in which the F1 aa ⁺ bb⁺ Dd⁺ was crossed to aabbdd and the offspring had the following genotypes:

GENOTYPES Number

aa ⁺ bb⁺ Dd⁺ 621

aa ⁺ bb⁺ Dd⁺ 3

aa ⁺ bb⁺ Dd⁺ 64

aa ⁺ bb⁺ Dd⁺ 103

aa ⁺ bb⁺ Dd⁺ 109

aa ⁺ bb⁺ Dd⁺ 57

aa ⁺ bb⁺ Dd⁺ 7

aa ⁺ bb⁺ Dd⁺ 608

i. Indicate the parental and recombinant genotypes

ii. Indicate the double recombinants

iii. Costruct a genetic map of these three loci, including their order and map distance bewteen them. 

Assume a three point cross in which the F1 aa+ bb+ Dd+ was crossed to aabbdd and the

offspring had the following genotypes:

GENOTYPES Number

aa ⁺ bb⁺ Dd⁺ 621

aa ⁺ bb⁺ Dd⁺ 3

aa ⁺ bb⁺ Dd⁺ 64

aa ⁺ bb⁺ Dd⁺ 103

aa ⁺ bb⁺ Dd⁺ 109

aa ⁺ bb⁺ Dd⁺ 57

aa ⁺ bb⁺ Dd⁺ 7

aa ⁺ bb⁺ Dd⁺ 608

What are the veins in fishes that bring blood from the fins?