Biology, 23.11.2020 23:10 kennedy5550

الي متاكد من الاجابه يكتب لوسمحتم بعطيكم ١٥ نقطه و براينلست اذا قدرت

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Answer from: Quest

the african cheetah.

this species has a relatively low level of genetic

variation because the population was reduced to a small size approxi-

mately 10,000 to 12,000 years ago.

chapter outline

24.1

genes in populations and the hardy-

weinberg equation

24.2

factors that change allele and genotype

frequencies in populations

24.3 sources of new genetic variation

population genetics

until now, we have primarily focused our attention on genes

within individuals and their related family members. in this

chapter and chapters 25 and 26 , we turn to the study of genes in

a population or species. the field of

population genetics

is con-

cerned with changes in genetic variation within a group of indi-

viduals over time. population geneticists want to know the extent

of genetic variation within populations, why it exists, and how it

changes over the course of many generations. the field of popu-

lation genetics emerged as a branch of genetics in the 1920s and

1930s. its mathematical foundations were developed by theoreti-

cians who extended the principles of gregor mendel and charles

darwin by deriving formulas to explain the occurrence of geno-

types within populations. these foundations can be largely attrib-

uted to three scientists: sir ronald fisher, sewall wright, and j. b. s.

haldane. as we will see, support for their mathematical theories

was provided by several researchers who analyzed the genetic com-

position of natural and experimental populations. more recently,

population geneticists have used techniques to probe genetic

variation at the molecular level. in addition, staggering advances

in computer technology have aided population geneticists in the

analysis of their genetic theories and data. in this chapter, we will

explore the genetic variation that occurs in populations and con-

sider the reasons why the genetic composition of populations may

change over the course of several generations

Answer from: Quest

Atp is is our little "pocket" of energy. of course, if you have too little, then it means you have too little energy, and you'll pass out. the way to not have enough, is to have no energy sources (glucose, fats, proteins). you can't have too many atp molecules. cycles like the krebs cycle produce it, but if you have too much of any substrate (or too little for that matter), the cycle stops and atp is no longer made (it stops until substrate levels are such that the process can go on). in any case, this is unlikely since atp is constantly hydrolyzed and remade, even while you're asleep. you won't have too much. if you have zero, you are dead or dying.

Answer from: Quest

Proteins are the workhorses of the cell, controlling virtually every reaction within as well as providing structure and serving as signals to other cells. proteins are long chains of amino acids , and the exact sequence of the amino acids determines the final structure and function of the protein. instructions for that sequence are encoded in genes . to make a particular protein, a messenger ribonucleic acid (mrna) copy is made from the gene (in the process called transcription ), and the mrna is transported to the ribosome . protein synthesis, also called translation , begins when the two ribosomal subunits link onto the mrna. this step, called initiation, is followed by elongation, in which successive amino acids are added to the growing chain, brought in by transfer rnas (trnas). in this step, the ribosome reads the nucleotides of mrna three by three, in units called codons , and matches each to three nucleotides on the trna, called the anticodon. finally, during termination, the ribosome unbinds from the mrna, and the amino acid chain goes on to be processed and folded to make the final, functional protein

Answer from: Quest

yes, because even though a theory has a lot of evidence to support it, it is not always true