Please help this is a 7th grade science problem multiple choice

Answer:

Plasma estrogen levels reach their peak at the end of the luteal phase of the ovarian cycle.

a. True

Explanation:

A woman's estrogen levels become highest towards the end of her ovulation.  At this point, the woman is naturally prepared for a possible pregnancy.  The occurrence of the highest estrogen levels coincides with the luteal phase, a stage of a woman's menstrual cycle, which occurs after ovulation (or the release of eggs from the ovaries), and before the start of the normal period. This luteal phase has been observed to be within 14 days for all women.  By the end of the luteal phase, the corpus luteum function declines.

Answer:

Variation

Explanation:

Migration into a population from other populations with varying gene frequencies, evolution, or adaptation of heat tolerance is a cause of variation. The allele frequency of the resulting hybrid population would be right in the middle of its original value and the donor population's frequency. In tropical and subtropical ecosystems (Sahara deserts), high temperatures are a significant restriction to human population productivity; they induce morphological and physiological modifications at all times, resulting in significant yield losses but the ability and evolution of human species to cope in this region is as a result of variation.

Answer:

C

Explanation:

I took the test a few days ago. :)

Answer:

Ok so

Explanation:

1. DNA

2.A , G , C and T

3.The 3-dimensional double helix structure of DNA, correctly elucidated by James Watson and Francis Crick. Complementary bases are held together as a pair by hydrogen bonds.

4.Chargaff's realization that A = T and C = G, combined with some crucially important X-ray crystallography work by English researchers Rosalind Franklin and Maurice Wilkins, contributed to Watson and Crick's derivation of the three-dimensional, double-helical model for the structure of DNA.

5.Created by Rosalind Franklin using a technique called X-ray crystallography, it revealed the helical shape of the DNA molecule. Watson and Crick realized that DNA was made up of two chains of nucleotide pairs that encode the genetic information for all living things.

6. 1869

7.The double helix of DNA is, like its name implies, in the shape of a helix which is essentially a three dimensional spiral. The double comes from the fact that the helix is made of two long strands of DNA that are intertwined—sort of like a twisted ladder.

8. In DNA, the code letters are A, T, G, and C, which stand for the chemicals adenine, thymine, guanine, and cytosine, respectively. In base pairing, adenine always pairs with thymine, and guanine always pairs with cytosine.

9. A gene is the basic physical and functional unit of heredity. Genes are made up of DNA. Some genes act as instructions to make molecules called proteins. ... Every person has two copies of each gene, one inherited from each parent.

10. 20

11. A group of disorders that cause red blood cells to become misshapen and break down.

With sickle cell disease, an inherited group of disorders, red blood cells contort into a sickle shape. The cells die early, leaving a shortage of healthy red blood cells (sickle cell anaemia) and can block blood flow causing pain (sickle cell crisis).

12. Sickle cell anemia is caused by a mutation in the gene that tells your body to make the iron-rich compound that makes blood red and enables red blood cells to carry oxygen from your lungs throughout your body (hemoglobin).

13. The Human Genome Project was an international scientific research project with the goal of determining the base pairs that make up human DNA, and of identifying and mapping all of the genes of the human genome from both a physical and a functional standpoint.

I'm so absolutely sorry if this is long. Good lucj with ur work ;D

Answer:

C

Explanation:

the number and percentage of eukaryotic species that are still to be formally described is to be beauty

Eukaryotic organisms are species that have defined nucleus and membrane limited organelles. Total 11% or 250,000 are described while 97% or 8490000 are yet to be described.

Eukaryotes are the largest and the most dominating species that includes kingdom plants, animals, fungi and protists. A total of  8.74 million eukaryote species on Earth are present from which only 250,000 are described.

Eukaryotes are the species that are well-defined organisms that contain the genetic material enclosed within the nuclear membrane and the organelles are also enclosed.

With new discoveries and findings, many new species are described that are grouped into one of the kingdoms based on their properties and features.

Therefore, 8.74 million eukaryote species are present on Earth.

Learn more about eukaryotes here:

https://brainly.com/question/4944603

Answer:

Codominance- Two traits are both present in a third phenotype.

Incomplete Dominance- Two traits blend to form a third phenotype.

Sex-Linked Traits- Determined by gene located on sex chromosomes.

Explanation:

I hope this helps.

So there are a lot of people who say that the Dark Ages, lasting about 1,000 years, set humans back technologically. However, some say that since the Dark Ages really only affected Western Europe, and not the Middle East or Asia, it wouldn't make a difference.

If there had been no "Dark Ages" there would have been no Renaissance. Historians actually argue about when Renaissance started, and the answer is than it is not possible to pinpoint a date. The Crusade did more to bring the eastern world to western Europe than they did to divide.

Answer:

Chomosomes are duplicated during interphase

Brainliest?

The first thing Fiona, or anyone, should do is form her hypothesis.

The hypothesis is your own proposed explanation for whatever phenomenon you're trying to study. Think of it as a predetermined idea of what could happen based on what you already know.

Answer:

The correct answer is D!:)

Explanation:

Hope this helps!:)

Answer:

the tundra biome :)

Explanation:

grass lands aren't very cold

forests aren't cold

the desert is hot

and tundra is super cold

Answer:

The conclusion to be drawn from the fact that secondary consumers do not digest the bones of their prey is that energy used to create bone mass often does not travel farther up the food chain . Explanation: ... No energy is required to form bones .

Explanation:

Answer:hebivore

Explanation:

Answer:

B. The number of grasshopers would go up.

Explanation:

A. is incorrect because it would decrease

C is incorrect  because it would also decrease

D is incorrect because snakes dont eat Hawks, but Hawks eat them

B is correct because since snakes would eat the toads, there would be no toads eating grasshoppers

Hope this helps!!!

Answer:

E  B  I F H A D G C

Explanation:

Answer:

inside the phage ghosts outside the bacterial cells.

Explanation:

According to Hershey & Chase- Experiments, the radioisotope 35S is frequently associated with protein since sulfur is a protein component.  The radioactive sulfur is absorbed into the protein coat because it already contained sulfur (35S).  The radioactive marker 35S was integrated into the Bacteriophage protein coat and remained as phage ghosts outside the bacterial cells.

Answer:

Increased Joint Mobility

Answer:

b

Explanation:

Answer:

D

Explanation:

I think its d

Answer:

is B

Explanation:

volcanic activity was more common in the past than it is today.