All categories

2 years ago

How is lactase an example of fitness in humans?

Biology

1 answer:

amm18122 years ago

6 0

$\\$

Evolutionary advantages. Lactase persistence is a text-book example of natural selection in humans: it has been reported to present stronger selection pressure than any other known human gene. However, the specific reasons as to why lactase persistence confers a selective advantage "remain open to speculation".

<h3>WHAT THEY DO IN HUMAN BODY?</h3>

Lactase breaks down the lactose in food so your body can absorb it. People who are lactose intolerant have unpleasant symptoms after eating or drinking milk or milk products. These symptoms include bloating, diarrhea, and gas. Lactose intolerance is not the same thing as having a food allergy to milk.

In pastoralist populations, individuals with the lactase-persistence mutations were more likely to survive, reproduce, and pass on their alleles than people without the mutations, especially in times of famine.

$\\$

Hope It Helps!

You might be interested in

Sylvia added five drops of bromthymol blue to a beaker of distilled water and the solution turned green. Next, she placed a drin

klemol [59]

Answer:

A) acid; [H+].

Explanation:

7 0

2 years ago

Does anyone have a Chegg account?

algol13

No I don’t have it
What is it

5 0

3 years ago

Read 2 more answers

In a plant, leaf color and leaf shape are controlled by two linked genes Leaves of the wild-type plant are red. A recessive muta

Brrunno [24]

Solution :

Red is dominant over the white leaves and pointed is dominant over smooth.

Red = R , white = r

Pointed = P , smooth = p

Red, pointed x white,smooth ------ Parents

RRPP rrpp

RP rp ----------------- Gametes

RrPp -------- $F_1$

(red, pointed)

When this $F_1$ is test crossed,

RrPp x rrpp ---- $F_1$ test cross

Gametes → rp

RP ---------- RrPp - red, pointed - 36 parental type

Rp ---------- Rprp - red, smooth - 14 re- combination

rP ----------- rrPp - white pointed - 10 re- combination

rp ----------- rrpp - white, smooth - 40 - parental type

Total = 100

As this ratio is deviating from 1:1:1:1, it indicated the two genes are linked.

Linkage strength = percentage of crossing over = map distance between the genes.

Percentage crossing = recombination frequency = percentage of recombination.

Recombination frequency $=\frac{\text{total no. of recombination}}{\text{total no. of progeny}}\times 100$

$=\frac{14+10}{100} \times 100$

= 24 %

= 24 map units

4 0

2 years ago

In the Calvin cycle more atp than nadph is used how is this difference made up

Veseljchak [2.6K]

Answer:

Explanation:

The detailed description of photosynthesis is that chlorophyll a becomes oxidized chlorophyll a after being irradiated, and the water in the thylakoid is oxidized by oxidized chlorophyll a to form oxygen and hydrogen ions, and hydrogen ions pass through the class. The ATP synthase on the capsule membrane passes through the membrane into the chloroplast matrix, where it provides a certain chemical potential (ie, an energy produced from a high concentration to a low concentration), and then ADP and Pi on the membrane. Will get energy to form ATP; and NADPH+ is the front chlorophyll a is oxidized by light to release high-energy electrons e, e will be transferred to NADP+ (oxidized coenzyme II), the photolysis of the front water does not produce hydrogen ions? This led to the combination of NADP and H+, which became NADPH.

Next, their use, in front of the photoreaction, in the dark reaction, CO2 will react with the five-carbon compound in the chloroplast matrix, fixed to the formation of a three-carbon compound (one C in CO2, five C in five-carbon compound, Two three-carbon compounds are formed, and then ATP and NADPH supply hydrogen, respectively, and then return to ADP+Pi and NADP+, and the reduced three-carbon compound becomes organic (mostly sugar) and becomes The five-carbon compound will react with CO2 again, which is the Calvin cycle.

Genetic mutation is an important factor that contributes to the pathogenesis and development of Alzheimer’s disease (AD). The genetic factors studied include the dominant mutations of genes encoding amyloid-β precursor protein (APP), presenilin 1 (PSEN1), and presenilin 2 (PSEN2). Additionally, more and more genes have been found to be potentially associated with AD, such as apolipoprotein E (APOE), glycogen synthase kinase 3 beta (GSK3B), dual specificity tyrosine-phosphorylation-regulated kinase 1A (DYRK1A), and Tau. Although many studies on the treatment of AD have not been successful, gene therapy is still considered as a potential way against AD, and some gene-therapy-based therapeutics have entered the clinical trial stage. Existing strategies for gene therapy against AD include gene inactivation, genetic modification, and immunoregulation, etc.

https://www.creativebiomart.net/alzheimacy/therapeutics/gene-therapy/

8 0

2 years ago

Leaves are important plant structures because they

ra1l [238]

The answer is c. Inside leaves, there's a lot of chloroplast, which contains chlorophyll for photosynthesis. This can make energy.

4 0

2 years ago