The first scientist to classify living things into two main groups

Your first cousin died of tay-sachs disease (autosomal recessive, incidence 0.09%). you are not affected, nor is anyone else in

AlexFokin [52]

<span>25%

Starting from my First cousin family, I know for sure that the Uncle is is a carrier (Aa) and he must have married a wife who is also a carrier (Aa) and that is how they got an affected son. Thus, this leads to the fact that either both of my grandparents are carriers (Aa x Aa) or only one of them is a carrier (Aa x AA). As a result, the chances that my mom (who is related to the uncle who has a defected child) is a carrier is either (2/3 or 1/2) depending if my grandparents genotype, respectively. Thus, if my mom chances of being a carrier is 1/2 then my chance of being a carrier is 1/4. (given that my dad is not a carrier b/c CF is a rare disease) However, if my mom chance of being a carrier is 2/3 then my chance of being a carrier is (2/3)x(1/2)=(1/3) As a result, I could either be 1/4 or 1/3. But since the answer only provide the choice of 1/4 and not 1/3. This leave 25% is the correct answer.</span>

5 0

4 years ago

Read 2 more answers

For plants and other organisms to develop differences among their respective species the alleles of their genes must contain var

olasank [31]

A) <u>Mutation</u> is the original source of variations for plants and other organisms which develops differences among their respective species

Explanation:

Genetic variation leads to the natural differences between each individual and among individuals of a species. The main cause for this variation is due to alleles that cause variations in the composition of genes or the DNA sequences.

A mutation is a genetic variation which leads to the creation of a new allele in a species population. Each variation in the DNA sequence leads to an allele formation and each allele leads to a difference in character or trait between individuals since they are the alternate version of the original genes.

Although genetic variations could be brought about by crossing over, random fertilization, or independent assortment; mutation is the original source because it provides the basic raw material for all the evolutionary changes.

8 0

3 years ago

The state of maintaining a stable internal environment regardless of changing external conditions is called

Nostrana [21]

Answer:

homeostasis

Explanation:

5 0

3 years ago

Can a person’s genotype be determined by their phenotype? Why or why not?

julsineya [31]

Answer:

No, a person's genotype cannot be determined solely by their phenotype as many genes in our genome do not get expressed.

Explanation:

4 0

4 years ago

In 1985 a biologist counted 750 pine trees in a 250 hectare forest. Using similar counting techniques, the biologist counted 1,2

Alisiya [41]

Answer:

Suppose that we have a given function f(x)

The average rate of change of the function between two values x₁ and x₂ is given by:

$r = \frac{f(x_2) - f(x_1)}{x_2 - x_1}$

a) We want to find the average (rate) of change on the size of population from 1985 to 1995.

We have that:

f(1985) = 750

f(1995) = 1500

Then we have:

$r = \frac{1500 - 750}{1995 - 1985} = 750/10 = 75$

This means that the population of trees increases, in average, at a rate of 75 trees per year.

b) What is the density of trees each year that they were counted?

This will be equal to the quotient between the number of trees and the area.

1985: number of trees = 750 pines

area = 250 ha

Then the density is:

D(1985) = (750 pines)/(250 ha) = 3 pines/ha

So 1985, there were 3 pines per hectare.

1990: number of trees = 1250 pines

area = 250 ha

Then the density is:

D(1990) = (1250 pines)/(250 ha) = 5 pines/ha

1995: number of trees = 1500 pines

area = 250 ha

The density is:

D(1995) = (1500 pines)/(250 ha) = 6 pines/ha

3) now we want to get the average change between 1985 and 1995 in the density, this will be:

$r = \frac{D(1995) - D(1885)}{1995 - 1985} = \frac{6 pines/ha - 3pines/ha}{10} = 0.3 pines/ha$

So, on average, each year the number of pines per hectare increases by 0.3

7 0

3 years ago