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3 years ago

How placenta is design to provide nutrition to developing embroy

1 answer:

5 0

The placenta is the interface between the maternal and embryo's blood, and allows for the exchange of nutrients, including oxygen and carbon dioxide exchange, but prevents certain drugs and chemicals from reaching the embryo. Its a bit like a security guard that only lets certain things though to the baby.

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As a species evolve, they develop ________ and ________ others

Leno4ka [110]

Your answer would be: New traits, lose. This is because evolution is when a species changed and adapts to changes in their environment. During this process, they may lose old traits that are no longer useful.

8 0

3 years ago

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The conversion of malate to oxaloacetate in the citric acid cycle takes place with the conversion of NAD to NADH. In this reacti

Mariana [72]

Answer:

a) the oxidizing agent.

Explanation:

In the citric acid cycle, malate is dehydrogenated into oxaloacetate and the reaction is catalyzed by malate dehydrogenase. The released electrons are accepted by NAD+. So, NAD+ is reduced into NADH. The substances that accept electrons during chemical reactions and are reduced to oxidize the other substances are called oxidizing agents. NAD+ serves as an oxidizing agent as it accepts electrons to oxidize malate into oxaloacetate.

5 0

2 years ago

1. Flower position, stem length, and seed shape are three characters that Mendel studied. Each is controlled by an independently

maria [59]

Answer:

a. 1/64 AATTDD

b. 1/64 aattdd

c. 8/64=1/8 AaTtDd

d. 2/64 = 1/32 AATTDd or aattDd or AAttDd or aaTTDd

Explanation:

Available data:

Flower position: Axial (A) is dominant to Terminal (a)

Stem length: Tall (T) is dominant to dwarf (t)

Seed shape: Round (R) is dominant to wrinkled (r)

Cross:

Parental) AaTtDd x AaTtDd

Knowing that these four genes assort independently, then we can infer that the F1 will have the next genotypic proportions for each gene:

AA= 1/4

Aa =2/4

aa = 1/4

TT = 1/4

Tt = 2/4

tt = 1/4

DD = 1/4

Dd = 2/4

dd = 1/4

This is the same as developing a Punnett square for each gene separately.

Knowing this, to get each of the mentioned genotypes for each trait, we must multiply their respective genotypic proportions, like this:

a. homozygous for the three dominant traits, AATTDD

AA1/4 x TT 1/4 x DD 1/4 = AATTDD 1/64

b. homozygous for the three recessive traits, aattdd

aa 1/4 x tt 1/4 x dd 1/4 = aattdd 1/64

c. heterozygous for all three characters, AaTtDd

Aa 2/4 x Tt 2/4 x Dd 2/4 = AaTtDd 8/16=1/8

d. homozygous for axial and tall, heterozygous for seed shape. There are four possibilities, all of them with the same result:

AATTDd --> 1/4 x 1/4 x 2/4 = 2/64=1/32

aattDd ---> 1/4 x 1/4 x 2/4 = 2/64=1/32

AAttDd ---> 1/4 x 1/4 x 2/4 = 2/64=1/32

aaTTDd ---> 1/4 x 1/4 x 2/4 = 2/64=1/32

4 0

3 years ago

Read 2 more answers

Which elements are likelyto gain electrons?

stiks02 [169]

Answer:

Elements that are metals tend to lose electrons and become positively charged ions called cations. Elements that are nonmetals tend to gain electrons and become negatively charged ions called anions

Explanation:

3 0

3 years ago

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New Zella article called: how chromosome mutations occur. There are four questions on the quiz I can't get any of them. Please h

nadezda [96]

Answer:

Change in the structure of chromosome.

Explanation:

Chromosome structure mutations are the changes that occur in the structure of chromosomes rather than just individual nucleotides. These mutations occurs due to the errors that happens in cell division that leads to the breaking in section of a chromosome, which can be duplicated or move onto another chromosome. Chromosome mutation is the process of change in the chromosomes that occurs due to the rearranged chromosome parts and abnormal numbers of individual chromosomes.

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2 years ago