BIOLOGY HIGH SCHOOL

According to Figure 13-2, if 25 percent of the parent material remains in a rock sample, how many half-lives have occurred?

Answers

Answer 1

Answer:

Answer: Number of half lives occurred 2.

Explanation:

Let the initial concentration be x

Concentration left=25 % of the x= $x(25)/(100)=(x)/(4)$

To calculate the number of half lives, we use the formula:

$a=(a_o)/(2^n)$ ..(1)

where,

a = amount of reactant left after n-half lives = 0.0495 moles

$a_o$ = Initial amount of the reactant = 0.7924 moles

n = number of half lives

$(x)/(4)=(x)/(2^n)$

taking log both sides

$\logx-\log4=\logx-n\log2$

$\log4=n\log2$

$\log(2)^2=2\log2=n\log2$

n = 2

Number of half lives occurred 2.

Answer 2

Answer: 2 half lives.A half life is when a substance is broken down by half. 100% -> 50% etc.

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Is cytokinesis a part of mitosis

Answers

Cytokinesis is part of M-phase, but not part of Mitosis. M-phase consists of nuclear division (mitosis) and cytoplasmic division (cytokinesis). And yes, telophase is part of mitosis, so it's in M-phase too.
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Two main proteins found in muscle area. smooth and skeletal.
b. tendons and ligaments.
c. actin and myosin.
d. myoﬁbrils and ﬁbers.

Answers

The answer is C: actin and myosin

Answer:

c. actin and myosin

This aquarium exhibits biotic and abiotic factors in an aquatic environment. One of the abiotic factors isA) coral.
B) fish.
C) plants.
D) water.

Answers

Answer: Option 'D' is correct.

Explanation:

Abiotic factors are those factors which are not alive yet they are essential for survival of lives on earth.

Like water, sun, air, land etc.

Without abiotic factors, living organisms and ecosystem get affected.

Hence, water is the correct answer.

D.) water
because water isn't living. anything that breathes, has a pulse, heart, lungs, e.c.t, is living, and anything that is produced by the living organism is also biotic as well.

Researchers have reported that the number of different species of fish found in certain areas of the ocean has been greatly reduced over the past 50 years. Give a reason, other than overfishing, that may be the cause of this decline.

Answers

one reason may be an invasive species coming in and eating while not having a natural fish coming in and eating it so whatever it eats the population drops

Suppose that a dominant allele (P) codes for a polka-dot tail and a recessive allele (p) codes for a solid colored tail. In addition, suppose that a dominant allele (L) codes for long eyelashes and a recessive allele (l) codes for short eyelashes. If two individuals heterozygous for both traits (tail color and eyelash length) mate, what's the probability of the phenotypic combinations of the offspring? A. 1:1 ratio (half are polka-dot tails and long eyelashes; half are solid tails and short eyelashes) B. 1:1 ratio (half are polka-dot tails and short eyelashes; half are solid tails and long eyelashes) C. 9:3:3:1 ratio (9 polka-dot tails and long eyelashes, 3 polka-dot tails and short eyelashes, 3 solid tails and short eyelashes, 1 solid tail and short eyelash) D. 9:3:3:1 ratio (9 polka-dot tails and short eyelashes, 3 polka-dot tails and short eyelashes, 3 solid tails and long eyelashes, 1 solid tail and long eyelash)

Answers

Heterozygous is when an individual has two different alleles at any location. In this example, each parent will have Pp for tail type and Ll for eyelash length.
The punnet square for couple will look like this

PL    Pl   pL   pl

PL PPLL PPLl PpLL PpLl

Pl   PPLl PPll PpLl Ppll

pL PpLL PpLl ppLL ppLl

pl   PpLl Ppll ppLl ppll

Of the sixteen genotypes listed, the following phenotypes will result

Polka dot tail with long eyelashes 9
Polka dot tail with short eyelashes 3
Solid tail with long eyelashes 3
Solid tail with short eyelashes 1

I want to say the answer is (C), but it looks like there might have been an error in the question where it says 3 solid tails, short eyelashes and then 1 solid tail with short eyelashes

9:3:3:1 ratio (9 polka-dot tails and long eyelashes, 3 polka-dot tails and short eyelashes, 3 solid tails and long eyelashes, 1 solid tail and short eyelash)

African elephants flap their large ears to cool off. Which biology theme does this phenomenon represent?

Answers

When an elephant flaps its ears to cool off, it is using a behavioral response to adapt to their environment/temperature

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